BYTE.ARTICLE
FILE INFORMATION
FILENAME(S): BYTE.ARTICLE
FILE TYPE(S): SEQ
FILE SIZE: 79.9K
FIRST SEEN: 2025-10-20 14:31:06
APPEARS ON: 3 disk(s)
FILE HASH
c73dfe8e194896b879f93e4f42f72e9336e3858b64192c3a4d118ed7d3161f2c
FOUND ON DISKS (3 DISKS)
| DISK TITLE | FILENAME | FILE TYPE | COLLECTION | TRACK | SECTOR | ACTIONS |
|---|---|---|---|---|---|---|
| MASTERMMSOFT | BYTE.ARTICLE | SEQ | Treasure Chest - Klaus Der Suhler | 24 | 7 | DOWNLOAD FILE |
| KERMIT HELPFILES | BYTE.ARTICLE | SEQ | Treasure Chest - Klaus Der Suhler | 24 | 7 | DOWNLOAD FILE |
| SD | BYTE.ARTICLE | SEQ | HOL2001, Misc | 24 | 7 | DOWNLOAD FILE |
FILE CONTENT & ANALYSIS
00000000: 0D 46 49 4C 45 3A C2 D9 D4 C5 2E C4 CF C3 20 2F |.FILE:........ /|
00000010: 20 46 52 4F 4D 3A CB C5 D2 CD D3 D2 D6 20 41 54 | FROM:....... AT|
00000020: 20 C3 D5 D6 CD C1 2E C2 C9 D4 CE C5 D4 20 2F 20 | ............ / |
00000030: 54 52 41 4E 53 46 45 52 20 42 59 20 C8 C1 C9 0D |TRANSFER BY ....|
00000040: 0D 0D CB C5 D2 CD C9 D4 0D 3D 3D 3D 3D 3D 3D 0D |.........======.|
00000050: 0D D4 48 49 53 20 49 53 20 54 48 45 20 4F 52 49 |..HIS IS THE ORI|
00000060: 47 49 4E 41 4C 20 4D 41 4E 55 53 43 52 49 50 54 |GINAL MANUSCRIPT|
00000070: 20 4F 46 20 54 48 45 20 41 52 54 49 43 4C 45 20 | OF THE ARTICLE |
00000080: 50 55 42 4C 49 53 48 45 44 20 49 4E 20 C2 D9 D4 |PUBLISHED IN ...|
00000090: C5 20 CD 41 47 41 5A 49 4E 45 20 41 53 0D 22 CB |. .AGAZINE AS.".|
000000A0: 45 52 4D 49 54 3A 20 C1 20 C6 49 4C 45 20 D4 52 |ERMIT: . .ILE .R|
000000B0: 41 4E 53 46 45 52 20 D0 52 4F 54 4F 43 4F 4C 20 |ANSFER .ROTOCOL |
000000C0: 46 4F 52 20 D5 4E 49 56 45 52 53 49 54 49 45 53 |FOR .NIVERSITIES|
000000D0: 22 2C 20 CA 55 4E 45 20 41 4E 44 20 CA 55 4C 59 |", .UNE AND .ULY|
000000E0: 20 31 39 38 34 2E 0D D3 4F 4D 45 20 4D 49 4E 4F | 1984...OME MINO|
000000F0: 52 20 45 44 49 54 4F 52 49 41 4C 20 44 49 46 46 |R EDITORIAL DIFF|
00000100: 45 52 45 4E 43 45 53 20 45 58 49 53 54 20 42 45 |ERENCES EXIST BE|
00000110: 54 57 45 45 4E 20 54 48 49 53 20 4D 41 4E 55 53 |TWEEN THIS MANUS|
00000120: 43 52 49 50 54 20 41 4E 44 20 54 48 45 20 41 52 |CRIPT AND THE AR|
00000130: 54 49 43 4C 45 0D 41 53 20 50 55 42 4C 49 53 48 |TICLE.AS PUBLISH|
00000140: 45 44 2E 20 D4 48 45 20 CB 45 52 4D 49 54 20 46 |ED. .HE .ERMIT F|
00000150: 49 4C 45 20 54 52 41 4E 53 46 45 52 20 50 52 4F |ILE TRANSFER PRO|
00000160: 54 4F 43 4F 4C 20 49 53 20 4E 41 4D 45 44 20 41 |TOCOL IS NAMED A|
00000170: 46 54 45 52 20 CB 45 52 4D 49 54 20 54 48 45 20 |FTER .ERMIT THE |
00000180: C6 52 4F 47 2C 0D 53 54 41 52 20 4F 46 20 54 48 |.ROG,.STAR OF TH|
00000190: 45 20 54 45 4C 45 56 49 53 49 4F 4E 20 53 45 52 |E TELEVISION SER|
000001A0: 49 45 53 20 D4 C8 C5 20 CD D5 D0 D0 C5 D4 20 D3 |IES ... ...... .|
000001B0: C8 CF D7 2C 20 55 53 45 44 20 42 59 20 50 45 52 |..., USED BY PER|
000001C0: 4D 49 53 53 49 4F 4E 20 4F 46 20 C8 45 4E 53 4F |MISSION OF .ENSO|
000001D0: 4E 0D C1 53 53 4F 43 49 41 54 45 53 2C 20 C9 4E |N..SSOCIATES, .N|
000001E0: 43 2E 0D 0D 0D C1 20 D3 49 4D 50 4C 45 20 C6 49 |C..... .IMPLE .I|
000001F0: 4C 45 20 D4 52 41 4E 53 46 45 52 20 D0 52 4F 54 |LE .RANSFER .ROT|
00000200: 4F 43 4F 4C 20 46 4F 52 20 CD 49 43 52 4F 43 4F |OCOL FOR .ICROCO|
00000210: 4D 50 55 54 45 52 53 20 41 4E 44 20 CD 41 49 4E |MPUTERS AND .AIN|
00000220: 46 52 41 4D 45 53 0D 0D 0D C6 52 41 4E 4B 20 44 |FRAMES....RANK D|
00000230: 41 20 C3 52 55 5A 2C 20 C2 49 4C 4C 20 C3 41 54 |A .RUZ, .ILL .AT|
00000240: 43 48 49 4E 47 53 0D C3 4F 4C 55 4D 42 49 41 20 |CHINGS..OLUMBIA |
00000250: D5 4E 49 56 45 52 53 49 54 59 20 C3 45 4E 54 45 |.NIVERSITY .ENTE|
00000260: 52 20 46 4F 52 20 C3 4F 4D 50 55 54 49 4E 47 20 |R FOR .OMPUTING |
00000270: C1 43 54 49 56 49 54 49 45 53 0D CE 45 57 20 D9 |.CTIVITIES..EW .|
00000280: 4F 52 4B 2C 20 CE 2E D9 2E 20 20 31 30 30 32 37 |ORK, .... 10027|
00000290: 0D CD 41 59 20 31 39 38 33 0D 0D 0D C4 55 52 49 |..AY 1983....URI|
000002A0: 4E 47 20 52 45 43 45 4E 54 20 59 45 41 52 53 2C |NG RECENT YEARS,|
000002B0: 20 54 48 45 20 54 45 43 48 4E 49 43 41 4C 20 50 | THE TECHNICAL P|
000002C0: 52 45 53 53 20 48 41 53 20 46 4F 43 55 53 45 44 |RESS HAS FOCUSED|
000002D0: 20 41 20 4C 4F 54 20 4F 46 20 41 54 54 45 4E 54 | A LOT OF ATTENT|
000002E0: 49 4F 4E 20 4F 4E 0D 44 45 56 45 4C 4F 50 4D 45 |ION ON.DEVELOPME|
000002F0: 4E 54 53 20 49 4E 20 43 4F 4D 50 55 54 45 52 20 |NTS IN COMPUTER |
00000300: 4E 45 54 57 4F 52 4B 49 4E 47 20 2D 20 54 48 45 |NETWORKING - THE|
00000310: 20 C9 C5 C5 C5 20 38 30 32 20 43 4F 4D 4D 49 54 | .... 802 COMMIT|
00000320: 54 45 45 2C 20 D4 C3 D0 2F C9 D0 2C 20 D3 CE C1 |TEE, .../.., ...|
00000330: 2C 0D 54 48 45 20 4C 41 54 45 53 54 20 D6 CC D3 |,.THE LATEST ...|
00000340: C9 20 C5 54 48 45 52 4E 45 54 20 49 4E 54 45 52 |. .THERNET INTER|
00000350: 46 41 43 45 2C 20 46 49 42 52 45 20 4F 50 54 49 |FACE, FIBRE OPTI|
00000360: 43 53 2C 20 53 41 54 45 4C 4C 49 54 45 20 43 4F |CS, SATELLITE CO|
00000370: 4D 4D 55 4E 49 43 41 54 49 4F 4E 53 2C 0D 42 52 |MMUNICATIONS,.BR|
00000380: 4F 41 44 42 41 4E 44 20 56 45 52 53 55 53 20 42 |OADBAND VERSUS B|
00000390: 41 53 45 42 41 4E 44 2E 20 20 C2 55 54 20 4C 49 |ASEBAND. .UT LI|
000003A0: 54 54 4C 45 20 41 54 54 45 4E 54 49 4F 4E 20 48 |TTLE ATTENTION H|
000003B0: 41 53 20 42 45 45 4E 20 47 49 56 45 4E 20 54 4F |AS BEEN GIVEN TO|
000003C0: 20 54 48 45 20 53 49 4E 47 4C 45 0D 4D 45 43 48 | THE SINGLE.MECH|
000003D0: 41 4E 49 53 4D 20 54 48 41 54 20 4D 41 59 20 42 |ANISM THAT MAY B|
000003E0: 45 20 54 48 45 20 4D 4F 53 54 20 57 49 44 45 4C |E THE MOST WIDEL|
000003F0: 59 20 55 53 45 44 20 49 4E 20 54 48 45 20 52 45 |Y USED IN THE RE|
00000400: 41 4C 20 57 4F 52 4C 44 20 46 4F 52 20 44 49 52 |AL WORLD FOR DIR|
00000410: 45 43 54 20 49 4E 54 45 52 2D 0D 50 52 4F 43 45 |ECT INTER-.PROCE|
00000420: 53 53 4F 52 20 43 4F 4D 4D 55 4E 49 43 41 54 49 |SSOR COMMUNICATI|
00000430: 4F 4E 3A 20 54 48 45 20 53 4F 2D 43 41 4C 4C 45 |ON: THE SO-CALLE|
00000440: 44 20 22 41 53 59 4E 43 48 52 4F 4E 4F 55 53 20 |D "ASYNCHRONOUS |
00000450: 50 52 4F 54 4F 43 4F 4C 22 2C 20 57 48 49 43 48 |PROTOCOL", WHICH|
00000460: 20 49 53 20 54 4F 20 42 45 0D 46 4F 55 4E 44 20 | IS TO BE.FOUND |
00000470: 49 4E 20 53 4F 4D 45 20 46 4F 52 4D 20 41 54 20 |IN SOME FORM AT |
00000480: 41 4C 4D 4F 53 54 20 45 56 45 52 59 20 49 4E 53 |ALMOST EVERY INS|
00000490: 54 49 54 55 54 49 4F 4E 20 57 48 45 52 45 20 54 |TITUTION WHERE T|
000004A0: 48 45 52 45 20 49 53 20 41 20 4E 45 45 44 20 54 |HERE IS A NEED T|
000004B0: 4F 0D 54 52 41 4E 53 46 45 52 20 46 49 4C 45 53 |O.TRANSFER FILES|
000004C0: 20 42 45 54 57 45 45 4E 20 4D 49 43 52 4F 43 4F | BETWEEN MICROCO|
000004D0: 4D 50 55 54 45 52 53 20 41 4E 44 20 43 45 4E 54 |MPUTERS AND CENT|
000004E0: 52 41 4C 20 43 4F 4D 50 55 54 45 52 53 2E 0D 0D |RAL COMPUTERS...|
000004F0: C3 4F 4C 55 4D 42 49 41 20 D5 4E 49 56 45 52 53 |.OLUMBIA .NIVERS|
00000500: 49 54 59 20 49 53 20 53 55 43 48 20 41 4E 20 49 |ITY IS SUCH AN I|
00000510: 4E 53 54 49 54 55 54 49 4F 4E 2E 20 20 CC 41 52 |NSTITUTION. .AR|
00000520: 47 45 20 54 49 4D 45 53 48 41 52 49 4E 47 20 43 |GE TIMESHARING C|
00000530: 4F 4D 50 55 54 45 52 53 20 41 54 20 41 0D 43 45 |OMPUTERS AT A.CE|
00000540: 4E 54 52 41 4C 20 53 49 54 45 20 41 52 45 20 43 |NTRAL SITE ARE C|
00000550: 4F 4D 50 4C 45 4D 45 4E 54 45 44 20 42 59 20 4D |OMPLEMENTED BY M|
00000560: 41 4E 59 20 53 4D 41 4C 4C 45 52 20 53 59 53 54 |ANY SMALLER SYST|
00000570: 45 4D 53 20 53 43 41 54 54 45 52 45 44 20 49 4E |EMS SCATTERED IN|
00000580: 20 54 48 45 0D 4C 41 42 4F 52 41 54 4F 52 49 45 | THE.LABORATORIE|
00000590: 53 20 41 4E 44 20 44 45 50 41 52 54 4D 45 4E 54 |S AND DEPARTMENT|
000005A0: 53 2E 20 20 D4 48 45 20 50 41 53 54 20 46 45 57 |S. .HE PAST FEW|
000005B0: 20 59 45 41 52 53 20 48 41 56 45 20 57 49 54 4E | YEARS HAVE WITN|
000005C0: 45 53 53 45 44 20 54 48 45 20 49 4E 45 58 4F 52 |ESSED THE INEXOR|
000005D0: 41 42 4C 45 0D 50 52 4F 47 52 45 53 53 20 4F 46 |ABLE.PROGRESS OF|
000005E0: 20 44 49 56 45 52 53 45 20 4D 49 43 52 4F 43 4F | DIVERSE MICROCO|
000005F0: 4D 50 55 54 45 52 53 2C 20 57 4F 52 44 20 50 52 |MPUTERS, WORD PR|
00000600: 4F 43 45 53 53 4F 52 53 2C 20 41 4E 44 20 50 52 |OCESSORS, AND PR|
00000610: 4F 46 45 53 53 49 4F 4E 41 4C 20 57 4F 52 4B 2D |OFESSIONAL WORK-|
00000620: 0D 53 54 41 54 49 4F 4E 53 20 49 4E 54 4F 20 4F |.STATIONS INTO O|
00000630: 46 46 49 43 45 53 20 41 4E 44 20 4C 41 42 4F 52 |FFICES AND LABOR|
00000640: 41 54 4F 52 49 45 53 20 54 48 52 4F 55 47 48 4F |ATORIES THROUGHO|
00000650: 55 54 20 54 48 45 20 D5 4E 49 56 45 52 53 49 54 |UT THE .NIVERSIT|
00000660: 59 2C 20 41 4E 44 20 49 4E 54 4F 20 54 48 45 0D |Y, AND INTO THE.|
00000670: 48 4F 4D 45 53 20 4F 52 20 44 4F 52 4D 49 54 4F |HOMES OR DORMITO|
00000680: 52 59 20 52 4F 4F 4D 53 20 4F 46 20 46 41 43 55 |RY ROOMS OF FACU|
00000690: 4C 54 59 2C 20 53 54 55 44 45 4E 54 53 2C 20 41 |LTY, STUDENTS, A|
000006A0: 4E 44 20 53 54 41 46 46 2E 20 20 C1 53 20 53 4F |ND STAFF. .S SO|
000006B0: 4F 4E 20 41 53 20 54 48 45 53 45 0D 53 4D 41 4C |ON AS THESE.SMAL|
000006C0: 4C 20 4D 41 43 48 49 4E 45 53 20 42 45 47 41 4E |L MACHINES BEGAN|
000006D0: 20 54 4F 20 41 50 50 45 41 52 2C 20 54 48 45 49 | TO APPEAR, THEI|
000006E0: 52 20 55 53 45 52 53 20 41 53 4B 45 44 20 46 4F |R USERS ASKED FO|
000006F0: 52 20 57 41 59 53 20 54 4F 20 45 58 43 48 41 4E |R WAYS TO EXCHAN|
00000700: 47 45 20 46 49 4C 45 53 0D 57 49 54 48 20 54 48 |GE FILES.WITH TH|
00000710: 45 20 43 45 4E 54 52 41 4C 20 41 4E 44 20 44 45 |E CENTRAL AND DE|
00000720: 50 41 52 54 4D 45 4E 54 41 4C 20 53 59 53 54 45 |PARTMENTAL SYSTE|
00000730: 4D 53 2E 0D 0D C1 54 20 54 48 45 20 53 41 4D 45 |MS....T THE SAME|
00000740: 20 54 49 4D 45 2C 20 53 54 55 44 45 4E 54 20 55 | TIME, STUDENT U|
00000750: 53 45 20 4F 46 20 4F 55 52 20 43 45 4E 54 52 41 |SE OF OUR CENTRA|
00000760: 4C 20 53 59 53 54 45 4D 53 20 57 41 53 20 47 52 |L SYSTEMS WAS GR|
00000770: 4F 57 49 4E 47 20 41 54 20 41 4E 0D 41 53 54 4F |OWING AT AN.ASTO|
00000780: 4E 49 53 48 49 4E 47 20 52 41 54 45 2E 20 D7 45 |NISHING RATE. .E|
00000790: 20 43 4F 55 4C 44 20 4E 4F 20 4C 4F 4E 47 45 52 | COULD NO LONGER|
000007A0: 20 41 46 46 4F 52 44 20 54 4F 20 50 52 4F 56 49 | AFFORD TO PROVI|
000007B0: 44 45 20 53 54 55 44 45 4E 54 53 20 57 49 54 48 |DE STUDENTS WITH|
000007C0: 20 50 45 52 50 45 54 55 41 4C 0D 4F 4E 4C 49 4E | PERPETUAL.ONLIN|
000007D0: 45 20 44 49 53 4B 20 53 54 4F 52 41 47 45 3B 20 |E DISK STORAGE; |
000007E0: 57 45 20 42 45 47 41 4E 20 54 4F 20 49 53 53 55 |WE BEGAN TO ISSU|
000007F0: 45 20 C9 C4 53 20 50 45 52 20 43 4F 55 52 53 45 |E ..S PER COURSE|
00000800: 2C 20 50 45 52 20 54 45 52 4D 2E 20 20 D7 49 54 |, PER TERM. .IT|
00000810: 48 20 54 48 45 0D 44 45 43 52 45 41 53 45 44 20 |H THE.DECREASED |
00000820: 4C 4F 4E 47 45 56 49 54 59 20 4F 46 20 54 48 45 |LONGEVITY OF THE|
00000830: 20 C9 C4 53 20 43 41 4D 45 20 54 48 45 20 4E 45 | ..S CAME THE NE|
00000840: 45 44 20 46 4F 52 20 53 54 55 44 45 4E 54 53 20 |ED FOR STUDENTS |
00000850: 54 4F 20 45 43 4F 4E 4F 4D 49 43 41 4C 4C 59 0D |TO ECONOMICALLY.|
00000860: 41 52 43 48 49 56 45 20 54 48 45 49 52 20 46 49 |ARCHIVE THEIR FI|
00000870: 4C 45 53 2E 20 20 C7 49 56 45 4E 20 41 20 52 45 |LES. .IVEN A RE|
00000880: 4C 49 41 42 4C 45 20 57 41 59 20 54 4F 20 46 52 |LIABLE WAY TO FR|
00000890: 4F 4D 20 54 48 45 20 43 45 4E 54 52 41 4C 20 4D |OM THE CENTRAL M|
000008A0: 41 49 4E 46 52 41 4D 45 53 20 41 4E 44 0D 42 41 |AINFRAMES AND.BA|
000008B0: 43 4B 2C 20 4D 49 43 52 4F 43 4F 4D 50 55 54 45 |CK, MICROCOMPUTE|
000008C0: 52 53 20 57 49 54 48 20 46 4C 4F 50 50 59 20 44 |RS WITH FLOPPY D|
000008D0: 49 53 4B 53 20 43 4F 55 4C 44 20 50 52 4F 56 49 |ISKS COULD PROVI|
000008E0: 44 45 20 49 4E 45 58 50 45 4E 53 49 56 45 20 52 |DE INEXPENSIVE R|
000008F0: 45 4D 4F 56 41 42 4C 45 0D 4D 45 44 49 41 20 49 |EMOVABLE.MEDIA I|
00000900: 44 45 41 4C 20 46 4F 52 20 54 48 49 53 20 50 55 |DEAL FOR THIS PU|
00000910: 52 50 4F 53 45 2E 0D 0D D4 48 45 20 53 49 54 55 |RPOSE....HE SITU|
00000920: 41 54 49 4F 4E 20 43 41 4C 4C 45 44 20 46 4F 52 |ATION CALLED FOR|
00000930: 20 41 20 46 49 4C 45 20 54 52 41 4E 53 46 45 52 | A FILE TRANSFER|
00000940: 20 4D 45 43 48 41 4E 49 53 4D 20 54 48 41 54 20 | MECHANISM THAT |
00000950: 43 4F 55 4C 44 20 57 4F 52 4B 20 41 4D 4F 4E 47 |COULD WORK AMONG|
00000960: 20 41 4C 4C 0D 4F 55 52 20 43 4F 4D 50 55 54 45 | ALL.OUR COMPUTE|
00000970: 52 53 2C 20 4C 41 52 47 45 20 41 4E 44 20 53 4D |RS, LARGE AND SM|
00000980: 41 4C 4C 2E 20 20 D7 45 20 4B 4E 45 57 20 4F 46 |ALL. .E KNEW OF|
00000990: 20 4E 4F 4E 45 20 54 48 41 54 20 43 4F 55 4C 44 | NONE THAT COULD|
000009A0: 20 48 41 4E 44 4C 45 20 54 48 45 20 52 45 51 55 | HANDLE THE REQU|
000009B0: 49 52 45 44 0D 44 49 56 45 52 53 49 54 59 2E 20 |IRED.DIVERSITY. |
000009C0: 20 D3 4F 4D 45 20 57 45 52 45 20 49 4E 54 45 4E | .OME WERE INTEN|
000009D0: 44 45 44 20 46 4F 52 20 55 53 45 20 42 45 54 57 |DED FOR USE BETW|
000009E0: 45 45 4E 20 4D 49 43 52 4F 43 4F 4D 50 55 54 45 |EEN MICROCOMPUTE|
000009F0: 52 53 2C 20 4F 54 48 45 52 53 20 42 45 54 57 45 |RS, OTHERS BETWE|
00000A00: 45 4E 0D 4C 41 52 47 45 20 43 4F 4D 50 55 54 45 |EN.LARGE COMPUTE|
00000A10: 52 53 2C 20 42 55 54 20 4E 4F 4E 45 20 53 50 45 |RS, BUT NONE SPE|
00000A20: 43 49 46 49 43 41 4C 4C 59 20 41 44 44 52 45 53 |CIFICALLY ADDRES|
00000A30: 53 45 44 20 54 48 45 20 4E 45 45 44 20 46 4F 52 |SED THE NEED FOR|
00000A40: 20 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E 0D 41 | COMMUNICATION.A|
00000A50: 4D 4F 4E 47 20 54 48 45 20 57 49 44 45 53 54 20 |MONG THE WIDEST |
00000A60: 50 4F 53 53 49 42 4C 45 20 52 41 4E 47 45 20 4F |POSSIBLE RANGE O|
00000A70: 46 20 43 4F 4D 50 55 54 45 52 53 2C 20 50 41 52 |F COMPUTERS, PAR|
00000A80: 54 49 43 55 4C 41 52 4C 59 20 42 45 54 57 45 45 |TICULARLY BETWEE|
00000A90: 4E 20 4D 49 43 52 4F 53 20 41 4E 44 0D 4F 55 52 |N MICROS AND.OUR|
00000AA0: 20 C9 C2 CD 20 41 4E 44 20 C4 C5 C3 20 4D 41 49 | ... AND ... MAI|
00000AB0: 4E 46 52 41 4D 45 53 2E 20 20 CD 4F 53 54 20 43 |NFRAMES. .OST C|
00000AC0: 4F 4D 4D 45 52 43 49 41 4C 20 50 41 43 4B 41 47 |OMMERCIAL PACKAG|
00000AD0: 45 53 20 53 45 52 56 45 44 20 41 20 4C 49 4D 49 |ES SERVED A LIMI|
00000AE0: 54 45 44 20 53 45 54 20 4F 46 0D 53 59 53 54 45 |TED SET OF.SYSTE|
00000AF0: 4D 53 2C 20 41 4E 44 20 54 48 45 49 52 20 43 4F |MS, AND THEIR CO|
00000B00: 53 54 20 57 4F 55 4C 44 20 48 41 56 45 20 42 45 |ST WOULD HAVE BE|
00000B10: 45 4E 20 50 52 4F 48 49 42 49 54 49 56 45 20 57 |EN PROHIBITIVE W|
00000B20: 48 45 4E 20 4D 55 4C 54 49 50 4C 49 45 44 20 42 |HEN MULTIPLIED B|
00000B30: 59 20 54 48 45 0D 4C 41 52 47 45 20 4E 55 4D 42 |Y THE.LARGE NUMB|
00000B40: 45 52 20 4F 46 20 4D 41 43 48 49 4E 45 53 20 57 |ER OF MACHINES W|
00000B50: 45 20 4E 45 45 44 45 44 20 54 4F 20 53 55 50 50 |E NEEDED TO SUPP|
00000B60: 4F 52 54 2E 0D 0D D3 4F 20 57 45 20 45 4D 42 41 |ORT....O WE EMBA|
00000B70: 52 4B 45 44 20 4F 4E 20 4F 55 52 20 4F 57 4E 20 |RKED ON OUR OWN |
00000B80: 50 52 4F 4A 45 43 54 2E 20 20 D7 45 20 57 45 52 |PROJECT. .E WER|
00000B90: 45 20 4E 4F 54 20 57 45 4C 4C 2D 56 45 52 53 45 |E NOT WELL-VERSE|
00000BA0: 44 20 49 4E 20 54 48 45 53 45 20 4D 41 54 54 45 |D IN THESE MATTE|
00000BB0: 52 53 0D 41 54 20 54 48 45 20 4F 55 54 53 45 54 |RS.AT THE OUTSET|
00000BC0: 3B 20 57 45 20 4C 45 41 52 4E 45 44 20 41 53 20 |; WE LEARNED AS |
00000BD0: 57 45 20 50 52 4F 43 45 45 44 45 44 2C 20 41 4E |WE PROCEEDED, AN|
00000BE0: 44 20 57 45 27 52 45 20 53 54 49 4C 4C 20 4C 45 |D WE'RE STILL LE|
00000BF0: 41 52 4E 49 4E 47 2E 20 20 D4 48 49 53 0D 41 52 |ARNING. .HIS.AR|
00000C00: 54 49 43 4C 45 20 44 49 53 43 55 53 53 45 53 20 |TICLE DISCUSSES |
00000C10: 53 4F 4D 45 20 4F 46 20 54 48 45 20 49 53 53 55 |SOME OF THE ISSU|
00000C20: 45 53 20 41 4E 44 20 54 52 41 44 45 4F 46 46 53 |ES AND TRADEOFFS|
00000C30: 20 54 48 41 54 20 43 41 4D 45 20 55 50 20 49 4E | THAT CAME UP IN|
00000C40: 20 54 48 45 20 44 45 53 49 47 4E 2C 0D 41 4E 44 | THE DESIGN,.AND|
00000C50: 20 49 4C 4C 55 53 54 52 41 54 45 53 20 54 48 45 | ILLUSTRATES THE|
00000C60: 4D 20 49 4E 20 54 45 52 4D 53 20 4F 46 20 4F 55 |M IN TERMS OF OU|
00000C70: 52 20 52 45 53 55 4C 54 2C 20 54 48 45 20 CB C5 |R RESULT, THE ..|
00000C80: D2 CD C9 D4 20 50 52 4F 54 4F 43 4F 4C 20 46 4F |.... PROTOCOL FO|
00000C90: 52 0D 50 4F 49 4E 54 2D 54 4F 2D 50 4F 49 4E 54 |R.POINT-TO-POINT|
00000CA0: 20 46 49 4C 45 20 54 52 41 4E 53 46 45 52 20 4F | FILE TRANSFER O|
00000CB0: 56 45 52 20 54 45 4C 45 43 4F 4D 4D 55 4E 49 43 |VER TELECOMMUNIC|
00000CC0: 41 54 49 4F 4E 20 4C 49 4E 45 53 2E 20 20 C2 45 |ATION LINES. .E|
00000CD0: 43 41 55 53 45 20 43 4F 4D 4D 45 52 43 49 41 4C |CAUSE COMMERCIAL|
00000CE0: 0D 4C 4F 43 41 4C 20 41 52 45 41 20 4E 45 54 57 |.LOCAL AREA NETW|
00000CF0: 4F 52 4B 49 4E 47 20 50 52 4F 44 55 43 54 53 20 |ORKING PRODUCTS |
00000D00: 41 52 45 20 45 58 50 45 4E 53 49 56 45 2C 20 4E |ARE EXPENSIVE, N|
00000D10: 4F 54 20 59 45 54 20 57 49 44 45 4C 59 20 41 56 |OT YET WIDELY AV|
00000D20: 41 49 4C 41 42 4C 45 2C 20 41 4E 44 0D 55 4E 53 |AILABLE, AND.UNS|
00000D30: 55 49 54 41 42 4C 45 20 46 4F 52 20 4F 4E 45 2D |UITABLE FOR ONE-|
00000D40: 53 48 4F 54 20 4F 52 20 4C 4F 4E 47 2D 48 41 55 |SHOT OR LONG-HAU|
00000D50: 4C 20 41 50 50 4C 49 43 41 54 49 4F 4E 53 2C 20 |L APPLICATIONS, |
00000D60: 48 55 4D 42 4C 45 20 41 53 59 4E 43 48 52 4F 4E |HUMBLE ASYNCHRON|
00000D70: 4F 55 53 0D 50 52 4F 54 4F 43 4F 4C 53 20 53 55 |OUS.PROTOCOLS SU|
00000D80: 43 48 20 41 53 20 CB C5 D2 CD C9 D4 20 41 52 45 |CH AS ...... ARE|
00000D90: 20 4C 49 4B 45 4C 59 20 54 4F 20 42 45 20 57 49 | LIKELY TO BE WI|
00000DA0: 54 48 20 55 53 20 46 4F 52 20 41 20 4C 4F 4E 47 |TH US FOR A LONG|
00000DB0: 20 54 49 4D 45 20 54 4F 20 43 4F 4D 45 2E 0D 0D | TIME TO COME...|
00000DC0: C9 54 20 49 53 20 41 53 53 55 4D 45 44 20 54 48 |.T IS ASSUMED TH|
00000DD0: 45 20 52 45 41 44 45 52 20 49 53 20 46 41 4D 49 |E READER IS FAMI|
00000DE0: 4C 49 41 52 20 57 49 54 48 20 43 4F 4D 4D 4F 4E |LIAR WITH COMMON|
00000DF0: 20 43 4F 4D 50 55 54 49 4E 47 20 41 4E 44 20 54 | COMPUTING AND T|
00000E00: 45 4C 45 43 4F 4D 4D 55 4E 49 43 41 2D 0D 54 49 |ELECOMMUNICA-.TI|
00000E10: 4F 4E 53 20 54 45 52 4D 49 4E 4F 4C 4F 47 59 2C |ONS TERMINOLOGY,|
00000E20: 20 41 4E 44 20 57 49 54 48 20 54 48 45 20 C1 D3 | AND WITH THE ..|
00000E30: C3 C9 C9 20 41 4C 50 48 41 42 45 54 2C 20 57 48 |... ALPHABET, WH|
00000E40: 49 43 48 20 49 53 20 4C 49 53 54 45 44 20 41 54 |ICH IS LISTED AT|
00000E50: 20 54 48 45 20 45 4E 44 20 4F 46 0D 54 48 49 53 | THE END OF.THIS|
00000E60: 20 41 52 54 49 43 4C 45 20 46 4F 52 20 52 45 46 | ARTICLE FOR REF|
00000E70: 45 52 45 4E 43 45 2E 0D 0D 0D D4 48 45 20 C3 4F |ERENCE.....HE .O|
00000E80: 4D 4D 55 4E 49 43 41 54 49 4F 4E 20 CD 45 44 49 |MMUNICATION .EDI|
00000E90: 55 4D 0D 0D D4 48 45 20 4F 4E 4C 59 20 43 4F 4D |UM...HE ONLY COM|
00000EA0: 4D 55 4E 49 43 41 54 49 4F 4E 20 4D 45 44 49 55 |MUNICATION MEDIU|
00000EB0: 4D 20 43 4F 4D 4D 4F 4E 20 54 4F 20 41 4C 4C 20 |M COMMON TO ALL |
00000EC0: 43 4F 4D 50 55 54 45 52 53 2C 20 4C 41 52 47 45 |COMPUTERS, LARGE|
00000ED0: 20 41 4E 44 20 53 4D 41 4C 4C 2C 20 49 53 20 54 | AND SMALL, IS T|
00000EE0: 48 45 0D 41 53 59 4E 43 48 52 4F 4E 4F 55 53 20 |HE.ASYNCHRONOUS |
00000EF0: 53 45 52 49 41 4C 20 54 45 4C 45 43 4F 4D 4D 55 |SERIAL TELECOMMU|
00000F00: 4E 49 43 41 54 49 4F 4E 20 4C 49 4E 45 2C 20 55 |NICATION LINE, U|
00000F10: 53 45 44 20 46 4F 52 20 43 4F 4E 4E 45 43 54 49 |SED FOR CONNECTI|
00000F20: 4E 47 20 54 45 52 4D 49 4E 41 4C 53 20 54 4F 0D |NG TERMINALS TO.|
00000F30: 43 4F 4D 50 55 54 45 52 53 2E 20 20 D3 54 41 4E |COMPUTERS. .TAN|
00000F40: 44 41 52 44 53 20 46 4F 52 20 54 48 49 53 20 4D |DARDS FOR THIS M|
00000F50: 45 44 49 55 4D 20 41 52 45 20 41 4C 4D 4F 53 54 |EDIUM ARE ALMOST|
00000F60: 20 55 4E 49 56 45 52 53 41 4C 4C 59 20 46 4F 4C | UNIVERSALLY FOL|
00000F70: 4C 4F 57 45 44 20 2D 0D 43 4F 4E 4E 45 43 54 4F |LOWED -.CONNECTO|
00000F80: 52 53 2C 20 56 4F 4C 54 41 47 45 53 2C 20 41 4E |RS, VOLTAGES, AN|
00000F90: 44 20 53 49 47 4E 41 4C 53 20 28 C5 C9 C1 20 D2 |D SIGNALS (... .|
00000FA0: D3 2D 32 33 32 2D C3 29 2C 20 43 48 41 52 41 43 |.-232-.), CHARAC|
00000FB0: 54 45 52 20 45 4E 43 4F 44 49 4E 47 20 28 C1 D3 |TER ENCODING (..|
00000FC0: C3 C9 C9 2C 0D C1 CE D3 C9 20 D8 33 2E 34 2D 31 |...,..... .3.4-1|
00000FD0: 39 37 37 29 2C 20 41 4E 44 20 42 49 54 20 54 52 |977), AND BIT TR|
00000FE0: 41 4E 53 4D 49 53 53 49 4F 4E 20 53 45 51 55 45 |ANSMISSION SEQUE|
00000FF0: 4E 43 45 20 28 C1 CE D3 C9 20 D8 33 2E 31 35 2D |NCE (.... .3.15-|
00001000: 31 39 37 36 29 2E 20 20 D3 45 52 49 41 4C 0D 43 |1976). .ERIAL.C|
00001010: 4F 4E 4E 45 43 54 49 4F 4E 53 20 43 41 4E 20 42 |ONNECTIONS CAN B|
00001020: 45 20 4D 41 44 45 20 49 4E 20 4D 41 4E 59 20 57 |E MADE IN MANY W|
00001030: 41 59 53 3A 20 44 45 44 49 43 41 54 45 44 20 4C |AYS: DEDICATED L|
00001040: 4F 43 41 4C 20 4C 49 4E 45 53 20 28 22 4E 55 4C |OCAL LINES ("NUL|
00001050: 4C 20 4D 4F 44 45 4D 22 0D 43 41 42 4C 45 53 29 |L MODEM".CABLES)|
00001060: 2C 20 4C 45 41 53 45 44 20 54 45 4C 45 50 48 4F |, LEASED TELEPHO|
00001070: 4E 45 20 43 49 52 43 55 49 54 53 2C 20 44 49 41 |NE CIRCUITS, DIA|
00001080: 4C 55 50 20 43 4F 4E 4E 45 43 54 49 4F 4E 53 2E |LUP CONNECTIONS.|
00001090: 20 20 C4 49 41 4C 55 50 20 43 4F 4E 4E 45 43 54 | .IALUP CONNECT|
000010A0: 49 4F 4E 53 0D 43 41 4E 20 42 45 20 49 4E 49 54 |IONS.CAN BE INIT|
000010B0: 49 41 54 45 44 20 4D 41 4E 55 41 4C 4C 59 20 46 |IATED MANUALLY F|
000010C0: 52 4F 4D 20 54 48 45 20 48 4F 4D 45 20 4F 52 20 |ROM THE HOME OR |
000010D0: 4F 46 46 49 43 45 20 55 53 49 4E 47 20 41 4E 20 |OFFICE USING AN |
000010E0: 49 4E 45 58 50 45 4E 53 49 56 45 20 41 43 4F 55 |INEXPENSIVE ACOU|
000010F0: 53 54 49 43 0D 43 4F 55 50 4C 45 52 2C 20 4F 52 |STIC.COUPLER, OR|
00001100: 20 41 55 54 4F 4D 41 54 49 43 41 4C 4C 59 20 46 | AUTOMATICALLY F|
00001110: 52 4F 4D 20 4F 4E 45 20 43 4F 4D 50 55 54 45 52 |ROM ONE COMPUTER|
00001120: 20 54 4F 20 41 4E 4F 54 48 45 52 20 55 53 49 4E | TO ANOTHER USIN|
00001130: 47 20 41 20 50 52 4F 47 52 41 4D 4D 41 42 4C 45 |G A PROGRAMMABLE|
00001140: 0D 44 49 41 4C 4F 55 54 20 4D 45 43 48 41 4E 49 |.DIALOUT MECHANI|
00001150: 53 4D 2E 20 20 D4 48 45 20 41 53 59 4E 43 48 52 |SM. .HE ASYNCHR|
00001160: 4F 4E 4F 55 53 20 53 45 52 49 41 4C 20 4C 49 4E |ONOUS SERIAL LIN|
00001170: 45 20 4F 46 46 45 52 53 20 54 48 45 20 4F 52 44 |E OFFERS THE ORD|
00001180: 49 4E 41 52 59 20 55 53 45 52 20 41 0D 48 49 47 |INARY USER A.HIG|
00001190: 48 20 44 45 47 52 45 45 20 4F 46 20 43 4F 4E 56 |H DEGREE OF CONV|
000011A0: 45 4E 49 45 4E 43 45 20 41 4E 44 20 43 4F 4E 54 |ENIENCE AND CONT|
000011B0: 52 4F 4C 20 49 4E 20 45 53 54 41 42 4C 49 53 48 |ROL IN ESTABLISH|
000011C0: 49 4E 47 20 49 4E 54 45 52 53 59 53 54 45 4D 20 |ING INTERSYSTEM |
000011D0: 43 4F 4E 4E 45 43 54 49 4F 4E 53 2C 0D 41 54 20 |CONNECTIONS,.AT |
000011E0: 52 45 4C 41 54 49 56 45 4C 59 20 4C 4F 57 20 43 |RELATIVELY LOW C|
000011F0: 4F 53 54 2E 0D 0D CF 4E 43 45 20 54 57 4F 20 43 |OST....NCE TWO C|
00001200: 4F 4D 50 55 54 45 52 53 20 41 52 45 20 43 4F 4E |OMPUTERS ARE CON|
00001210: 4E 45 43 54 45 44 20 57 49 54 48 20 41 20 53 45 |NECTED WITH A SE|
00001220: 52 49 41 4C 20 4C 49 4E 45 2C 20 49 4E 46 4F 52 |RIAL LINE, INFOR|
00001230: 4D 41 54 49 4F 4E 20 43 41 4E 20 42 45 20 54 52 |MATION CAN BE TR|
00001240: 41 4E 53 2D 0D 46 45 52 52 45 44 20 46 52 4F 4D |ANS-.FERRED FROM|
00001250: 20 4F 4E 45 20 4D 41 43 48 49 4E 45 20 54 4F 20 | ONE MACHINE TO |
00001260: 54 48 45 20 4F 54 48 45 52 2C 20 50 52 4F 56 49 |THE OTHER, PROVI|
00001270: 44 45 44 20 4F 4E 45 20 53 49 44 45 20 43 41 4E |DED ONE SIDE CAN|
00001280: 20 42 45 20 49 4E 53 54 52 55 43 54 45 44 20 54 | BE INSTRUCTED T|
00001290: 4F 0D 53 45 4E 44 20 54 48 45 20 49 4E 46 4F 52 |O.SEND THE INFOR|
000012A0: 4D 41 54 49 4F 4E 20 41 4E 44 20 54 48 45 20 4F |MATION AND THE O|
000012B0: 54 48 45 52 20 54 4F 20 52 45 43 45 49 56 45 20 |THER TO RECEIVE |
000012C0: 49 54 2E 20 20 C2 55 54 20 52 49 47 48 54 20 41 |IT. .UT RIGHT A|
000012D0: 57 41 59 2C 20 53 45 56 45 52 41 4C 0D 49 4D 50 |WAY, SEVERAL.IMP|
000012E0: 4F 52 54 41 4E 54 20 46 41 43 54 4F 52 53 20 43 |ORTANT FACTORS C|
000012F0: 4F 4D 45 20 49 4E 54 4F 20 50 4C 41 59 3A 0D 0D |OME INTO PLAY:..|
00001300: CE 4F 49 53 45 20 2D 2D 20 C9 54 20 49 53 20 52 |.OISE -- .T IS R|
00001310: 41 52 45 4C 59 20 53 41 46 45 20 54 4F 20 41 53 |ARELY SAFE TO AS|
00001320: 53 55 4D 45 20 54 48 41 54 20 54 48 45 52 45 20 |SUME THAT THERE |
00001330: 57 49 4C 4C 20 42 45 20 4E 4F 20 45 4C 45 43 54 |WILL BE NO ELECT|
00001340: 52 49 43 41 4C 20 49 4E 54 45 52 2D 0D 46 45 52 |RICAL INTER-.FER|
00001350: 45 4E 43 45 20 4F 4E 20 41 20 4C 49 4E 45 3B 20 |ENCE ON A LINE; |
00001360: 41 4E 59 20 4C 4F 4E 47 20 4F 52 20 53 57 49 54 |ANY LONG OR SWIT|
00001370: 43 48 45 44 20 44 41 54 41 20 43 4F 4D 4D 55 4E |CHED DATA COMMUN|
00001380: 49 43 41 54 49 4F 4E 20 4C 49 4E 45 20 57 49 4C |ICATION LINE WIL|
00001390: 4C 20 48 41 56 45 0D 4F 43 43 41 53 49 4F 4E 41 |L HAVE.OCCASIONA|
000013A0: 4C 20 49 4E 54 45 52 46 45 52 45 4E 43 45 2C 20 |L INTERFERENCE, |
000013B0: 4F 52 20 4E 4F 49 53 45 2C 20 57 48 49 43 48 20 |OR NOISE, WHICH |
000013C0: 54 59 50 49 43 41 4C 4C 59 20 52 45 53 55 4C 54 |TYPICALLY RESULT|
000013D0: 53 20 49 4E 20 47 41 52 42 4C 45 44 20 4F 52 20 |S IN GARBLED OR |
000013E0: 45 58 54 52 41 0D 43 48 41 52 41 43 54 45 52 53 |EXTRA.CHARACTERS|
000013F0: 2E 20 CE 4F 49 53 45 20 43 4F 52 52 55 50 54 53 |. .OISE CORRUPTS|
00001400: 20 44 41 54 41 2C 20 50 45 52 48 41 50 53 20 49 | DATA, PERHAPS I|
00001410: 4E 20 53 55 42 54 4C 45 20 57 41 59 53 20 54 48 |N SUBTLE WAYS TH|
00001420: 41 54 20 4D 49 47 48 54 20 4E 4F 54 20 42 45 0D |AT MIGHT NOT BE.|
00001430: 4E 4F 54 49 43 45 44 20 55 4E 54 49 4C 20 49 54 |NOTICED UNTIL IT|
00001440: 27 53 20 54 4F 4F 20 4C 41 54 45 2E 0D 0D D3 59 |'S TOO LATE....Y|
00001450: 4E 43 48 52 4F 4E 49 5A 41 54 49 4F 4E 20 2D 2D |NCHRONIZATION --|
00001460: 20 C4 41 54 41 20 4D 55 53 54 20 4E 4F 54 20 43 | .ATA MUST NOT C|
00001470: 4F 4D 45 20 49 4E 20 46 41 53 54 45 52 20 54 48 |OME IN FASTER TH|
00001480: 41 4E 20 54 48 45 20 52 45 43 45 49 56 49 4E 47 |AN THE RECEIVING|
00001490: 20 4D 41 43 48 49 4E 45 20 43 41 4E 0D 48 41 4E | MACHINE CAN.HAN|
000014A0: 44 4C 45 20 49 54 2E 20 C1 4C 54 48 4F 55 47 48 |DLE IT. .LTHOUGH|
000014B0: 20 4C 49 4E 45 20 53 50 45 45 44 53 20 41 54 20 | LINE SPEEDS AT |
000014C0: 54 48 45 20 54 57 4F 20 45 4E 44 53 20 4F 46 20 |THE TWO ENDS OF |
000014D0: 54 48 45 20 43 4F 4E 4E 45 43 54 49 4F 4E 20 4D |THE CONNECTION M|
000014E0: 41 59 20 4D 41 54 43 48 2C 0D 54 48 45 20 52 45 |AY MATCH,.THE RE|
000014F0: 43 45 49 56 49 4E 47 20 4D 41 43 48 49 4E 45 20 |CEIVING MACHINE |
00001500: 4D 49 47 48 54 20 4E 4F 54 20 42 45 20 41 42 4C |MIGHT NOT BE ABL|
00001510: 45 20 54 4F 20 50 52 4F 43 45 53 53 20 41 20 53 |E TO PROCESS A S|
00001520: 54 45 41 44 59 20 53 54 52 45 41 4D 20 4F 46 20 |TEADY STREAM OF |
00001530: 49 4E 50 55 54 20 41 54 0D 54 48 41 54 20 53 50 |INPUT AT.THAT SP|
00001540: 45 45 44 2E 20 C9 54 53 20 43 45 4E 54 52 41 4C |EED. .TS CENTRAL|
00001550: 20 50 52 4F 43 45 53 53 4F 52 20 4D 41 59 20 42 | PROCESSOR MAY B|
00001560: 45 20 54 4F 4F 20 53 4C 4F 57 20 4F 52 20 54 4F |E TOO SLOW OR TO|
00001570: 4F 20 48 45 41 56 49 4C 59 20 4C 4F 41 44 45 44 |O HEAVILY LOADED|
00001580: 2C 20 4F 52 20 49 54 53 0D 42 55 46 46 45 52 53 |, OR ITS.BUFFERS|
00001590: 20 54 4F 4F 20 46 55 4C 4C 20 4F 52 20 54 4F 4F | TOO FULL OR TOO|
000015A0: 20 53 4D 41 4C 4C 2E 20 D4 48 45 20 54 59 50 49 | SMALL. .HE TYPI|
000015B0: 43 41 4C 20 53 59 4D 50 54 4F 4D 20 4F 46 20 41 |CAL SYMPTOM OF A|
000015C0: 20 53 59 4E 43 48 52 4F 4E 49 5A 41 54 49 4F 4E | SYNCHRONIZATION|
000015D0: 20 50 52 4F 42 4C 45 4D 0D 49 53 20 4C 4F 53 54 | PROBLEM.IS LOST|
000015E0: 20 44 41 54 41 3B 20 4D 4F 53 54 20 4F 50 45 52 | DATA; MOST OPER|
000015F0: 41 54 49 4E 47 20 53 59 53 54 45 4D 53 20 57 49 |ATING SYSTEMS WI|
00001600: 4C 4C 20 53 49 4D 50 4C 59 20 44 49 53 43 41 52 |LL SIMPLY DISCAR|
00001610: 44 20 49 4E 43 4F 4D 49 4E 47 20 44 41 54 41 20 |D INCOMING DATA |
00001620: 54 48 45 59 20 41 52 45 0D 4E 4F 54 20 50 52 45 |THEY ARE.NOT PRE|
00001630: 50 41 52 45 44 20 54 4F 20 52 45 43 45 49 56 45 |PARED TO RECEIVE|
00001640: 2E 0D 0D CC 49 4E 45 20 CF 55 54 41 47 45 53 20 |....INE .UTAGES |
00001650: 2D 2D 20 C1 20 4C 49 4E 45 20 4D 41 59 20 53 54 |-- . LINE MAY ST|
00001660: 4F 50 20 57 4F 52 4B 49 4E 47 20 46 4F 52 20 53 |OP WORKING FOR S|
00001670: 48 4F 52 54 20 50 45 52 49 4F 44 53 20 42 45 43 |HORT PERIODS BEC|
00001680: 41 55 53 45 20 4F 46 20 41 20 46 41 55 4C 54 59 |AUSE OF A FAULTY|
00001690: 0D 43 4F 4E 4E 45 43 54 4F 52 2C 20 4C 4F 53 53 |.CONNECTOR, LOSS|
000016A0: 20 4F 46 20 50 4F 57 45 52 2C 20 4F 52 20 53 49 | OF POWER, OR SI|
000016B0: 4D 49 4C 41 52 20 52 45 41 53 4F 4E 2E 20 CF 4E |MILAR REASON. .N|
000016C0: 20 44 49 41 4C 55 50 20 4F 52 20 53 57 49 54 43 | DIALUP OR SWITC|
000016D0: 48 45 44 20 43 4F 4E 4E 45 43 54 49 4F 4E 53 2C |HED CONNECTIONS,|
000016E0: 0D 53 55 43 48 20 49 4E 54 45 52 4D 49 54 54 45 |.SUCH INTERMITTE|
000016F0: 4E 54 20 46 41 49 4C 55 52 45 53 20 57 49 4C 4C |NT FAILURES WILL|
00001700: 20 43 41 55 53 45 20 43 41 52 52 49 45 52 20 54 | CAUSE CARRIER T|
00001710: 4F 20 44 52 4F 50 20 41 4E 44 20 54 48 45 20 43 |O DROP AND THE C|
00001720: 4F 4E 4E 45 43 54 49 4F 4E 20 54 4F 20 42 45 0D |ONNECTION TO BE.|
00001730: 43 4C 4F 53 45 44 2C 20 42 55 54 20 46 4F 52 20 |CLOSED, BUT FOR |
00001740: 41 4E 59 20 43 4F 4E 4E 45 43 54 49 4F 4E 20 49 |ANY CONNECTION I|
00001750: 4E 20 57 48 49 43 48 20 54 48 45 20 43 41 52 52 |N WHICH THE CARR|
00001760: 49 45 52 20 53 49 47 4E 41 4C 20 49 53 20 4E 4F |IER SIGNAL IS NO|
00001770: 54 20 55 53 45 44 2C 20 54 48 45 0D 53 59 4D 50 |T USED, THE.SYMP|
00001780: 54 4F 4D 20 57 49 4C 4C 20 42 45 20 4C 4F 53 54 |TOM WILL BE LOST|
00001790: 20 44 41 54 41 2E 0D 0D CF 54 48 45 52 20 43 4F | DATA....THER CO|
000017A0: 4D 4D 55 4E 49 43 41 54 49 4F 4E 20 4D 45 44 49 |MMUNICATION MEDI|
000017B0: 41 2C 20 53 55 43 48 20 41 53 20 54 48 45 20 50 |A, SUCH AS THE P|
000017C0: 41 52 41 4C 4C 45 4C 20 44 41 54 41 20 42 55 53 |ARALLEL DATA BUS|
000017D0: 2C 20 48 41 56 45 20 53 41 46 45 47 55 41 52 44 |, HAVE SAFEGUARD|
000017E0: 53 20 42 55 49 4C 54 0D 49 4E 20 54 4F 20 50 52 |S BUILT.IN TO PR|
000017F0: 45 56 45 4E 54 20 4F 52 20 4D 49 4E 49 4D 49 5A |EVENT OR MINIMIZ|
00001800: 45 20 54 48 45 53 45 20 45 46 46 45 43 54 53 2E |E THESE EFFECTS.|
00001810: 20 20 C6 4F 52 20 49 4E 53 54 41 4E 43 45 2C 20 | .OR INSTANCE, |
00001820: 44 49 53 54 41 4E 43 45 53 20 4D 41 59 20 42 45 |DISTANCES MAY BE|
00001830: 0D 53 54 52 49 43 54 4C 59 20 4C 49 4D 49 54 45 |.STRICTLY LIMITE|
00001840: 44 2C 20 54 48 45 20 45 4E 56 49 52 4F 4E 4D 45 |D, THE ENVIRONME|
00001850: 4E 54 20 43 4F 4E 54 52 4F 4C 4C 45 44 3B 20 53 |NT CONTROLLED; S|
00001860: 50 45 43 49 41 4C 20 53 49 47 4E 41 4C 53 20 4D |PECIAL SIGNALS M|
00001870: 41 59 20 42 45 20 41 56 41 49 4C 41 42 4C 45 0D |AY BE AVAILABLE.|
00001880: 46 4F 52 20 53 59 4E 43 48 52 4F 4E 49 5A 41 54 |FOR SYNCHRONIZAT|
00001890: 49 4F 4E 2C 20 41 4E 44 20 53 4F 20 46 4F 52 54 |ION, AND SO FORT|
000018A0: 48 2E 20 20 D4 48 45 20 53 45 52 49 41 4C 20 54 |H. .HE SERIAL T|
000018B0: 45 4C 45 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E |ELECOMMUNICATION|
000018C0: 20 4C 49 4E 45 20 50 52 4F 56 49 44 45 53 0D 4E | LINE PROVIDES.N|
000018D0: 4F 20 53 55 43 48 20 53 41 46 45 47 55 41 52 44 |O SUCH SAFEGUARD|
000018E0: 53 2C 20 41 4E 44 20 57 45 20 4D 55 53 54 20 54 |S, AND WE MUST T|
000018F0: 48 45 52 45 46 4F 52 45 20 52 45 47 41 52 44 20 |HEREFORE REGARD |
00001900: 49 54 20 41 53 20 41 4E 20 49 4E 54 52 49 4E 53 |IT AS AN INTRINS|
00001910: 49 43 41 4C 4C 59 0D 55 4E 52 45 4C 49 41 42 4C |ICALLY.UNRELIABL|
00001920: 45 20 4D 45 44 49 55 4D 2E 0D 0D 0D C7 45 54 54 |E MEDIUM.....ETT|
00001930: 49 4E 47 20 D2 45 4C 49 41 42 4C 45 20 C3 4F 4D |ING .ELIABLE .OM|
00001940: 4D 55 4E 49 43 41 54 49 4F 4E 20 4F 56 45 52 20 |MUNICATION OVER |
00001950: 41 4E 20 D5 4E 52 45 4C 49 41 42 4C 45 20 CD 45 |AN .NRELIABLE .E|
00001960: 44 49 55 4D 0D 0D D4 4F 20 44 45 54 45 52 4D 49 |DIUM...O DETERMI|
00001970: 4E 45 20 57 48 45 54 48 45 52 20 44 41 54 41 20 |NE WHETHER DATA |
00001980: 48 41 53 20 42 45 45 4E 20 54 52 41 4E 53 4D 49 |HAS BEEN TRANSMI|
00001990: 54 54 45 44 20 42 45 54 57 45 45 4E 20 54 57 4F |TTED BETWEEN TWO|
000019A0: 20 4D 41 43 48 49 4E 45 53 20 43 4F 52 52 45 43 | MACHINES CORREC|
000019B0: 54 4C 59 0D 41 4E 44 20 43 4F 4D 50 4C 45 54 45 |TLY.AND COMPLETE|
000019C0: 4C 59 2C 20 54 48 45 20 54 57 4F 20 4D 41 43 48 |LY, THE TWO MACH|
000019D0: 49 4E 45 53 20 43 41 4E 20 43 4F 4D 50 41 52 45 |INES CAN COMPARE|
000019E0: 20 54 48 45 20 44 41 54 41 20 42 45 46 4F 52 45 | THE DATA BEFORE|
000019F0: 20 41 4E 44 20 41 46 54 45 52 20 54 52 41 4E 53 | AND AFTER TRANS|
00001A00: 2D 0D 4D 49 53 53 49 4F 4E 2E 20 C1 20 53 43 48 |-.MISSION. . SCH|
00001A10: 45 4D 45 20 54 48 41 54 20 49 53 20 43 4F 4D 4D |EME THAT IS COMM|
00001A20: 4F 4E 4C 59 20 55 53 45 44 20 46 4F 52 20 46 49 |ONLY USED FOR FI|
00001A30: 4C 45 20 54 52 41 4E 53 46 45 52 20 45 4D 50 4C |LE TRANSFER EMPL|
00001A40: 4F 59 53 20 43 4F 4F 50 45 52 41 54 49 4E 47 0D |OYS COOPERATING.|
00001A50: 50 52 4F 47 52 41 4D 53 20 52 55 4E 4E 49 4E 47 |PROGRAMS RUNNING|
00001A60: 20 53 49 4D 55 4C 54 41 4E 45 4F 55 53 4C 59 20 | SIMULTANEOUSLY |
00001A70: 4F 4E 20 45 41 43 48 20 4D 41 43 48 49 4E 45 2C |ON EACH MACHINE,|
00001A80: 20 43 4F 4D 4D 55 4E 49 43 41 54 49 4E 47 20 49 | COMMUNICATING I|
00001A90: 4E 20 41 20 57 45 4C 4C 2D 0D 44 45 46 49 4E 45 |N A WELL-.DEFINE|
00001AA0: 44 2C 20 43 4F 4E 43 49 53 45 20 4C 41 4E 47 55 |D, CONCISE LANGU|
00001AB0: 41 47 45 2E 20 20 D4 48 45 20 53 45 4E 44 49 4E |AGE. .HE SENDIN|
00001AC0: 47 20 50 52 4F 47 52 41 4D 20 44 49 56 49 44 45 |G PROGRAM DIVIDE|
00001AD0: 53 20 4F 55 54 42 4F 55 4E 44 20 44 41 54 41 20 |S OUTBOUND DATA |
00001AE0: 49 4E 54 4F 0D 44 49 53 43 52 45 54 45 20 50 49 |INTO.DISCRETE PI|
00001AF0: 45 43 45 53 2C 20 41 44 44 49 4E 47 20 54 4F 20 |ECES, ADDING TO |
00001B00: 45 41 43 48 20 50 49 45 43 45 20 53 50 45 43 49 |EACH PIECE SPECI|
00001B10: 41 4C 20 49 4E 46 4F 52 4D 41 54 49 4F 4E 20 44 |AL INFORMATION D|
00001B20: 45 53 43 52 49 42 49 4E 47 20 54 48 45 20 44 41 |ESCRIBING THE DA|
00001B30: 54 41 0D 46 4F 52 20 54 48 45 20 52 45 43 45 49 |TA.FOR THE RECEI|
00001B40: 56 49 4E 47 20 50 52 4F 47 52 41 4D 2E 20 D4 48 |VING PROGRAM. .H|
00001B50: 45 20 52 45 53 55 4C 54 20 49 53 20 43 41 4C 4C |E RESULT IS CALL|
00001B60: 45 44 20 41 20 22 50 41 43 4B 45 54 22 2E 20 20 |ED A "PACKET". |
00001B70: D4 48 45 20 52 45 43 45 49 56 45 52 0D 53 45 50 |.HE RECEIVER.SEP|
00001B80: 41 52 41 54 45 53 20 54 48 45 20 44 45 53 43 52 |ARATES THE DESCR|
00001B90: 49 50 54 49 4F 4E 20 46 52 4F 4D 20 54 48 45 20 |IPTION FROM THE |
00001BA0: 44 41 54 41 20 41 4E 44 20 44 45 54 45 52 4D 49 |DATA AND DETERMI|
00001BB0: 4E 45 53 20 57 48 45 54 48 45 52 20 54 48 45 59 |NES WHETHER THEY|
00001BC0: 20 53 54 49 4C 4C 0D 4D 41 54 43 48 2E 20 C9 46 | STILL.MATCH. .F|
00001BD0: 20 53 4F 2C 20 54 48 45 20 50 41 43 4B 45 54 20 | SO, THE PACKET |
00001BE0: 49 53 20 41 43 4B 4E 4F 57 4C 45 44 47 45 44 20 |IS ACKNOWLEDGED |
00001BF0: 41 4E 44 20 54 48 45 20 54 52 41 4E 53 46 45 52 |AND THE TRANSFER|
00001C00: 20 50 52 4F 43 45 45 44 53 2E 20 C9 46 20 4E 4F | PROCEEDS. .F NO|
00001C10: 54 2C 0D 54 48 45 20 50 41 43 4B 45 54 20 49 53 |T,.THE PACKET IS|
00001C20: 20 22 4E 45 47 41 54 49 56 45 4C 59 20 41 43 4B | "NEGATIVELY ACK|
00001C30: 4E 4F 57 4C 45 44 47 45 44 22 20 41 4E 44 20 54 |NOWLEDGED" AND T|
00001C40: 48 45 20 53 45 4E 44 45 52 20 52 45 54 52 41 4E |HE SENDER RETRAN|
00001C50: 53 4D 49 54 53 20 49 54 3B 20 54 48 49 53 0D 50 |SMITS IT; THIS.P|
00001C60: 52 4F 43 45 44 55 52 45 20 52 45 50 45 41 54 53 |ROCEDURE REPEATS|
00001C70: 20 46 4F 52 20 45 41 43 48 20 50 41 43 4B 45 54 | FOR EACH PACKET|
00001C80: 20 55 4E 54 49 4C 20 49 54 20 49 53 20 52 45 43 | UNTIL IT IS REC|
00001C90: 45 49 56 45 44 20 43 4F 52 52 45 43 54 4C 59 2E |EIVED CORRECTLY.|
00001CA0: 0D 0D D4 48 45 20 50 52 4F 43 45 53 53 20 49 53 |...HE PROCESS IS|
00001CB0: 20 43 41 4C 4C 45 44 20 41 20 43 4F 4D 4D 55 4E | CALLED A COMMUN|
00001CC0: 49 43 41 54 49 4F 4E 20 50 52 4F 54 4F 43 4F 4C |ICATION PROTOCOL|
00001CD0: 20 2D 20 41 20 53 45 54 20 4F 46 20 52 55 4C 45 | - A SET OF RULE|
00001CE0: 53 20 46 4F 52 20 46 4F 52 4D 49 4E 47 0D 41 4E |S FOR FORMING.AN|
00001CF0: 44 20 54 52 41 4E 53 4D 49 54 54 49 4E 47 20 50 |D TRANSMITTING P|
00001D00: 41 43 4B 45 54 53 2C 20 43 41 52 52 49 45 44 20 |ACKETS, CARRIED |
00001D10: 4F 55 54 20 42 59 20 50 52 4F 47 52 41 4D 53 20 |OUT BY PROGRAMS |
00001D20: 54 48 41 54 20 45 4D 42 4F 44 59 20 54 48 4F 53 |THAT EMBODY THOS|
00001D30: 45 20 52 55 4C 45 53 2E 0D D0 52 4F 54 4F 43 4F |E RULES...ROTOCO|
00001D40: 4C 53 20 56 41 52 59 20 49 4E 20 43 4F 4D 50 4C |LS VARY IN COMPL|
00001D50: 45 58 49 54 59 3B 20 4F 55 52 20 50 52 45 46 45 |EXITY; OUR PREFE|
00001D60: 52 45 4E 43 45 20 57 41 53 20 46 4F 52 20 41 20 |RENCE WAS FOR A |
00001D70: 53 49 4D 50 4C 45 20 41 50 50 52 4F 41 43 48 20 |SIMPLE APPROACH |
00001D80: 54 48 41 54 0D 43 4F 55 4C 44 20 42 45 20 52 45 |THAT.COULD BE RE|
00001D90: 41 4C 49 5A 45 44 20 49 4E 20 41 4C 4D 4F 53 54 |ALIZED IN ALMOST|
00001DA0: 20 41 4E 59 20 4C 41 4E 47 55 41 47 45 20 4F 4E | ANY LANGUAGE ON|
00001DB0: 20 41 4C 4D 4F 53 54 20 41 4E 59 20 43 4F 4D 50 | ALMOST ANY COMP|
00001DC0: 55 54 45 52 20 42 59 20 41 20 50 52 4F 47 52 41 |UTER BY A PROGRA|
00001DD0: 4D 4D 45 52 0D 4F 46 20 4D 4F 44 45 52 41 54 45 |MMER.OF MODERATE|
00001DE0: 20 53 4B 49 4C 4C 2C 20 41 4C 4C 4F 57 49 4E 47 | SKILL, ALLOWING|
00001DF0: 20 54 48 45 20 50 52 4F 54 4F 43 4F 4C 20 54 4F | THE PROTOCOL TO|
00001E00: 20 42 45 20 41 44 41 50 54 45 44 20 45 41 53 49 | BE ADAPTED EASI|
00001E10: 4C 59 20 54 4F 20 4E 45 57 20 53 59 53 54 45 4D |LY TO NEW SYSTEM|
00001E20: 53 2E 0D 0D 0D 0D C1 43 43 4F 4D 4D 4F 44 41 54 |S......CCOMMODAT|
00001E30: 49 4E 47 20 C4 49 56 45 52 53 45 20 D3 59 53 54 |ING .IVERSE .YST|
00001E40: 45 4D 53 0D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D |EMS.============|
00001E50: 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D |================|
00001E60: 3D 0D 0D CD 4F 53 54 20 53 59 53 54 45 4D 53 20 |=...OST SYSTEMS |
00001E70: 41 47 52 45 45 20 48 4F 57 20 54 4F 20 43 4F 4D |AGREE HOW TO COM|
00001E80: 4D 55 4E 49 43 41 54 45 20 41 54 20 54 48 45 20 |MUNICATE AT THE |
00001E90: 4C 4F 57 45 53 54 20 4C 45 56 45 4C 53 20 2D 20 |LOWEST LEVELS - |
00001EA0: 54 48 45 20 C5 C9 C1 20 D2 D3 2D 32 33 32 2D C3 |THE ... ..-232-.|
00001EB0: 0D 41 53 59 4E 43 48 52 4F 4E 4F 55 53 20 43 4F |.ASYNCHRONOUS CO|
00001EC0: 4D 4D 55 4E 49 43 41 54 49 4F 4E 20 4C 49 4E 45 |MMUNICATION LINE|
00001ED0: 20 41 4E 44 20 54 48 45 20 C1 D3 C3 C9 C9 20 43 | AND THE ..... C|
00001EE0: 48 41 52 41 43 54 45 52 20 53 45 54 20 2D 20 42 |HARACTER SET - B|
00001EF0: 55 54 20 54 48 45 52 45 20 49 53 0D 52 41 52 45 |UT THERE IS.RARE|
00001F00: 4C 59 20 41 47 52 45 45 4D 45 4E 54 20 42 45 59 |LY AGREEMENT BEY|
00001F10: 4F 4E 44 20 54 48 41 54 2E 20 20 D4 4F 20 41 56 |OND THAT. .O AV|
00001F20: 4F 49 44 20 41 20 44 45 53 49 47 4E 20 54 48 41 |OID A DESIGN THA|
00001F30: 54 20 4D 49 47 48 54 20 4C 4F 43 4B 20 4F 55 54 |T MIGHT LOCK OUT|
00001F40: 20 53 4F 4D 45 20 4B 49 4E 44 53 0D 4F 46 20 53 | SOME KINDS.OF S|
00001F50: 59 53 54 45 4D 53 2C 20 57 45 20 4D 55 53 54 20 |YSTEMS, WE MUST |
00001F60: 43 4F 4E 53 49 44 45 52 20 43 45 52 54 41 49 4E |CONSIDER CERTAIN|
00001F70: 20 49 4D 50 4F 52 54 41 4E 54 20 57 41 59 53 20 | IMPORTANT WAYS |
00001F80: 49 4E 20 57 48 49 43 48 20 53 59 53 54 45 4D 53 |IN WHICH SYSTEMS|
00001F90: 20 43 41 4E 0D 44 49 46 46 45 52 2E 0D 0D CD 41 | CAN.DIFFER....A|
00001FA0: 49 4E 46 52 41 4D 45 53 20 56 53 20 CD 49 43 52 |INFRAMES VS .ICR|
00001FB0: 4F 53 0D 0D C1 20 44 49 53 54 49 4E 43 54 49 4F |OS... DISTINCTIO|
00001FC0: 4E 20 4D 55 53 54 20 46 49 52 53 54 20 42 45 20 |N MUST FIRST BE |
00001FD0: 4D 41 44 45 20 42 45 54 57 45 45 4E 20 4D 49 43 |MADE BETWEEN MIC|
00001FE0: 52 4F 53 20 41 4E 44 20 4D 41 49 4E 46 52 41 4D |ROS AND MAINFRAM|
00001FF0: 45 53 2E 20 20 D4 48 45 53 45 20 54 45 52 4D 53 |ES. .HESE TERMS|
00002000: 0D 41 52 45 20 4E 4F 54 20 55 53 45 44 20 50 45 |.ARE NOT USED PE|
00002010: 52 4A 4F 52 41 54 49 56 45 4C 59 3B 20 41 20 22 |RJORATIVELY; A "|
00002020: 4D 49 43 52 4F 22 20 43 4F 55 4C 44 20 42 45 20 |MICRO" COULD BE |
00002030: 41 20 50 4F 57 45 52 46 55 4C 20 57 4F 52 4B 53 |A POWERFUL WORKS|
00002040: 54 41 54 49 4F 4E 2C 20 41 4E 44 20 41 0D 22 4D |TATION, AND A."M|
00002050: 41 49 4E 46 52 41 4D 45 22 20 43 4F 55 4C 44 20 |AINFRAME" COULD |
00002060: 42 45 20 41 20 53 4D 41 4C 4C 20 4D 49 4E 49 43 |BE A SMALL MINIC|
00002070: 4F 4D 50 55 54 45 52 2E 20 20 C6 4F 52 20 4F 55 |OMPUTER. .OR OU|
00002080: 52 20 50 55 52 50 4F 53 45 53 2C 20 41 20 4D 49 |R PURPOSES, A MI|
00002090: 43 52 4F 20 49 53 20 41 4E 59 0D 53 49 4E 47 4C |CRO IS ANY.SINGL|
000020A0: 45 2D 55 53 45 52 20 53 59 53 54 45 4D 20 49 4E |E-USER SYSTEM IN|
000020B0: 20 57 48 49 43 48 20 54 48 45 20 53 45 52 49 41 | WHICH THE SERIA|
000020C0: 4C 20 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E 20 |L COMMUNICATION |
000020D0: 50 4F 52 54 20 49 53 20 53 54 52 49 43 54 4C 59 |PORT IS STRICTLY|
000020E0: 20 41 4E 0D 45 58 54 45 52 4E 41 4C 20 44 45 56 | AN.EXTERNAL DEV|
000020F0: 49 43 45 2E 20 20 C1 20 4D 41 49 4E 46 52 41 4D |ICE. . MAINFRAM|
00002100: 45 20 49 53 20 41 4E 59 20 53 59 53 54 45 4D 20 |E IS ANY SYSTEM |
00002110: 57 48 49 43 48 20 49 53 20 22 48 4F 53 54 22 20 |WHICH IS "HOST" |
00002120: 54 4F 20 4D 55 4C 54 49 50 4C 45 0D 53 49 4D 55 |TO MULTIPLE.SIMU|
00002130: 4C 54 41 4E 45 4F 55 53 20 54 45 52 4D 49 4E 41 |LTANEOUS TERMINA|
00002140: 4C 20 55 53 45 52 53 2C 20 57 48 4F 20 4C 4F 47 |L USERS, WHO LOG|
00002150: 20 49 4E 20 54 4F 20 22 4A 4F 42 53 22 2C 20 41 | IN TO "JOBS", A|
00002160: 4E 44 20 57 48 45 52 45 20 41 20 55 53 45 52 27 |ND WHERE A USER'|
00002170: 53 20 54 45 52 4D 49 4E 41 4C 0D 49 53 20 54 48 |S TERMINAL.IS TH|
00002180: 45 20 4A 4F 42 27 53 20 22 43 4F 4E 54 52 4F 4C |E JOB'S "CONTROL|
00002190: 4C 49 4E 47 20 54 45 52 4D 49 4E 41 4C 22 2E 20 |LING TERMINAL". |
000021A0: 20 D3 4F 4D 45 20 4D 41 49 4E 46 52 41 4D 45 20 | .OME MAINFRAME |
000021B0: 53 59 53 54 45 4D 53 20 41 4C 4C 4F 57 20 55 53 |SYSTEMS ALLOW US|
000021C0: 45 52 53 20 54 4F 0D 22 41 53 53 49 47 4E 22 20 |ERS TO."ASSIGN" |
000021D0: 41 4E 4F 54 48 45 52 20 54 45 52 4D 49 4E 41 4C |ANOTHER TERMINAL|
000021E0: 20 4C 49 4E 45 20 4F 4E 20 54 48 45 20 53 41 4D | LINE ON THE SAM|
000021F0: 45 20 4D 41 43 48 49 4E 45 20 41 53 20 41 4E 20 |E MACHINE AS AN |
00002200: 45 58 54 45 52 4E 41 4C 20 49 4E 50 55 54 2F 4F |EXTERNAL INPUT/O|
00002210: 55 54 50 55 54 0D 44 45 56 49 43 45 2E 0D CD 41 |UTPUT.DEVICE...A|
00002220: 49 4E 46 52 41 4D 45 20 4F 50 45 52 41 54 49 4E |INFRAME OPERATIN|
00002230: 47 20 53 59 53 54 45 4D 20 54 45 52 4D 49 4E 41 |G SYSTEM TERMINA|
00002240: 4C 20 44 52 49 56 45 52 53 20 55 53 55 41 4C 4C |L DRIVERS USUALL|
00002250: 59 20 54 52 45 41 54 20 41 20 4A 4F 42 27 53 20 |Y TREAT A JOB'S |
00002260: 43 4F 4E 54 52 4F 4C 4C 49 4E 47 0D 54 45 52 4D |CONTROLLING.TERM|
00002270: 49 4E 41 4C 20 53 50 45 43 49 41 4C 4C 59 2E 20 |INAL SPECIALLY. |
00002280: 20 C6 55 4C 4C 20 44 55 50 4C 45 58 20 53 59 53 | .ULL DUPLEX SYS|
00002290: 54 45 4D 53 20 45 43 48 4F 20 49 4E 43 4F 4D 49 |TEMS ECHO INCOMI|
000022A0: 4E 47 20 43 48 41 52 41 43 54 45 52 53 20 4F 4E |NG CHARACTERS ON|
000022B0: 20 54 48 45 0D 43 4F 4E 54 52 4F 4C 4C 49 4E 47 | THE.CONTROLLING|
000022C0: 20 54 45 52 4D 49 4E 41 4C 2C 20 42 55 54 20 4E | TERMINAL, BUT N|
000022D0: 4F 54 20 4F 4E 20 41 4E 20 41 53 53 49 47 4E 45 |OT ON AN ASSIGNE|
000022E0: 44 20 4C 49 4E 45 2E 20 20 D3 59 53 54 45 4D 20 |D LINE. .YSTEM |
000022F0: 43 4F 4D 4D 41 4E 44 20 49 4E 54 45 52 50 52 45 |COMMAND INTERPRE|
00002300: 54 45 52 53 0D 4F 52 20 55 53 45 52 20 50 52 4F |TERS.OR USER PRO|
00002310: 43 45 53 53 45 53 20 4D 49 47 48 54 20 54 41 4B |CESSES MIGHT TAK|
00002320: 45 20 53 50 45 43 49 41 4C 20 41 43 54 49 4F 4E |E SPECIAL ACTION|
00002330: 20 4F 4E 20 43 45 52 54 41 49 4E 20 43 48 41 52 | ON CERTAIN CHAR|
00002340: 41 43 54 45 52 53 20 4F 4E 20 54 48 45 0D 43 4F |ACTERS ON THE.CO|
00002350: 4E 54 52 4F 4C 4C 49 4E 47 20 4C 49 4E 45 2C 20 |NTROLLING LINE, |
00002360: 42 55 54 20 4E 4F 54 20 4F 4E 20 41 4E 20 41 53 |BUT NOT ON AN AS|
00002370: 53 49 47 4E 45 44 20 4C 49 4E 45 20 28 46 4F 52 |SIGNED LINE (FOR|
00002380: 20 49 4E 53 54 41 4E 43 45 2C 20 43 4F 4E 54 52 | INSTANCE, CONTR|
00002390: 4F 4C 2D C3 20 55 4E 44 45 52 0D C3 D0 2F CD 20 |OL-. UNDER.../. |
000023A0: 4F 52 20 4D 4F 53 54 20 C4 C5 C3 20 4F 50 45 52 |OR MOST ... OPER|
000023B0: 41 54 49 4E 47 20 53 59 53 54 45 4D 53 29 2E 20 |ATING SYSTEMS). |
000023C0: 20 CD 45 53 53 41 47 45 53 20 53 45 4E 54 20 54 | .ESSAGES SENT T|
000023D0: 4F 20 41 20 4A 4F 42 27 53 20 43 4F 4E 54 52 4F |O A JOB'S CONTRO|
000023E0: 4C 4C 49 4E 47 0D 54 45 52 4D 49 4E 41 4C 20 46 |LLING.TERMINAL F|
000023F0: 52 4F 4D 20 4F 54 48 45 52 20 4A 4F 42 53 20 43 |ROM OTHER JOBS C|
00002400: 4F 55 4C 44 20 49 4E 54 45 52 46 45 52 45 20 57 |OULD INTERFERE W|
00002410: 49 54 48 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E |ITH TRANSMISSION|
00002420: 20 4F 46 20 44 41 54 41 2E 20 20 D4 48 45 0D 41 | OF DATA. .HE.A|
00002430: 42 49 4C 49 54 59 20 4F 46 20 41 20 53 59 53 54 |BILITY OF A SYST|
00002440: 45 4D 20 54 4F 20 54 45 53 54 20 46 4F 52 20 54 |EM TO TEST FOR T|
00002450: 48 45 20 41 56 41 49 4C 41 42 49 4C 49 54 59 20 |HE AVAILABILITY |
00002460: 4F 46 20 49 4E 50 55 54 20 4F 4E 20 41 20 53 45 |OF INPUT ON A SE|
00002470: 52 49 41 4C 20 4C 49 4E 45 0D 4D 49 47 48 54 20 |RIAL LINE.MIGHT |
00002480: 44 45 50 45 4E 44 20 4F 4E 20 57 48 45 54 48 45 |DEPEND ON WHETHE|
00002490: 52 20 54 48 45 20 4C 49 4E 45 20 49 53 20 54 48 |R THE LINE IS TH|
000024A0: 45 20 4A 4F 42 27 53 20 43 4F 4E 54 52 4F 4C 4C |E JOB'S CONTROLL|
000024B0: 49 4E 47 20 54 45 52 4D 49 4E 41 4C 20 4F 52 20 |ING TERMINAL OR |
000024C0: 41 4E 0D 41 53 53 49 47 4E 45 44 20 44 45 56 49 |AN.ASSIGNED DEVI|
000024D0: 43 45 3B 20 C3 D0 2F CD 20 41 4E 44 20 C9 C2 CD |CE; ../. AND ...|
000024E0: 20 D6 CD 2F 33 37 30 20 41 52 45 20 45 58 41 4D | ../370 ARE EXAM|
000024F0: 50 4C 45 53 20 4F 46 20 53 55 43 48 20 53 59 53 |PLES OF SUCH SYS|
00002500: 54 45 4D 53 2E 20 C3 D0 2F CD 20 43 41 4E 0D 54 |TEMS. ../. CAN.T|
00002510: 45 53 54 20 46 4F 52 20 44 41 54 41 20 4F 4E 4C |EST FOR DATA ONL|
00002520: 59 20 41 54 20 54 48 45 20 43 4F 4E 53 4F 4C 45 |Y AT THE CONSOLE|
00002530: 2C 20 D6 CD 20 43 41 4E 20 54 45 53 54 20 41 4E |, .. CAN TEST AN|
00002540: 59 57 48 45 52 45 20 42 55 54 20 54 48 45 20 43 |YWHERE BUT THE C|
00002550: 4F 4E 53 4F 4C 45 2E 0D 0D CF 55 54 50 55 54 20 |ONSOLE....UTPUT |
00002560: 54 4F 20 41 20 4A 4F 42 27 53 20 43 4F 4E 54 52 |TO A JOB'S CONTR|
00002570: 4F 4C 4C 49 4E 47 20 54 45 52 4D 49 4E 41 4C 20 |OLLING TERMINAL |
00002580: 4D 41 59 20 42 45 20 52 45 46 4F 52 4D 41 54 54 |MAY BE REFORMATT|
00002590: 45 44 20 42 59 20 54 48 45 20 4F 50 45 52 41 54 |ED BY THE OPERAT|
000025A0: 49 4E 47 0D 53 59 53 54 45 4D 3A 20 43 4F 4E 54 |ING.SYSTEM: CONT|
000025B0: 52 4F 4C 20 43 48 41 52 41 43 54 45 52 53 20 4D |ROL CHARACTERS M|
000025C0: 41 59 20 42 45 20 54 52 41 4E 53 4C 41 54 45 44 |AY BE TRANSLATED|
000025D0: 20 54 4F 20 50 52 49 4E 54 41 42 4C 45 20 45 51 | TO PRINTABLE EQ|
000025E0: 55 49 56 41 4C 45 4E 54 53 2C 20 4C 4F 57 45 52 |UIVALENTS, LOWER|
000025F0: 0D 43 41 53 45 20 4C 45 54 54 45 52 53 20 53 50 |.CASE LETTERS SP|
00002600: 45 43 49 41 4C 4C 59 20 46 4C 41 47 47 45 44 20 |ECIALLY FLAGGED |
00002610: 4F 52 20 54 52 41 4E 53 4C 41 54 45 44 20 54 4F |OR TRANSLATED TO|
00002620: 20 55 50 50 45 52 20 43 41 53 45 20 28 4F 52 20 | UPPER CASE (OR |
00002630: 56 49 43 45 20 56 45 52 53 41 29 2C 0D 54 41 42 |VICE VERSA),.TAB|
00002640: 53 20 45 58 50 41 4E 44 45 44 20 54 4F 20 53 50 |S EXPANDED TO SP|
00002650: 41 43 45 53 2E 20 20 C9 4E 20 41 44 44 49 54 49 |ACES. .N ADDITI|
00002660: 4F 4E 2C 20 42 41 53 45 44 20 4F 4E 20 54 48 45 |ON, BASED ON THE|
00002670: 20 54 45 52 4D 49 4E 41 4C 27 53 20 44 45 43 4C | TERMINAL'S DECL|
00002680: 41 52 45 44 20 22 57 49 44 54 48 22 0D 41 4E 44 |ARED "WIDTH".AND|
00002690: 20 22 4C 45 4E 47 54 48 22 2C 20 4C 4F 4E 47 20 | "LENGTH", LONG |
000026A0: 4C 49 4E 45 53 20 4D 49 47 48 54 20 42 45 20 22 |LINES MIGHT BE "|
000026B0: 57 52 41 50 50 45 44 20 41 52 4F 55 4E 44 22 20 |WRAPPED AROUND" |
000026C0: 4F 52 20 54 52 55 4E 43 41 54 45 44 2C 20 46 4F |OR TRUNCATED, FO|
000026D0: 52 4D 46 45 45 44 53 0D 54 52 41 4E 53 4C 41 54 |RMFEEDS.TRANSLAT|
000026E0: 45 44 20 54 4F 20 41 20 53 45 52 49 45 53 20 4F |ED TO A SERIES O|
000026F0: 46 20 4C 49 4E 45 46 45 45 44 53 2C 20 41 4E 44 |F LINEFEEDS, AND|
00002700: 20 54 48 45 20 53 59 53 54 45 4D 20 4D 41 59 20 | THE SYSTEM MAY |
00002710: 57 41 4E 54 20 54 4F 20 50 41 55 53 45 20 41 54 |WANT TO PAUSE AT|
00002720: 20 54 48 45 0D 45 4E 44 20 4F 46 20 45 41 43 48 | THE.END OF EACH|
00002730: 20 53 43 52 45 45 4E 46 55 4C 20 4F 46 20 4F 55 | SCREENFUL OF OU|
00002740: 54 50 55 54 2E 20 20 C9 4E 50 55 54 20 46 52 4F |TPUT. .NPUT FRO|
00002750: 4D 20 41 20 4A 4F 42 27 53 20 43 4F 4E 54 52 4F |M A JOB'S CONTRO|
00002760: 4C 4C 49 4E 47 20 54 45 52 4D 49 4E 41 4C 20 4D |LLING TERMINAL M|
00002770: 41 59 0D 41 4C 53 4F 20 42 45 20 48 41 4E 44 4C |AY.ALSO BE HANDL|
00002780: 45 44 20 53 50 45 43 49 41 4C 4C 59 3A 20 4C 4F |ED SPECIALLY: LO|
00002790: 57 45 52 20 43 41 53 45 20 4C 45 54 54 45 52 53 |WER CASE LETTERS|
000027A0: 20 4D 41 59 20 42 45 20 43 4F 4E 56 45 52 54 45 | MAY BE CONVERTE|
000027B0: 44 20 54 4F 20 55 50 50 45 52 20 43 41 53 45 2C |D TO UPPER CASE,|
000027C0: 0D 4C 49 4E 45 46 45 45 44 20 4D 41 59 20 42 45 |.LINEFEED MAY BE|
000027D0: 20 53 55 50 50 4C 49 45 44 20 57 48 45 4E 20 43 | SUPPLIED WHEN C|
000027E0: 41 52 52 49 41 47 45 20 52 45 54 55 52 4E 20 49 |ARRIAGE RETURN I|
000027F0: 53 20 54 59 50 45 44 2C 20 43 4F 4E 54 52 4F 4C |S TYPED, CONTROL|
00002800: 20 43 48 41 52 41 43 54 45 52 53 20 4D 41 59 0D | CHARACTERS MAY.|
00002810: 49 4E 56 4F 4B 45 20 53 50 45 43 49 41 4C 20 46 |INVOKE SPECIAL F|
00002820: 55 4E 43 54 49 4F 4E 53 20 4C 49 4B 45 20 4C 49 |UNCTIONS LIKE LI|
00002830: 4E 45 20 45 44 49 54 49 4E 47 20 4F 52 20 50 52 |NE EDITING OR PR|
00002840: 4F 47 52 41 4D 20 49 4E 54 45 52 52 55 50 54 49 |OGRAM INTERRUPTI|
00002850: 4F 4E 2E 0D D4 48 45 20 C4 C5 C3 D3 D9 D3 D4 C5 |ON...HE ........|
00002860: CD 2D 32 30 20 49 53 20 41 4E 20 45 58 41 4D 50 |.-20 IS AN EXAMP|
00002870: 4C 45 20 4F 46 20 41 20 43 4F 4D 50 55 54 45 52 |LE OF A COMPUTER|
00002880: 20 57 48 45 52 45 20 41 4E 59 20 4F 46 20 54 48 | WHERE ANY OF TH|
00002890: 45 53 45 20 4D 49 47 48 54 20 48 41 50 50 45 4E |ESE MIGHT HAPPEN|
000028A0: 2E 0D D4 48 45 20 4D 4F 52 41 4C 20 48 45 52 45 |...HE MORAL HERE|
000028B0: 20 49 53 20 54 48 41 54 20 43 41 52 45 20 4D 55 | IS THAT CARE MU|
000028C0: 53 54 20 42 45 20 54 41 4B 45 4E 20 54 4F 20 44 |ST BE TAKEN TO D|
000028D0: 49 53 41 42 4C 45 20 53 50 45 43 49 41 4C 20 48 |ISABLE SPECIAL H|
000028E0: 41 4E 44 4C 49 4E 47 20 4F 46 20 41 0D 4D 41 49 |ANDLING OF A.MAI|
000028F0: 4E 46 52 41 4D 45 20 4A 4F 42 27 53 20 43 4F 4E |NFRAME JOB'S CON|
00002900: 54 52 4F 4C 4C 49 4E 47 20 54 45 52 4D 49 4E 41 |TROLLING TERMINA|
00002910: 4C 20 57 48 45 4E 20 49 54 20 49 53 20 54 4F 20 |L WHEN IT IS TO |
00002920: 42 45 20 41 20 56 45 48 49 43 4C 45 20 46 4F 52 |BE A VEHICLE FOR|
00002930: 20 49 4E 54 45 52 2D 0D 50 52 4F 43 45 53 53 4F | INTER-.PROCESSO|
00002940: 52 20 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E 2E |R COMMUNICATION.|
00002950: 20 20 C2 55 54 20 53 4F 4D 45 20 53 59 53 54 45 | .UT SOME SYSTE|
00002960: 4D 53 20 53 49 4D 50 4C 59 20 44 4F 20 4E 4F 54 |MS SIMPLY DO NOT|
00002970: 20 41 4C 4C 4F 57 20 43 45 52 54 41 49 4E 20 4F | ALLOW CERTAIN O|
00002980: 46 20 54 48 45 53 45 0D 46 45 41 54 55 52 45 53 |F THESE.FEATURES|
00002990: 20 54 4F 20 42 45 20 44 49 53 41 42 4C 45 44 2C | TO BE DISABLED,|
000029A0: 20 53 4F 20 46 49 4C 45 20 54 52 41 4E 53 46 45 | SO FILE TRANSFE|
000029B0: 52 20 50 52 4F 54 4F 43 4F 4C 53 20 4D 55 53 54 |R PROTOCOLS MUST|
000029C0: 20 42 45 20 44 45 53 49 47 4E 45 44 20 41 52 4F | BE DESIGNED ARO|
000029D0: 55 4E 44 0D 54 48 45 4D 2E 0D 0D CC 49 4E 45 20 |UND.THEM....INE |
000029E0: C1 43 43 45 53 53 0D 0D CC 49 4E 45 20 41 43 43 |.CCESS...INE ACC|
000029F0: 45 53 53 20 43 41 4E 20 42 45 20 45 49 54 48 45 |ESS CAN BE EITHE|
00002A00: 52 20 46 55 4C 4C 20 4F 52 20 48 41 4C 46 20 44 |R FULL OR HALF D|
00002A10: 55 50 4C 45 58 2E 20 C9 46 20 46 55 4C 4C 20 44 |UPLEX. .F FULL D|
00002A20: 55 50 4C 45 58 2C 20 54 52 41 4E 53 4D 49 53 53 |UPLEX, TRANSMISS|
00002A30: 49 4F 4E 20 43 41 4E 0D 4F 43 43 55 52 20 49 4E |ION CAN.OCCUR IN|
00002A40: 20 42 4F 54 48 20 44 49 52 45 43 54 49 4F 4E 53 | BOTH DIRECTIONS|
00002A50: 20 41 54 20 4F 4E 43 45 2E 20 C9 46 20 48 41 4C | AT ONCE. .F HAL|
00002A60: 46 20 44 55 50 4C 45 58 2C 20 54 48 45 20 54 57 |F DUPLEX, THE TW|
00002A70: 4F 20 53 49 44 45 53 20 4D 55 53 54 20 54 41 4B |O SIDES MUST TAK|
00002A80: 45 20 54 55 52 4E 53 0D 53 45 4E 44 49 4E 47 2C |E TURNS.SENDING,|
00002A90: 20 45 41 43 48 20 53 49 47 4E 41 4C 49 4E 47 20 | EACH SIGNALING |
00002AA0: 54 48 45 20 4F 54 48 45 52 20 57 48 45 4E 20 54 |THE OTHER WHEN T|
00002AB0: 48 45 20 4C 49 4E 45 20 49 53 20 46 52 45 45 3B |HE LINE IS FREE;|
00002AC0: 20 44 41 54 41 20 53 45 4E 54 20 4F 55 54 20 4F | DATA SENT OUT O|
00002AD0: 46 20 54 55 52 4E 0D 49 53 20 44 49 53 43 41 52 |F TURN.IS DISCAR|
00002AE0: 44 45 44 2C 20 4F 52 20 49 54 20 43 41 4E 20 43 |DED, OR IT CAN C|
00002AF0: 41 55 53 45 20 41 20 42 52 45 41 4B 20 49 4E 20 |AUSE A BREAK IN |
00002B00: 53 59 4E 43 48 52 4F 4E 49 5A 41 54 49 4F 4E 2E |SYNCHRONIZATION.|
00002B10: 20 20 CF 4E 20 4D 41 49 4E 46 52 41 4D 45 53 2C | .N MAINFRAMES,|
00002B20: 20 54 48 45 0D 48 4F 53 54 20 45 43 48 4F 45 53 | THE.HOST ECHOES|
00002B30: 20 43 48 41 52 41 43 54 45 52 53 20 54 59 50 45 | CHARACTERS TYPE|
00002B40: 44 20 41 54 20 54 48 45 20 54 45 52 4D 49 4E 41 |D AT THE TERMINA|
00002B50: 4C 20 49 4E 20 46 55 4C 4C 20 44 55 50 4C 45 58 |L IN FULL DUPLEX|
00002B60: 2C 20 42 55 54 20 4E 4F 54 20 49 4E 20 48 41 4C |, BUT NOT IN HAL|
00002B70: 46 0D 44 55 50 4C 45 58 2E 20 CE 41 54 55 52 41 |F.DUPLEX. .ATURA|
00002B80: 4C 4C 59 2C 20 45 43 48 4F 49 4E 47 20 49 53 20 |LLY, ECHOING IS |
00002B90: 55 4E 44 45 53 49 52 41 42 4C 45 20 44 55 52 49 |UNDESIRABLE DURI|
00002BA0: 4E 47 20 46 49 4C 45 20 54 52 41 4E 53 46 45 52 |NG FILE TRANSFER|
00002BB0: 2E 20 C6 55 4C 4C 20 44 55 50 4C 45 58 0D 53 59 |. .ULL DUPLEX.SY|
00002BC0: 53 54 45 4D 53 20 43 41 4E 20 55 53 55 41 4C 4C |STEMS CAN USUALL|
00002BD0: 59 20 41 43 43 4F 4D 4D 4F 44 41 54 45 20 48 41 |Y ACCOMMODATE HA|
00002BE0: 4C 46 20 44 55 50 4C 45 58 20 43 4F 4D 4D 55 4E |LF DUPLEX COMMUN|
00002BF0: 49 43 41 54 49 4F 4E 2C 20 42 55 54 20 4E 4F 54 |ICATION, BUT NOT|
00002C00: 20 56 49 43 45 20 56 45 52 53 41 2E 0D C9 C2 CD | VICE VERSA.....|
00002C10: 20 4D 41 49 4E 46 52 41 4D 45 53 20 41 52 45 20 | MAINFRAMES ARE |
00002C20: 54 48 45 20 4D 4F 53 54 20 50 52 45 56 41 4C 45 |THE MOST PREVALE|
00002C30: 4E 54 20 48 41 4C 46 20 44 55 50 4C 45 58 20 53 |NT HALF DUPLEX S|
00002C40: 59 53 54 45 4D 53 2E 0D 0D C2 55 46 46 45 52 49 |YSTEMS....UFFERI|
00002C50: 4E 47 20 41 4E 44 20 C6 4C 4F 57 20 C3 4F 4E 54 |NG AND .LOW .ONT|
00002C60: 52 4F 4C 0D 0D D3 4F 4D 45 20 53 59 53 54 45 4D |ROL...OME SYSTEM|
00002C70: 53 20 43 41 4E 4E 4F 54 20 48 41 4E 44 4C 45 20 |S CANNOT HANDLE |
00002C80: 53 55 53 54 41 49 4E 45 44 20 42 55 52 53 54 53 |SUSTAINED BURSTS|
00002C90: 20 4F 46 20 49 4E 50 55 54 20 4F 4E 20 41 20 54 | OF INPUT ON A T|
00002CA0: 45 4C 45 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E |ELECOMMUNICATION|
00002CB0: 53 0D 4C 49 4E 45 3B 20 54 48 45 20 49 4E 50 55 |S.LINE; THE INPU|
00002CC0: 54 20 42 55 46 46 45 52 20 43 41 4E 20 46 49 4C |T BUFFER CAN FIL|
00002CD0: 4C 20 55 50 20 46 41 53 54 45 52 20 54 48 41 4E |L UP FASTER THAN|
00002CE0: 20 49 54 20 43 41 4E 20 42 45 20 45 4D 50 54 49 | IT CAN BE EMPTI|
00002CF0: 45 44 2C 20 45 53 50 45 43 49 41 4C 4C 59 20 41 |ED, ESPECIALLY A|
00002D00: 54 0D 48 49 47 48 20 4C 49 4E 45 20 53 50 45 45 |T.HIGH LINE SPEE|
00002D10: 44 53 2E 20 20 D3 4F 4D 45 20 53 59 53 54 45 4D |DS. .OME SYSTEM|
00002D20: 53 20 41 54 54 45 4D 50 54 20 54 4F 20 42 55 46 |S ATTEMPT TO BUF|
00002D30: 46 45 52 20 22 54 59 50 45 41 48 45 41 44 22 20 |FER "TYPEAHEAD" |
00002D40: 28 55 4E 52 45 51 55 45 53 54 45 44 0D 49 4E 50 |(UNREQUESTED.INP|
00002D50: 55 54 29 2C 20 57 48 49 4C 45 20 4F 54 48 45 52 |UT), WHILE OTHER|
00002D60: 53 20 44 49 53 43 41 52 44 20 49 54 2E 20 20 D4 |S DISCARD IT. .|
00002D70: 48 4F 53 45 20 54 48 41 54 20 42 55 46 46 45 52 |HOSE THAT BUFFER|
00002D80: 20 54 59 50 45 41 48 45 41 44 20 4D 41 59 20 4F | TYPEAHEAD MAY O|
00002D90: 52 20 4D 41 59 20 4E 4F 54 0D 50 52 4F 56 49 44 |R MAY NOT.PROVID|
00002DA0: 45 20 41 20 4D 45 43 48 41 4E 49 53 4D 20 54 4F |E A MECHANISM TO|
00002DB0: 20 54 45 53 54 20 4F 52 20 43 4C 45 41 52 20 54 | TEST OR CLEAR T|
00002DC0: 48 45 20 42 55 46 46 45 52 2E 0D D3 59 53 54 45 |HE BUFFER...YSTE|
00002DD0: 4D 53 20 4D 41 59 20 54 52 59 20 54 4F 20 52 45 |MS MAY TRY TO RE|
00002DE0: 47 55 4C 41 54 45 20 48 4F 57 20 46 41 53 54 20 |GULATE HOW FAST |
00002DF0: 43 48 41 52 41 43 54 45 52 53 20 43 4F 4D 45 20 |CHARACTERS COME |
00002E00: 49 4E 20 55 53 49 4E 47 20 41 20 46 4C 4F 57 20 |IN USING A FLOW |
00002E10: 43 4F 4E 54 52 4F 4C 0D 4D 45 43 48 41 4E 49 53 |CONTROL.MECHANIS|
00002E20: 4D 2C 20 45 49 54 48 45 52 20 49 4E 20 54 48 45 |M, EITHER IN THE|
00002E30: 20 44 41 54 41 20 53 54 52 45 41 4D 20 28 D8 CF | DATA STREAM (..|
00002E40: CE 2F D8 CF C6 C6 29 20 4F 52 20 49 4E 20 50 41 |./....) OR IN PA|
00002E50: 52 41 4C 4C 45 4C 20 54 4F 20 49 54 20 28 4D 4F |RALLEL TO IT (MO|
00002E60: 44 45 4D 0D 43 4F 4E 54 52 4F 4C 20 53 49 47 4E |DEM.CONTROL SIGN|
00002E70: 41 4C 53 29 2C 20 42 55 54 20 4E 4F 20 54 57 4F |ALS), BUT NO TWO|
00002E80: 20 53 59 53 54 45 4D 53 20 43 41 4E 20 42 45 20 | SYSTEMS CAN BE |
00002E90: 41 53 53 55 4D 45 44 20 54 4F 20 48 4F 4E 4F 52 |ASSUMED TO HONOR|
00002EA0: 20 54 48 45 20 53 41 4D 45 0D 43 4F 4E 56 45 4E | THE SAME.CONVEN|
00002EB0: 54 49 4F 4E 53 20 46 4F 52 20 46 4C 4F 57 20 43 |TIONS FOR FLOW C|
00002EC0: 4F 4E 54 52 4F 4C 2C 20 4F 52 20 54 4F 20 44 4F |ONTROL, OR TO DO|
00002ED0: 20 49 54 20 41 54 20 41 4C 4C 2E 0D C5 56 45 4E | IT AT ALL...VEN|
00002EE0: 20 57 48 45 4E 20 46 4C 4F 57 20 43 4F 4E 54 52 | WHEN FLOW CONTR|
00002EF0: 4F 4C 20 49 53 20 42 45 49 4E 47 20 44 4F 4E 45 |OL IS BEING DONE|
00002F00: 2C 20 54 48 45 20 43 4F 4E 54 52 4F 4C 20 53 49 |, THE CONTROL SI|
00002F10: 47 4E 41 4C 53 20 54 48 45 4D 53 45 4C 56 45 53 |GNALS THEMSELVES|
00002F20: 20 41 52 45 0D 53 55 42 4A 45 43 54 20 54 4F 20 | ARE.SUBJECT TO |
00002F30: 4E 4F 49 53 45 20 43 4F 52 52 55 50 54 49 4F 4E |NOISE CORRUPTION|
00002F40: 2E 20 CF 55 52 20 45 58 50 45 52 49 4D 45 4E 54 |. .UR EXPERIMENT|
00002F50: 53 20 57 49 54 48 20 53 45 56 45 52 41 4C 20 48 |S WITH SEVERAL H|
00002F60: 4F 53 54 20 43 4F 4D 50 55 54 45 52 53 0D 52 45 |OST COMPUTERS.RE|
00002F70: 56 45 41 4C 45 44 20 54 48 41 54 20 41 20 42 55 |VEALED THAT A BU|
00002F80: 52 53 54 20 4F 46 20 4D 4F 52 45 20 54 48 41 4E |RST OF MORE THAN|
00002F90: 20 41 42 4F 55 54 20 41 20 4C 49 4E 45 27 53 20 | ABOUT A LINE'S |
00002FA0: 57 4F 52 54 48 20 4F 46 20 43 48 41 52 41 43 54 |WORTH OF CHARACT|
00002FB0: 45 52 53 0D 28 36 30 2D 31 30 30 20 43 48 41 52 |ERS.(60-100 CHAR|
00002FC0: 41 43 54 45 52 53 29 20 49 4E 54 4F 20 41 20 54 |ACTERS) INTO A T|
00002FD0: 45 52 4D 49 4E 41 4C 20 50 4F 52 54 20 41 54 20 |ERMINAL PORT AT |
00002FE0: 4D 4F 44 45 52 41 54 45 20 53 50 45 45 44 20 43 |MODERATE SPEED C|
00002FF0: 4F 55 4C 44 20 52 45 53 55 4C 54 20 49 4E 0D 4C |OULD RESULT IN.L|
00003000: 4F 53 53 20 4F 46 20 44 41 54 41 20 2D 20 4F 52 |OSS OF DATA - OR|
00003010: 20 57 4F 52 53 45 20 2D 20 4F 4E 20 53 4F 4D 45 | WORSE - ON SOME|
00003020: 20 48 4F 53 54 53 2E 20 20 C6 4F 52 20 49 4E 53 | HOSTS. .OR INS|
00003030: 54 41 4E 43 45 2C 20 54 48 45 20 43 4F 4D 4D 55 |TANCE, THE COMMU|
00003040: 4E 49 43 41 54 49 4F 4E 53 0D 46 52 4F 4E 54 20 |NICATIONS.FRONT |
00003050: 45 4E 44 20 4F 46 20 54 48 45 20 C4 C5 C3 D3 D9 |END OF THE .....|
00003060: D3 D4 C5 CD 2D 32 30 36 30 20 49 53 20 44 45 53 |....-2060 IS DES|
00003070: 49 47 4E 45 44 20 4F 4E 20 54 48 45 20 53 54 41 |IGNED ON THE STA|
00003080: 54 49 53 54 49 43 41 4C 20 41 53 53 55 4D 50 54 |TISTICAL ASSUMPT|
00003090: 49 4F 4E 20 54 48 41 54 0D 41 4C 4C 20 54 45 52 |ION THAT.ALL TER|
000030A0: 4D 49 4E 41 4C 20 49 4E 50 55 54 20 43 4F 4D 45 |MINAL INPUT COME|
000030B0: 53 20 46 52 4F 4D 20 48 55 4D 41 4E 20 46 49 4E |S FROM HUMAN FIN|
000030C0: 47 45 52 53 2C 20 41 4E 44 20 49 54 20 43 41 4E |GERS, AND IT CAN|
000030D0: 4E 4F 54 20 41 4C 4C 4F 43 41 54 45 20 42 55 46 |NOT ALLOCATE BUF|
000030E0: 46 45 52 53 0D 46 41 53 54 20 45 4E 4F 55 47 48 |FERS.FAST ENOUGH|
000030F0: 20 57 48 45 4E 20 54 48 49 53 20 41 53 53 55 4D | WHEN THIS ASSUM|
00003100: 50 54 49 4F 4E 20 49 53 20 56 49 4F 4C 41 54 45 |PTION IS VIOLATE|
00003110: 44 20 42 59 20 53 45 4E 44 49 4E 47 20 43 4F 4E |D BY SENDING CON|
00003120: 54 49 4E 55 4F 55 53 20 44 41 54 41 0D 53 49 4D |TINUOUS DATA.SIM|
00003130: 55 4C 54 41 4E 45 4F 55 53 4C 59 20 46 52 4F 4D |ULTANEOUSLY FROM|
00003140: 20 53 45 56 45 52 41 4C 20 4D 49 43 52 4F 43 4F | SEVERAL MICROCO|
00003150: 4D 50 55 54 45 52 53 20 41 54 54 41 43 48 45 44 |MPUTERS ATTACHED|
00003160: 20 54 4F 20 54 45 52 4D 49 4E 41 4C 20 50 4F 52 | TO TERMINAL POR|
00003170: 54 53 2E 0D 0D C3 48 41 52 41 43 54 45 52 20 C9 |TS....HARACTER .|
00003180: 4E 54 45 52 50 52 45 54 41 54 49 4F 4E 0D 0D D3 |NTERPRETATION...|
00003190: 59 53 54 45 4D 53 20 43 41 4E 20 44 49 46 46 45 |YSTEMS CAN DIFFE|
000031A0: 52 20 49 4E 20 48 4F 57 20 54 48 45 59 20 49 4E |R IN HOW THEY IN|
000031B0: 54 45 52 50 52 45 54 20 43 48 41 52 41 43 54 45 |TERPRET CHARACTE|
000031C0: 52 53 20 54 48 41 54 20 41 52 52 49 56 45 20 41 |RS THAT ARRIVE A|
000031D0: 54 20 54 48 45 20 54 45 52 4D 49 4E 41 4C 0D 50 |T THE TERMINAL.P|
000031E0: 4F 52 54 2E 20 C1 20 48 4F 53 54 20 43 41 4E 20 |ORT. . HOST CAN |
000031F0: 41 43 43 45 50 54 20 53 4F 4D 45 20 43 48 41 52 |ACCEPT SOME CHAR|
00003200: 41 43 54 45 52 53 20 41 53 20 53 45 4E 54 2C 20 |ACTERS AS SENT, |
00003210: 49 47 4E 4F 52 45 20 4F 54 48 45 52 53 2C 20 54 |IGNORE OTHERS, T|
00003220: 52 41 4E 53 4C 41 54 45 0D 4F 54 48 45 52 53 2C |RANSLATE.OTHERS,|
00003230: 20 54 41 4B 45 20 53 50 45 43 49 41 4C 20 41 43 | TAKE SPECIAL AC|
00003240: 54 49 4F 4E 20 4F 4E 20 4F 54 48 45 52 53 2E 20 |TION ON OTHERS. |
00003250: 20 C3 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E 53 20 | .OMMUNICATIONS |
00003260: 46 52 4F 4E 54 20 45 4E 44 53 20 4F 52 20 4D 55 |FRONT ENDS OR MU|
00003270: 4C 54 49 2D 0D 50 4C 45 58 45 52 53 20 4D 49 47 |LTI-.PLEXERS MIG|
00003280: 48 54 20 53 57 41 4C 4C 4F 57 20 43 45 52 54 41 |HT SWALLOW CERTA|
00003290: 49 4E 20 43 48 41 52 41 43 54 45 52 53 20 28 54 |IN CHARACTERS (T|
000032A0: 59 50 49 43 41 4C 4C 59 20 C4 C3 31 2C 20 C4 C3 |YPICALLY ..1, ..|
000032B0: 33 29 20 46 4F 52 20 46 4C 4F 57 20 43 4F 4E 54 |3) FOR FLOW CONT|
000032C0: 52 4F 4C 2C 0D 50 41 44 44 49 4E 47 20 28 CE D5 |ROL,.PADDING (..|
000032D0: CC 20 4F 52 20 C4 C5 CC 29 2C 20 4F 52 20 46 4F |. OR ...), OR FO|
000032E0: 52 20 54 52 41 4E 53 46 45 52 20 4F 46 20 43 4F |R TRANSFER OF CO|
000032F0: 4E 54 52 4F 4C 20 28 22 45 53 43 41 50 45 22 29 |NTROL ("ESCAPE")|
00003300: 2E 20 D4 48 45 20 43 48 41 52 41 43 54 45 52 53 |. .HE CHARACTERS|
00003310: 0D 54 48 41 54 20 54 59 50 49 43 41 4C 4C 59 20 |.THAT TYPICALLY |
00003320: 54 52 49 47 47 45 52 20 53 50 45 43 49 41 4C 20 |TRIGGER SPECIAL |
00003330: 42 45 48 41 56 49 4F 52 20 41 52 45 20 54 48 45 |BEHAVIOR ARE THE|
00003340: 20 C1 D3 C3 C9 C9 20 43 4F 4E 54 52 4F 4C 20 43 | ..... CONTROL C|
00003350: 48 41 52 41 43 54 45 52 53 2C 20 30 2D 33 31 0D |HARACTERS, 0-31.|
00003360: 41 4E 44 20 31 32 37 2E 20 20 C6 4F 52 20 49 4E |AND 127. .OR IN|
00003370: 53 54 41 4E 43 45 2C 20 4F 46 20 54 48 45 53 45 |STANCE, OF THESE|
00003380: 20 33 33 20 43 4F 4E 54 52 4F 4C 20 43 48 41 52 | 33 CONTROL CHAR|
00003390: 41 43 54 45 52 53 2C 20 31 37 20 49 4E 56 4F 4B |ACTERS, 17 INVOK|
000033A0: 45 20 53 50 45 43 49 41 4C 0D 46 55 4E 43 54 49 |E SPECIAL.FUNCTI|
000033B0: 4F 4E 53 20 4F 46 20 4F 55 52 20 C4 C5 C3 D3 D9 |ONS OF OUR .....|
000033C0: D3 D4 C5 CD 2D 32 30 20 43 4F 4D 4D 41 4E 44 20 |....-20 COMMAND |
000033D0: 50 52 4F 43 45 53 53 4F 52 2E 20 20 C8 4F 57 45 |PROCESSOR. .OWE|
000033E0: 56 45 52 2C 20 41 4C 4C 20 48 4F 53 54 53 20 41 |VER, ALL HOSTS A|
000033F0: 4E 44 0D 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E |ND.COMMUNICATION|
00003400: 20 50 52 4F 43 45 53 53 4F 52 53 20 57 45 27 56 | PROCESSORS WE'V|
00003410: 45 20 45 4E 43 4F 55 4E 54 45 52 45 44 20 41 4C |E ENCOUNTERED AL|
00003420: 4C 4F 57 20 41 4E 59 20 22 50 52 49 4E 54 41 42 |LOW ANY "PRINTAB|
00003430: 4C 45 22 20 43 48 41 52 41 43 54 45 52 0D 28 C1 |LE" CHARACTER.(.|
00003440: D3 C3 C9 C9 20 33 32 2D 31 32 36 29 20 54 4F 20 |.... 32-126) TO |
00003450: 52 45 41 43 48 20 41 4E 20 41 50 50 4C 49 43 41 |REACH AN APPLICA|
00003460: 54 49 4F 4E 20 50 52 4F 47 52 41 4D 2C 20 45 56 |TION PROGRAM, EV|
00003470: 45 4E 20 54 48 4F 55 47 48 20 54 48 45 20 43 48 |EN THOUGH THE CH|
00003480: 41 52 41 43 54 45 52 20 4D 41 59 0D 42 45 20 54 |ARACTER MAY.BE T|
00003490: 52 41 4E 53 4C 41 54 45 44 20 54 4F 20 41 20 44 |RANSLATED TO A D|
000034A0: 49 46 46 45 52 45 4E 54 20 45 4E 43 4F 44 49 4E |IFFERENT ENCODIN|
000034B0: 47 2C 20 4C 49 4B 45 20 C5 C2 C3 C4 C9 C3 2C 20 |G, LIKE ......, |
000034C0: 46 4F 52 20 49 4E 54 45 52 4E 41 4C 20 55 53 45 |FOR INTERNAL USE|
000034D0: 2E 0D 0D D3 4F 4D 45 20 4F 50 45 52 41 54 49 4E |....OME OPERATIN|
000034E0: 47 20 53 59 53 54 45 4D 53 20 41 4C 4C 4F 57 20 |G SYSTEMS ALLOW |
000034F0: 41 4E 20 41 50 50 4C 49 43 41 54 49 4F 4E 20 54 |AN APPLICATION T|
00003500: 4F 20 49 4E 50 55 54 20 41 20 43 48 41 52 41 43 |O INPUT A CHARAC|
00003510: 54 45 52 20 41 54 20 41 20 54 49 4D 45 2C 0D 4F |TER AT A TIME,.O|
00003520: 54 48 45 52 53 20 44 45 4C 41 59 20 50 41 53 53 |THERS DELAY PASS|
00003530: 49 4E 47 20 54 48 45 20 43 48 41 52 41 43 54 45 |ING THE CHARACTE|
00003540: 52 53 20 54 4F 20 54 48 45 20 50 52 4F 47 52 41 |RS TO THE PROGRA|
00003550: 4D 20 55 4E 54 49 4C 20 41 20 22 4C 4F 47 49 43 |M UNTIL A "LOGIC|
00003560: 41 4C 20 52 45 43 4F 52 44 22 0D 48 41 53 20 42 |AL RECORD".HAS B|
00003570: 45 45 4E 20 44 45 54 45 43 54 45 44 2C 20 55 53 |EEN DETECTED, US|
00003580: 55 41 4C 4C 59 20 41 20 53 45 51 55 45 4E 43 45 |UALLY A SEQUENCE|
00003590: 20 4F 46 20 43 48 41 52 41 43 54 45 52 53 20 54 | OF CHARACTERS T|
000035A0: 45 52 4D 49 4E 41 54 45 44 20 42 59 20 43 41 52 |ERMINATED BY CAR|
000035B0: 52 49 41 47 45 0D 52 45 54 55 52 4E 20 4F 52 20 |RIAGE.RETURN OR |
000035C0: 4C 49 4E 45 46 45 45 44 2E 20 D3 4F 4D 45 20 52 |LINEFEED. .OME R|
000035D0: 45 43 4F 52 44 20 4F 52 49 45 4E 54 45 44 20 53 |ECORD ORIENTED S|
000035E0: 59 53 54 45 4D 53 20 4C 49 4B 45 20 C9 C2 CD 20 |YSTEMS LIKE ... |
000035F0: D6 CD 2F 33 37 30 20 44 49 53 43 41 52 44 20 54 |../370 DISCARD T|
00003600: 48 45 0D 54 45 52 4D 49 4E 41 54 4F 52 2C 20 4F |HE.TERMINATOR, O|
00003610: 54 48 45 52 53 20 4B 45 45 50 20 49 54 2E 20 C1 |THERS KEEP IT. .|
00003620: 4E 44 20 54 48 45 52 45 20 41 52 45 20 44 49 46 |ND THERE ARE DIF|
00003630: 46 45 52 45 4E 54 20 57 41 59 53 20 4F 46 20 4B |FERENT WAYS OF K|
00003640: 45 45 50 49 4E 47 20 49 54 20 2D 20 D5 CE C9 D8 |EEPING IT - ....|
00003650: 0D 54 52 41 4E 53 4C 41 54 45 53 20 43 41 52 52 |.TRANSLATES CARR|
00003660: 49 41 47 45 20 52 45 54 55 52 4E 20 49 4E 54 4F |IAGE RETURN INTO|
00003670: 20 4C 49 4E 45 46 45 45 44 3B 20 4D 4F 53 54 20 | LINEFEED; MOST |
00003680: C4 C5 C3 20 4F 50 45 52 41 54 49 4E 47 20 53 59 |... OPERATING SY|
00003690: 53 54 45 4D 53 20 4B 45 45 50 20 54 48 45 0D 43 |STEMS KEEP THE.C|
000036A0: 41 52 52 49 41 47 45 20 52 45 54 55 52 4E 20 42 |ARRIAGE RETURN B|
000036B0: 55 54 20 41 4C 53 4F 20 41 44 44 20 41 20 4C 49 |UT ALSO ADD A LI|
000036C0: 4E 45 46 45 45 44 2E 0D 0D D4 49 4D 49 4E 47 20 |NEFEED....IMING |
000036D0: CF 55 54 0D 0D C8 4F 53 54 53 20 4D 41 59 20 4F |.UT...OSTS MAY O|
000036E0: 52 20 4D 41 59 20 4E 4F 54 20 48 41 56 45 20 54 |R MAY NOT HAVE T|
000036F0: 48 45 20 41 42 49 4C 49 54 59 20 54 4F 20 22 54 |HE ABILITY TO "T|
00003700: 49 4D 45 20 4F 55 54 22 2E 20 20 D7 48 45 4E 20 |IME OUT". .HEN |
00003710: 45 58 43 48 41 4E 47 49 4E 47 20 4D 45 53 53 41 |EXCHANGING MESSA|
00003720: 47 45 53 0D 57 49 54 48 20 41 4E 4F 54 48 45 52 |GES.WITH ANOTHER|
00003730: 20 43 4F 4D 50 55 54 45 52 2C 20 49 54 20 49 53 | COMPUTER, IT IS|
00003740: 20 44 45 53 49 52 41 42 4C 45 20 54 4F 20 42 45 | DESIRABLE TO BE|
00003750: 20 41 42 4C 45 20 54 4F 20 49 53 53 55 45 20 41 | ABLE TO ISSUE A|
00003760: 4E 20 49 4E 50 55 54 20 52 45 51 55 45 53 54 0D |N INPUT REQUEST.|
00003770: 57 49 54 48 4F 55 54 20 57 41 49 54 49 4E 47 20 |WITHOUT WAITING |
00003780: 46 4F 52 45 56 45 52 20 53 48 4F 55 4C 44 20 54 |FOREVER SHOULD T|
00003790: 48 45 20 49 4E 43 4F 4D 49 4E 47 20 44 41 54 41 |HE INCOMING DATA|
000037A0: 20 42 45 20 4C 4F 53 54 2E 20 C1 20 4C 4F 53 54 | BE LOST. . LOST|
000037B0: 20 4D 45 53 53 41 47 45 20 43 4F 55 4C 44 0D 52 | MESSAGE COULD.R|
000037C0: 45 53 55 4C 54 20 49 4E 20 41 20 50 52 4F 54 4F |ESULT IN A PROTO|
000037D0: 43 4F 4C 20 22 44 45 41 44 4C 4F 43 4B 22 20 49 |COL "DEADLOCK" I|
000037E0: 4E 20 57 48 49 43 48 20 4F 4E 45 20 53 59 53 54 |N WHICH ONE SYST|
000037F0: 45 4D 20 49 53 20 57 41 49 54 49 4E 47 20 46 4F |EM IS WAITING FO|
00003800: 52 45 56 45 52 20 46 4F 52 20 54 48 45 0D 4D 45 |REVER FOR THE.ME|
00003810: 53 53 41 47 45 20 57 48 49 4C 45 20 54 48 45 20 |SSAGE WHILE THE |
00003820: 4F 54 48 45 52 20 57 41 49 54 53 20 46 4F 52 20 |OTHER WAITS FOR |
00003830: 41 20 52 45 53 50 4F 4E 53 45 2E 20 20 D3 4F 4D |A RESPONSE. .OM|
00003840: 45 20 53 59 53 54 45 4D 53 20 43 41 4E 20 53 45 |E SYSTEMS CAN SE|
00003850: 54 20 54 49 4D 45 52 0D 49 4E 54 45 52 52 55 50 |T TIMER.INTERRUP|
00003860: 54 53 20 54 4F 20 41 4C 4C 4F 57 20 45 53 43 41 |TS TO ALLOW ESCA|
00003870: 50 45 20 46 52 4F 4D 20 50 4F 54 45 4E 54 49 41 |PE FROM POTENTIA|
00003880: 4C 4C 59 20 42 4C 4F 43 4B 49 4E 47 20 4F 50 45 |LLY BLOCKING OPE|
00003890: 52 41 54 49 4F 4E 53 3B 20 4F 54 48 45 52 53 2C |RATIONS; OTHERS,|
000038A0: 0D 49 4E 43 4C 55 44 49 4E 47 20 4D 41 4E 59 20 |.INCLUDING MANY |
000038B0: 4D 49 43 52 4F 43 4F 4D 50 55 54 45 52 53 2C 20 |MICROCOMPUTERS, |
000038C0: 43 41 4E 20 4E 4F 54 20 44 4F 20 53 4F 2E 20 20 |CAN NOT DO SO. |
000038D0: D7 48 45 4E 20 54 49 4D 45 4F 55 54 53 20 41 52 |.HEN TIMEOUTS AR|
000038E0: 45 20 4E 4F 54 20 50 4F 53 53 49 42 4C 45 2C 0D |E NOT POSSIBLE,.|
000038F0: 54 48 45 59 20 4D 41 59 20 42 45 20 53 49 4D 55 |THEY MAY BE SIMU|
00003900: 4C 41 54 45 44 20 42 59 20 53 4C 45 45 50 2D 41 |LATED BY SLEEP-A|
00003910: 4E 44 2D 54 45 53 54 20 4F 52 20 4C 4F 4F 50 2D |ND-TEST OR LOOP-|
00003920: 41 4E 44 2D 54 45 53 54 20 4F 50 45 52 41 54 49 |AND-TEST OPERATI|
00003930: 4F 4E 53 2C 20 4F 52 20 44 45 41 44 2D 0D 4C 4F |ONS, OR DEAD-.LO|
00003940: 43 4B 45 44 20 53 59 53 54 45 4D 53 20 4D 41 59 |CKED SYSTEMS MAY|
00003950: 20 42 45 20 41 57 41 4B 45 4E 45 44 20 42 59 20 | BE AWAKENED BY |
00003960: 4D 41 4E 55 41 4C 20 49 4E 54 45 52 56 45 4E 54 |MANUAL INTERVENT|
00003970: 49 4F 4E 2E 0D 0D C6 49 4C 45 20 CF 52 47 41 4E |ION....ILE .RGAN|
00003980: 49 5A 41 54 49 4F 4E 0D 0D D3 4F 4D 45 20 43 4F |IZATION...OME CO|
00003990: 4D 50 55 54 45 52 53 20 53 54 4F 52 45 20 41 4C |MPUTERS STORE AL|
000039A0: 4C 20 46 49 4C 45 53 20 49 4E 20 41 20 55 4E 49 |L FILES IN A UNI|
000039B0: 46 4F 52 4D 20 57 41 59 2C 20 53 55 43 48 20 41 |FORM WAY, SUCH A|
000039C0: 53 20 54 48 45 20 4C 49 4E 45 41 52 20 53 54 52 |S THE LINEAR STR|
000039D0: 45 41 4D 20 4F 46 0D 42 59 54 45 53 20 54 48 41 |EAM OF.BYTES THA|
000039E0: 54 20 49 53 20 41 20 D5 CE C9 D8 20 46 49 4C 45 |T IS A .... FILE|
000039F0: 2E 20 CF 54 48 45 52 20 43 4F 4D 50 55 54 45 52 |. .THER COMPUTER|
00003A00: 53 20 4D 41 59 20 48 41 56 45 20 4D 4F 52 45 20 |S MAY HAVE MORE |
00003A10: 43 4F 4D 50 4C 49 43 41 54 45 44 20 4F 52 0D 44 |COMPLICATED OR.D|
00003A20: 49 56 45 52 53 45 20 46 49 4C 45 20 4F 52 47 41 |IVERSE FILE ORGA|
00003A30: 4E 49 5A 41 54 49 4F 4E 53 20 41 4E 44 20 41 43 |NIZATIONS AND AC|
00003A40: 43 45 53 53 20 4D 45 54 48 4F 44 53 3A 20 52 45 |CESS METHODS: RE|
00003A50: 43 4F 52 44 2D 4F 52 49 45 4E 54 45 44 20 53 54 |CORD-ORIENTED ST|
00003A60: 4F 52 41 47 45 20 57 49 54 48 0D 49 54 53 20 4D |ORAGE WITH.ITS M|
00003A70: 41 4E 59 20 56 41 52 49 41 54 49 4F 4E 53 2C 20 |ANY VARIATIONS, |
00003A80: 45 58 45 4D 50 4C 49 46 49 45 44 20 49 4E 20 C9 |EXEMPLIFIED IN .|
00003A90: C2 CD 20 CF D3 2F 33 36 30 20 4F 52 20 C4 C5 C3 |.. ../360 OR ...|
00003AA0: 20 D2 CD D3 2E 20 C5 56 45 4E 20 53 49 4D 50 4C | .... .VEN SIMPL|
00003AB0: 45 0D 4D 49 43 52 4F 43 4F 4D 50 55 54 45 52 53 |E.MICROCOMPUTERS|
00003AC0: 20 43 41 4E 20 50 52 45 53 45 4E 54 20 43 4F 4D | CAN PRESENT COM|
00003AD0: 50 4C 49 43 41 54 49 4F 4E 53 20 57 48 45 4E 20 |PLICATIONS WHEN |
00003AE0: 46 49 4C 45 53 20 41 52 45 20 54 52 45 41 54 45 |FILES ARE TREATE|
00003AF0: 44 20 41 53 20 55 4E 49 46 4F 52 4D 0D 44 41 54 |D AS UNIFORM.DAT|
00003B00: 41 20 54 4F 20 42 45 20 54 52 41 4E 53 46 45 52 |A TO BE TRANSFER|
00003B10: 52 45 44 3B 20 46 4F 52 20 49 4E 53 54 41 4E 43 |RED; FOR INSTANC|
00003B20: 45 20 55 4E 44 45 52 20 C3 D0 2F CD 2C 20 54 48 |E UNDER ../., TH|
00003B30: 45 20 45 4E 44 53 20 4F 46 20 42 49 4E 41 52 59 |E ENDS OF BINARY|
00003B40: 20 41 4E 44 20 54 45 58 54 0D 46 49 4C 45 53 20 | AND TEXT.FILES |
00003B50: 41 52 45 20 44 45 54 45 52 4D 49 4E 45 44 20 44 |ARE DETERMINED D|
00003B60: 49 46 46 45 52 45 4E 54 4C 59 2E 20 20 C1 20 4D |IFFERENTLY. . M|
00003B70: 41 4A 4F 52 20 51 55 45 53 54 49 4F 4E 20 49 4E |AJOR QUESTION IN|
00003B80: 20 41 4E 59 20 4F 50 45 52 41 54 49 4E 47 20 53 | ANY OPERATING S|
00003B90: 59 53 54 45 4D 20 49 53 0D 57 48 45 54 48 45 52 |YSTEM IS.WHETHER|
00003BA0: 20 41 20 46 49 4C 45 20 49 53 20 53 50 45 43 49 | A FILE IS SPECI|
00003BB0: 46 49 45 44 20 53 55 46 46 49 43 49 45 4E 54 4C |FIED SUFFICIENTL|
00003BC0: 59 20 42 59 20 49 54 53 20 43 4F 4E 54 45 4E 54 |Y BY ITS CONTENT|
00003BD0: 53 20 41 4E 44 20 49 54 53 20 4E 41 4D 45 2C 20 |S AND ITS NAME, |
00003BE0: 4F 52 20 49 46 0D 41 44 44 49 54 49 4F 4E 41 4C |OR IF.ADDITIONAL|
00003BF0: 20 45 58 54 45 52 4E 41 4C 20 49 4E 46 4F 52 4D | EXTERNAL INFORM|
00003C00: 41 54 49 4F 4E 20 49 53 20 52 45 51 55 49 52 45 |ATION IS REQUIRE|
00003C10: 44 20 54 4F 20 4D 41 4B 45 20 54 48 45 20 46 49 |D TO MAKE THE FI|
00003C20: 4C 45 20 56 41 4C 49 44 2E 20 C1 20 53 49 4D 50 |LE VALID. . SIMP|
00003C30: 4C 45 0D 47 45 4E 45 52 41 4C 49 5A 45 44 20 46 |LE.GENERALIZED F|
00003C40: 49 4C 45 20 54 52 41 4E 53 46 45 52 20 46 41 43 |ILE TRANSFER FAC|
00003C50: 49 4C 49 54 59 20 43 41 4E 20 42 45 20 45 58 50 |ILITY CAN BE EXP|
00003C60: 45 43 54 45 44 20 54 4F 20 54 52 41 4E 53 4D 49 |ECTED TO TRANSMI|
00003C70: 54 20 41 20 46 49 4C 45 27 53 20 4E 41 4D 45 0D |T A FILE'S NAME.|
00003C80: 41 4E 44 20 43 4F 4E 54 45 4E 54 53 2C 20 42 55 |AND CONTENTS, BU|
00003C90: 54 20 4E 4F 54 20 45 56 45 52 59 20 43 4F 4E 43 |T NOT EVERY CONC|
00003CA0: 45 49 56 41 42 4C 45 20 41 54 54 52 49 42 55 54 |EIVABLE ATTRIBUT|
00003CB0: 45 20 41 20 46 49 4C 45 20 4D 49 47 48 54 20 50 |E A FILE MIGHT P|
00003CC0: 4F 53 53 45 53 53 2E 0D 0D C4 45 53 49 47 4E 45 |OSSESS....ESIGNE|
00003CD0: 52 53 20 4F 46 20 45 58 50 45 4E 53 49 56 45 20 |RS OF EXPENSIVE |
00003CE0: 4E 45 54 57 4F 52 4B 53 20 48 41 56 45 20 47 4F |NETWORKS HAVE GO|
00003CF0: 4E 45 20 54 4F 20 47 52 45 41 54 20 4C 45 4E 47 |NE TO GREAT LENG|
00003D00: 54 48 53 20 54 4F 20 50 41 53 53 20 46 49 4C 45 |THS TO PASS FILE|
00003D10: 0D 41 54 54 52 49 42 55 54 45 53 20 41 4C 4F 4E |.ATTRIBUTES ALON|
00003D20: 47 20 57 48 45 4E 20 54 52 41 4E 53 46 45 52 52 |G WHEN TRANSFERR|
00003D30: 49 4E 47 20 46 49 4C 45 53 20 42 45 54 57 45 45 |ING FILES BETWEE|
00003D40: 4E 20 55 4E 4C 49 4B 45 20 53 59 53 54 45 4D 53 |N UNLIKE SYSTEMS|
00003D50: 2E 20 20 C6 4F 52 20 49 4E 53 54 41 4E 43 45 2C |. .OR INSTANCE,|
00003D60: 0D 54 48 45 20 C4 C5 C3 4E 45 54 20 C4 41 54 41 |.THE ...NET .ATA|
00003D70: 20 C1 43 43 45 53 53 20 D0 52 4F 54 4F 43 4F 4C | .CCESS .ROTOCOL|
00003D80: 20 2D C4 C1 D0 20 53 55 50 50 4F 52 54 53 20 34 | -... SUPPORTS 4|
00003D90: 32 20 44 49 46 46 45 52 45 4E 54 20 22 47 45 4E |2 DIFFERENT "GEN|
00003DA0: 45 52 49 43 20 53 59 53 54 45 4D 0D 43 41 50 41 |ERIC SYSTEM.CAPA|
00003DB0: 42 49 4C 49 54 49 45 53 22 20 28 4C 49 4B 45 20 |BILITIES" (LIKE |
00003DC0: 57 48 45 54 48 45 52 20 46 49 4C 45 53 20 43 41 |WHETHER FILES CA|
00003DD0: 4E 20 42 45 20 50 52 45 41 4C 4C 4F 43 41 54 45 |N BE PREALLOCATE|
00003DE0: 44 2C 20 41 50 50 45 4E 44 45 44 20 54 4F 2C 20 |D, APPENDED TO, |
00003DF0: 41 43 43 45 53 53 45 44 0D 52 41 4E 44 4F 4D 4C |ACCESSED.RANDOML|
00003E00: 59 2C 20 45 54 43 29 2C 20 38 20 44 41 54 41 20 |Y, ETC), 8 DATA |
00003E10: 54 59 50 45 53 20 28 C1 D3 C3 C9 C9 2C 20 C5 C2 |TYPES (....., ..|
00003E20: C3 C4 C9 C3 2C 20 45 58 45 43 55 54 41 42 4C 45 |...., EXECUTABLE|
00003E30: 2C 20 45 54 43 29 2C 20 34 20 4F 52 47 41 4E 49 |, ETC), 4 ORGANI|
00003E40: 5A 41 54 49 4F 4E 53 0D 28 53 45 51 55 45 4E 54 |ZATIONS.(SEQUENT|
00003E50: 49 41 4C 2C 20 52 45 4C 41 54 49 56 45 2C 20 49 |IAL, RELATIVE, I|
00003E60: 4E 44 45 58 45 44 2C 20 48 41 53 48 45 44 29 2C |NDEXED, HASHED),|
00003E70: 20 35 20 52 45 43 4F 52 44 20 46 4F 52 4D 41 54 | 5 RECORD FORMAT|
00003E80: 53 20 28 46 49 58 45 44 2C 20 56 41 52 49 41 42 |S (FIXED, VARIAB|
00003E90: 4C 45 2C 0D 45 54 43 29 2C 20 38 20 52 45 43 4F |LE,.ETC), 8 RECO|
00003EA0: 52 44 20 41 54 54 52 49 42 55 54 45 53 20 28 46 |RD ATTRIBUTES (F|
00003EB0: 4F 52 20 46 4F 52 4D 41 54 20 43 4F 4E 54 52 4F |OR FORMAT CONTRO|
00003EC0: 4C 29 2C 20 31 34 20 46 49 4C 45 20 41 4C 4C 4F |L), 14 FILE ALLO|
00003ED0: 43 41 54 49 4F 4E 20 41 54 54 52 49 42 55 54 45 |CATION ATTRIBUTE|
00003EE0: 53 0D 28 42 59 54 45 20 53 49 5A 45 2C 20 52 45 |S.(BYTE SIZE, RE|
00003EF0: 43 4F 52 44 20 53 49 5A 45 2C 20 42 4C 4F 43 4B |CORD SIZE, BLOCK|
00003F00: 20 53 49 5A 45 2C 20 45 54 43 29 2C 20 32 38 20 | SIZE, ETC), 28 |
00003F10: 41 43 43 45 53 53 20 4F 50 54 49 4F 4E 53 20 28 |ACCESS OPTIONS (|
00003F20: 53 55 50 45 52 53 45 44 45 2C 0D 55 50 44 41 54 |SUPERSEDE,.UPDAT|
00003F30: 45 2C 20 41 50 50 45 4E 44 2C 20 52 45 57 49 4E |E, APPEND, REWIN|
00003F40: 44 2C 20 45 54 43 29 2C 20 32 36 20 44 45 56 49 |D, ETC), 26 DEVI|
00003F50: 43 45 20 43 48 41 52 41 43 54 45 52 49 53 54 49 |CE CHARACTERISTI|
00003F60: 43 53 20 28 54 45 52 4D 49 4E 41 4C 2C 20 44 49 |CS (TERMINAL, DI|
00003F70: 52 45 43 54 4F 52 59 0D 53 54 52 55 43 54 55 52 |RECTORY.STRUCTUR|
00003F80: 45 44 2C 20 53 48 41 52 45 44 2C 20 53 50 4F 4F |ED, SHARED, SPOO|
00003F90: 4C 45 44 2C 20 45 54 43 29 2C 20 56 41 52 49 4F |LED, ETC), VARIO|
00003FA0: 55 53 20 41 43 43 45 53 53 20 4F 50 54 49 4F 4E |US ACCESS OPTION|
00003FB0: 53 20 28 4E 45 57 2C 20 4F 4C 44 2C 20 52 45 4E |S (NEW, OLD, REN|
00003FC0: 41 4D 45 2C 0D 50 41 53 53 57 4F 52 44 2C 20 45 |AME,.PASSWORD, E|
00003FD0: 54 43 29 2C 20 49 4E 20 41 44 44 49 54 49 4F 4E |TC), IN ADDITION|
00003FE0: 20 54 4F 20 54 48 45 20 42 45 54 54 45 52 20 4B | TO THE BETTER K|
00003FF0: 4E 4F 57 4E 20 46 49 4C 45 20 41 54 54 52 49 42 |NOWN FILE ATTRIB|
00004000: 55 54 45 53 20 4C 49 4B 45 20 4E 41 4D 45 2C 0D |UTES LIKE NAME,.|
00004010: 43 52 45 41 54 49 4F 4E 20 44 41 54 45 2C 20 50 |CREATION DATE, P|
00004020: 52 4F 54 45 43 54 49 4F 4E 20 43 4F 44 45 2C 20 |ROTECTION CODE, |
00004030: 41 4E 44 20 53 4F 20 4F 4E 2E 20 20 C1 4C 4C 20 |AND SO ON. .LL |
00004040: 54 48 49 53 20 57 41 53 20 44 45 45 4D 45 44 20 |THIS WAS DEEMED |
00004050: 4E 45 43 45 53 53 41 52 59 20 45 56 45 4E 0D 57 |NECESSARY EVEN.W|
00004060: 48 45 4E 20 54 48 45 20 44 45 53 49 47 4E 45 52 |HEN THE DESIGNER|
00004070: 53 20 48 41 44 20 4F 4E 4C 59 20 41 20 53 4D 41 |S HAD ONLY A SMA|
00004080: 4C 4C 20 4E 55 4D 42 45 52 20 4F 46 20 4D 41 43 |LL NUMBER OF MAC|
00004090: 48 49 4E 45 53 20 54 4F 20 57 4F 52 52 59 20 41 |HINES TO WORRY A|
000040A0: 42 4F 55 54 2C 20 41 4C 4C 20 46 52 4F 4D 0D 41 |BOUT, ALL FROM.A|
000040B0: 20 53 49 4E 47 4C 45 20 56 45 4E 44 4F 52 2E 0D | SINGLE VENDOR..|
000040C0: D4 48 45 20 C1 D2 D0 C1 20 4E 45 54 57 4F 52 4B |.HE .... NETWORK|
000040D0: 2C 20 57 48 49 43 48 20 41 54 54 45 4D 50 54 53 |, WHICH ATTEMPTS|
000040E0: 20 54 4F 20 50 52 4F 56 49 44 45 20 53 45 52 56 | TO PROVIDE SERV|
000040F0: 49 43 45 53 20 46 4F 52 20 4D 41 4E 59 20 4D 4F |ICES FOR MANY MO|
00004100: 52 45 20 4D 41 43 48 49 4E 45 53 0D 46 52 4F 4D |RE MACHINES.FROM|
00004110: 20 4D 41 4E 59 20 56 45 4E 44 4F 52 53 2C 20 4D | MANY VENDORS, M|
00004120: 41 4B 45 53 20 53 4F 4D 45 20 53 49 4D 50 4C 49 |AKES SOME SIMPLI|
00004130: 46 59 49 4E 47 20 41 53 53 55 4D 50 54 49 4F 4E |FYING ASSUMPTION|
00004140: 53 20 41 4E 44 20 53 45 54 53 20 53 4F 4D 45 20 |S AND SETS SOME |
00004150: 52 45 53 54 52 49 43 2D 0D 54 49 4F 4E 53 20 49 |RESTRIC-.TIONS I|
00004160: 4E 20 49 54 53 20 C6 49 4C 45 20 D4 52 41 4E 53 |N ITS .ILE .RANS|
00004170: 46 45 52 20 D0 52 4F 54 4F 43 4F 4C 20 28 C6 D4 |FER .ROTOCOL (..|
00004180: D0 29 2E 20 C1 4C 4C 20 46 49 4C 45 53 20 41 52 |.). .LL FILES AR|
00004190: 45 20 46 4F 52 43 45 44 20 49 4E 54 4F 20 43 45 |E FORCED INTO CE|
000041A0: 52 54 41 49 4E 0D 43 41 54 45 47 4F 52 49 45 53 |RTAIN.CATEGORIES|
000041B0: 20 57 49 54 48 20 52 45 53 50 45 43 54 20 54 4F | WITH RESPECT TO|
000041C0: 20 45 4E 43 4F 44 49 4E 47 20 28 C1 D3 C3 C9 C9 | ENCODING (.....|
000041D0: 2C 20 C5 C2 C3 C4 C9 C3 2C 20 49 4D 41 47 45 29 |, ......, IMAGE)|
000041E0: 2C 20 52 45 43 4F 52 44 20 46 4F 52 4D 41 54 0D |, RECORD FORMAT.|
000041F0: 43 4F 4E 54 52 4F 4C 2C 20 42 59 54 45 20 53 49 |CONTROL, BYTE SI|
00004200: 5A 45 2C 20 46 49 4C 45 20 53 54 52 55 43 54 55 |ZE, FILE STRUCTU|
00004210: 52 45 20 28 52 45 43 4F 52 44 20 4F 52 20 53 54 |RE (RECORD OR ST|
00004220: 52 45 41 4D 29 2C 20 41 4E 44 20 49 54 20 49 53 |REAM), AND IT IS|
00004230: 20 47 45 4E 45 52 41 4C 4C 59 0D 4C 45 46 54 20 | GENERALLY.LEFT |
00004240: 54 4F 20 54 48 45 20 48 4F 53 54 20 C6 D4 D0 20 |TO THE HOST ... |
00004250: 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E 20 54 |IMPLEMENTATION T|
00004260: 4F 20 44 4F 20 54 48 45 20 4E 45 43 45 53 53 41 |O DO THE NECESSA|
00004270: 52 59 20 54 52 41 4E 53 46 4F 52 4D 41 54 49 4F |RY TRANSFORMATIO|
00004280: 4E 53 2E 0D CE 4F 20 50 41 52 54 49 43 55 4C 41 |NS...O PARTICULA|
00004290: 52 20 50 52 4F 56 49 53 49 4F 4E 20 49 53 20 4D |R PROVISION IS M|
000042A0: 41 44 45 2C 20 4F 52 20 43 41 4E 20 42 45 20 4D |ADE, OR CAN BE M|
000042B0: 41 44 45 2C 20 54 4F 20 45 4E 53 55 52 45 20 54 |ADE, TO ENSURE T|
000042C0: 48 41 54 20 53 55 43 48 20 54 52 41 4E 53 2D 0D |HAT SUCH TRANS-.|
000042D0: 46 4F 52 4D 41 54 49 4F 4E 53 20 41 52 45 20 49 |FORMATIONS ARE I|
000042E0: 4E 56 45 52 54 49 42 4C 45 2E 0D C4 C5 C3 4E 45 |NVERTIBLE.....NE|
000042F0: 54 20 49 53 20 41 42 4C 45 20 54 4F 20 50 52 4F |T IS ABLE TO PRO|
00004300: 56 49 44 45 20 49 4E 56 45 52 54 49 42 49 4C 49 |VIDE INVERTIBILI|
00004310: 54 59 20 46 4F 52 20 4F 50 45 52 41 54 49 4E 47 |TY FOR OPERATING|
00004320: 20 53 59 53 54 45 4D 53 20 4C 49 4B 45 20 D6 CD | SYSTEMS LIKE ..|
00004330: D3 20 4F 52 20 D2 D3 D8 2C 0D 57 48 49 43 48 20 |. OR ...,.WHICH |
00004340: 43 41 4E 20 53 54 4F 52 45 20 54 48 45 20 4E 45 |CAN STORE THE NE|
00004350: 43 45 53 53 41 52 59 20 46 49 4C 45 20 41 54 54 |CESSARY FILE ATT|
00004360: 52 49 42 55 54 45 53 20 41 4C 4F 4E 47 20 57 49 |RIBUTES ALONG WI|
00004370: 54 48 20 54 48 45 20 46 49 4C 45 2E 20 20 C2 55 |TH THE FILE. .U|
00004380: 54 20 53 49 4D 50 4C 45 52 0D 46 49 4C 45 20 53 |T SIMPLER.FILE S|
00004390: 59 53 54 45 4D 53 2C 20 4C 49 4B 45 20 54 48 4F |YSTEMS, LIKE THO|
000043A0: 53 45 20 4F 46 20 D4 CF D0 D3 2D 31 30 20 4F 52 |SE OF ....-10 OR|
000043B0: 20 D4 CF D0 D3 2D 32 30 2C 20 43 41 4E 20 4C 4F | ....-20, CAN LO|
000043C0: 53 45 20 56 49 54 41 4C 20 49 4E 46 4F 52 4D 41 |SE VITAL INFORMA|
000043D0: 54 49 4F 4E 0D 41 42 4F 55 54 20 49 4E 43 4F 4D |TION.ABOUT INCOM|
000043E0: 49 4E 47 20 46 49 4C 45 53 2E 20 C6 4F 52 20 49 |ING FILES. .OR I|
000043F0: 4E 53 54 41 4E 43 45 2C 20 49 46 20 D6 CD D3 20 |NSTANCE, IF ... |
00004400: 52 45 51 55 49 52 45 53 20 53 4F 4D 45 20 54 59 |REQUIRES SOME TY|
00004410: 50 45 20 4F 46 20 46 49 4C 45 20 54 4F 20 48 41 |PE OF FILE TO HA|
00004420: 56 45 20 41 0D 53 50 45 43 49 46 49 43 20 42 4C |VE A.SPECIFIC BL|
00004430: 4F 43 4B 53 49 5A 45 2C 20 57 48 49 4C 45 20 D4 |OCKSIZE, WHILE .|
00004440: CF D0 D3 2D 32 30 20 48 41 53 20 4E 4F 20 43 4F |...-20 HAS NO CO|
00004450: 4E 43 45 50 54 20 4F 46 20 42 4C 4F 43 4B 20 53 |NCEPT OF BLOCK S|
00004460: 49 5A 45 2C 20 54 48 45 4E 20 54 48 45 20 42 4C |IZE, THEN THE BL|
00004470: 4F 43 4B 2D 0D 53 49 5A 45 20 57 49 4C 4C 20 42 |OCK-.SIZE WILL B|
00004480: 45 20 4C 4F 53 54 20 55 50 4F 4E 20 54 52 41 4E |E LOST UPON TRAN|
00004490: 53 46 45 52 20 46 52 4F 4D 20 D6 CD D3 20 54 4F |SFER FROM ... TO|
000044A0: 20 D4 CF D0 D3 2D 32 30 20 41 4E 44 20 43 41 4E | ....-20 AND CAN|
000044B0: 4E 4F 54 20 42 45 20 52 45 53 54 4F 52 45 44 0D |NOT BE RESTORED.|
000044C0: 41 55 54 4F 4D 41 54 49 43 41 4C 4C 59 20 57 48 |AUTOMATICALLY WH|
000044D0: 45 4E 20 54 48 45 20 46 49 4C 45 20 49 53 20 53 |EN THE FILE IS S|
000044E0: 45 4E 54 20 42 41 43 4B 2C 20 4C 45 41 56 49 4E |ENT BACK, LEAVIN|
000044F0: 47 20 54 48 45 20 52 45 53 55 4C 54 20 50 4F 54 |G THE RESULT POT|
00004500: 45 4E 54 49 41 4C 4C 59 0D 55 4E 55 53 41 42 4C |ENTIALLY.UNUSABL|
00004510: 45 2E 0D 0D C9 4E 56 45 52 54 49 42 49 4C 49 54 |E....NVERTIBILIT|
00004520: 59 20 49 53 20 41 20 4D 41 4A 4F 52 20 50 52 4F |Y IS A MAJOR PRO|
00004530: 42 4C 45 4D 2C 20 57 49 54 48 20 4E 4F 20 53 49 |BLEM, WITH NO SI|
00004540: 4D 50 4C 45 20 53 4F 4C 55 54 49 4F 4E 2E 20 C6 |MPLE SOLUTION. .|
00004550: 4F 52 54 55 4E 41 54 45 4C 59 2C 20 4D 4F 53 54 |ORTUNATELY, MOST|
00004560: 0D 46 49 4C 45 20 54 52 41 4E 53 46 45 52 20 42 |.FILE TRANSFER B|
00004570: 45 54 57 45 45 4E 20 55 4E 4C 49 4B 45 20 53 59 |ETWEEN UNLIKE SY|
00004580: 53 54 45 4D 53 20 49 4E 56 4F 4C 56 45 53 20 4F |STEMS INVOLVES O|
00004590: 4E 4C 59 20 54 45 58 54 55 41 4C 20 49 4E 46 4F |NLY TEXTUAL INFO|
000045A0: 52 4D 41 54 49 4F 4E 20 2D 20 44 41 54 41 2C 0D |RMATION - DATA,.|
000045B0: 44 4F 43 55 4D 45 4E 54 53 2C 20 50 52 4F 47 52 |DOCUMENTS, PROGR|
000045C0: 41 4D 20 53 4F 55 52 43 45 20 2D 20 57 48 49 43 |AM SOURCE - WHIC|
000045D0: 48 20 49 53 20 53 45 51 55 45 4E 54 49 41 4C 20 |H IS SEQUENTIAL |
000045E0: 49 4E 20 4F 52 47 41 4E 49 5A 41 54 49 4F 4E 2C |IN ORGANIZATION,|
000045F0: 20 41 4E 44 20 46 4F 52 20 57 48 49 43 48 0D 41 | AND FOR WHICH.A|
00004600: 4E 59 20 52 45 51 55 49 52 45 44 20 54 52 41 4E |NY REQUIRED TRAN|
00004610: 53 46 4F 52 4D 41 54 49 4F 4E 53 20 28 45 2E 47 |SFORMATIONS (E.G|
00004620: 2E 20 42 4C 4F 43 4B 45 44 20 54 4F 20 53 54 52 |. BLOCKED TO STR|
00004630: 45 41 4D 2C 20 C5 C2 C3 C4 C9 C3 20 54 4F 20 C1 |EAM, ...... TO .|
00004640: D3 C3 C9 C9 29 20 41 52 45 0D 53 49 4D 50 4C 45 |....) ARE.SIMPLE|
00004650: 20 41 4E 44 20 4E 4F 54 20 44 45 50 45 4E 44 45 | AND NOT DEPENDE|
00004660: 4E 54 20 4F 4E 20 41 4E 59 20 53 50 45 43 49 41 |NT ON ANY SPECIA|
00004670: 4C 20 46 49 4C 45 20 41 54 54 52 49 42 55 54 45 |L FILE ATTRIBUTE|
00004680: 53 2E 0D 0D C9 4E 20 46 41 43 54 2C 20 49 4E 56 |S....N FACT, INV|
00004690: 45 52 54 41 42 49 4C 49 54 59 20 43 41 4E 20 42 |ERTABILITY CAN B|
000046A0: 45 20 41 43 48 49 45 56 45 44 20 49 46 20 54 48 |E ACHIEVED IF TH|
000046B0: 41 54 20 49 53 20 54 48 45 20 50 52 49 4D 41 52 |AT IS THE PRIMAR|
000046C0: 59 20 47 4F 41 4C 20 4F 46 20 41 20 46 49 4C 45 |Y GOAL OF A FILE|
000046D0: 0D 54 52 41 4E 53 46 45 52 20 50 52 4F 54 4F 43 |.TRANSFER PROTOC|
000046E0: 4F 4C 2E 20 C1 4C 4C 20 54 48 45 20 45 58 54 45 |OL. .LL THE EXTE|
000046F0: 52 4E 41 4C 20 41 54 54 52 49 42 55 54 45 53 20 |RNAL ATTRIBUTES |
00004700: 4F 46 20 41 20 46 49 4C 45 20 43 41 4E 20 42 45 |OF A FILE CAN BE|
00004710: 20 45 4E 43 4F 44 45 44 20 41 4E 44 0D 49 4E 43 | ENCODED AND.INC|
00004720: 4C 55 44 45 44 20 57 49 54 48 20 54 48 45 20 43 |LUDED WITH THE C|
00004730: 4F 4E 54 45 4E 54 53 20 4F 46 20 54 48 45 20 46 |ONTENTS OF THE F|
00004740: 49 4C 45 20 54 4F 20 42 45 20 53 54 4F 52 45 44 |ILE TO BE STORED|
00004750: 20 4F 4E 20 54 48 45 20 52 45 4D 4F 54 45 20 53 | ON THE REMOTE S|
00004760: 59 53 54 45 4D 2E 0D C6 4F 52 20 55 4E 4C 49 4B |YSTEM...OR UNLIK|
00004770: 45 20 53 59 53 54 45 4D 53 2C 20 54 48 49 53 20 |E SYSTEMS, THIS |
00004780: 43 41 4E 20 52 45 4E 44 45 52 20 54 48 45 20 46 |CAN RENDER THE F|
00004790: 49 4C 45 20 4C 45 53 53 20 54 48 41 4E 20 55 53 |ILE LESS THAN US|
000047A0: 45 46 55 4C 20 4F 4E 20 54 48 45 20 54 41 52 47 |EFUL ON THE TARG|
000047B0: 45 54 0D 53 59 53 54 45 4D 2C 20 42 55 54 20 41 |ET.SYSTEM, BUT A|
000047C0: 4C 4C 4F 57 53 20 49 54 20 54 4F 20 42 45 20 52 |LLOWS IT TO BE R|
000047D0: 45 53 54 4F 52 45 44 20 43 4F 52 52 45 43 54 4C |ESTORED CORRECTL|
000047E0: 59 20 55 50 4F 4E 20 52 45 54 55 52 4E 2E 20 20 |Y UPON RETURN. |
000047F0: C8 4F 57 45 56 45 52 2C 20 49 54 20 49 53 0D 4D |.OWEVER, IT IS.M|
00004800: 4F 52 45 20 43 4F 4D 4D 4F 4E 4C 59 20 44 45 53 |ORE COMMONLY DES|
00004810: 49 52 45 44 20 54 48 41 54 20 54 45 58 54 55 41 |IRED THAT TEXTUA|
00004820: 4C 20 46 49 4C 45 53 20 52 45 4D 41 49 4E 20 49 |L FILES REMAIN I|
00004830: 4E 54 45 4C 4C 49 47 49 42 4C 45 20 57 48 45 4E |NTELLIGIBLE WHEN|
00004840: 20 54 52 41 4E 53 46 45 52 52 45 44 0D 54 4F 20 | TRANSFERRED.TO |
00004850: 41 20 46 4F 52 45 49 47 4E 20 53 59 53 54 45 4D |A FOREIGN SYSTEM|
00004860: 2C 20 45 56 45 4E 20 49 46 20 54 52 41 4E 53 46 |, EVEN IF TRANSF|
00004870: 4F 52 4D 41 54 49 4F 4E 53 20 4D 55 53 54 20 42 |ORMATIONS MUST B|
00004880: 45 20 4D 41 44 45 2E 20 D4 4F 20 41 4C 4C 4F 57 |E MADE. .O ALLOW|
00004890: 20 54 48 45 0D 4E 45 43 45 53 53 41 52 59 20 54 | THE.NECESSARY T|
000048A0: 52 41 4E 53 46 4F 52 4D 41 54 49 4F 4E 53 20 54 |RANSFORMATIONS T|
000048B0: 4F 20 54 41 4B 45 20 50 4C 41 43 45 20 4F 4E 20 |O TAKE PLACE ON |
000048C0: 54 45 58 54 55 41 4C 20 46 49 4C 45 53 20 42 45 |TEXTUAL FILES BE|
000048D0: 54 57 45 45 4E 20 55 4E 4C 49 4B 45 0D 53 59 53 |TWEEN UNLIKE.SYS|
000048E0: 54 45 4D 53 2C 20 54 48 45 52 45 20 4D 55 53 54 |TEMS, THERE MUST|
000048F0: 20 42 45 20 41 20 53 54 41 4E 44 41 52 44 20 57 | BE A STANDARD W|
00004900: 41 59 20 4F 46 20 52 45 50 52 45 53 45 4E 54 49 |AY OF REPRESENTI|
00004910: 4E 47 20 54 48 45 53 45 20 46 49 4C 45 53 20 44 |NG THESE FILES D|
00004920: 55 52 49 4E 47 0D 54 52 41 4E 53 4D 49 53 53 49 |URING.TRANSMISSI|
00004930: 4F 4E 2E 0D 0D C2 49 4E 41 52 59 20 C6 49 4C 45 |ON....INARY .ILE|
00004940: 53 20 56 45 52 53 55 53 20 D0 41 52 49 54 59 0D |S VERSUS .ARITY.|
00004950: 0D C5 41 43 48 20 C1 D3 C3 C9 C9 20 43 48 41 52 |..ACH ..... CHAR|
00004960: 41 43 54 45 52 20 49 53 20 52 45 50 52 45 53 45 |ACTER IS REPRESE|
00004970: 4E 54 45 44 20 42 59 20 41 20 53 54 52 49 4E 47 |NTED BY A STRING|
00004980: 20 4F 46 20 37 20 42 49 54 53 2E 20 D0 52 49 4E | OF 7 BITS. .RIN|
00004990: 54 41 42 4C 45 20 C1 D3 C3 C9 C9 0D 46 49 4C 45 |TABLE ......FILE|
000049A0: 53 20 43 41 4E 20 42 45 20 54 52 41 4E 53 4D 49 |S CAN BE TRANSMI|
000049B0: 54 54 45 44 20 49 4E 20 41 20 53 54 52 41 49 47 |TTED IN A STRAIG|
000049C0: 48 54 46 4F 52 57 41 52 44 20 46 41 53 48 49 4F |HTFORWARD FASHIO|
000049D0: 4E 2C 20 42 45 43 41 55 53 45 20 C1 D3 C3 C9 C9 |N, BECAUSE .....|
000049E0: 0D 54 52 41 4E 53 4D 49 53 53 49 4F 4E 20 49 53 |.TRANSMISSION IS|
000049F0: 20 44 45 53 49 47 4E 45 44 20 46 4F 52 20 54 48 | DESIGNED FOR TH|
00004A00: 45 4D 3A 20 41 20 53 45 52 49 41 4C 20 53 54 52 |EM: A SERIAL STR|
00004A10: 45 41 4D 20 4F 46 20 38 2D 42 49 54 20 43 48 41 |EAM OF 8-BIT CHA|
00004A20: 52 41 43 54 45 52 53 2C 20 37 20 42 49 54 53 0D |RACTERS, 7 BITS.|
00004A30: 46 4F 52 20 44 41 54 41 20 41 4E 44 20 31 20 46 |FOR DATA AND 1 F|
00004A40: 4F 52 20 50 41 52 49 54 59 2C 20 46 52 41 4D 45 |OR PARITY, FRAME|
00004A50: 44 20 42 59 20 53 54 41 52 54 20 41 4E 44 20 53 |D BY START AND S|
00004A60: 54 4F 50 20 42 49 54 53 20 46 4F 52 20 54 48 45 |TOP BITS FOR THE|
00004A70: 20 42 45 4E 45 46 49 54 20 4F 46 0D 54 48 45 20 | BENEFIT OF.THE |
00004A80: 48 41 52 44 57 41 52 45 2E 20 D4 48 45 20 50 41 |HARDWARE. .HE PA|
00004A90: 52 49 54 59 20 42 49 54 20 49 53 20 41 44 44 45 |RITY BIT IS ADDE|
00004AA0: 44 20 41 53 20 41 20 43 48 45 43 4B 20 4F 4E 20 |D AS A CHECK ON |
00004AB0: 54 48 45 20 49 4E 54 45 47 52 49 54 59 20 4F 46 |THE INTEGRITY OF|
00004AC0: 20 41 0D 43 48 41 52 41 43 54 45 52 3B 20 53 4F | A.CHARACTER; SO|
00004AD0: 4D 45 20 53 59 53 54 45 4D 53 20 41 4C 57 41 59 |ME SYSTEMS ALWAY|
00004AE0: 53 20 54 52 41 4E 53 4D 49 54 20 50 41 52 49 54 |S TRANSMIT PARIT|
00004AF0: 59 2C 20 4F 54 48 45 52 53 20 49 4E 53 49 53 54 |Y, OTHERS INSIST|
00004B00: 20 4F 4E 20 50 41 52 49 54 59 20 46 4F 52 0D 49 | ON PARITY FOR.I|
00004B10: 4E 43 4F 4D 49 4E 47 20 43 48 41 52 41 43 54 45 |NCOMING CHARACTE|
00004B20: 52 53 2C 20 53 54 49 4C 4C 20 4F 54 48 45 52 53 |RS, STILL OTHERS|
00004B30: 20 49 47 4E 4F 52 45 20 54 48 45 20 50 41 52 49 | IGNORE THE PARI|
00004B40: 54 59 20 42 49 54 20 46 4F 52 20 43 4F 4D 4D 55 |TY BIT FOR COMMU|
00004B50: 4E 49 43 41 54 49 4F 4E 0D 50 55 52 50 4F 53 45 |NICATION.PURPOSE|
00004B60: 53 20 41 4E 44 20 50 41 53 53 20 49 54 20 41 4C |S AND PASS IT AL|
00004B70: 4F 4E 47 20 54 4F 20 54 48 45 20 53 4F 46 54 57 |ONG TO THE SOFTW|
00004B80: 41 52 45 2C 20 57 48 49 4C 45 20 53 54 49 4C 4C |ARE, WHILE STILL|
00004B90: 20 4F 54 48 45 52 53 20 44 49 53 43 41 52 44 20 | OTHERS DISCARD |
00004BA0: 49 54 0D 41 4C 54 4F 47 45 54 48 45 52 2E 20 20 |IT.ALTOGETHER. |
00004BB0: C9 4E 20 41 44 44 49 54 49 4F 4E 2C 20 43 4F 4D |.N ADDITION, COM|
00004BC0: 4D 55 4E 49 43 41 54 49 4F 4E 20 46 52 4F 4E 54 |MUNICATION FRONT|
00004BD0: 20 45 4E 44 53 20 4F 52 20 43 4F 4D 4D 4F 4E 20 | ENDS OR COMMON |
00004BE0: 43 41 52 52 49 45 52 53 20 4D 49 47 48 54 0D 55 |CARRIERS MIGHT.U|
00004BF0: 53 55 52 50 20 54 48 45 20 50 41 52 49 54 59 20 |SURP THE PARITY |
00004C00: 42 49 54 2C 20 52 45 47 41 52 44 4C 45 53 53 20 |BIT, REGARDLESS |
00004C10: 4F 46 20 57 48 41 54 20 54 48 45 20 53 59 53 54 |OF WHAT THE SYST|
00004C20: 45 4D 20 49 54 53 45 4C 46 20 4D 41 59 20 44 4F |EM ITSELF MAY DO|
00004C30: 2E 0D 0D C3 4F 4D 50 55 54 45 52 20 46 49 4C 45 |....OMPUTER FILE|
00004C40: 20 53 59 53 54 45 4D 53 20 47 45 4E 45 52 41 4C | SYSTEMS GENERAL|
00004C50: 4C 59 20 53 54 4F 52 45 20 41 4E 20 C1 D3 C3 C9 |LY STORE AN ....|
00004C60: C9 20 46 49 4C 45 20 41 53 20 41 20 53 45 51 55 |. FILE AS A SEQU|
00004C70: 45 4E 43 45 20 4F 46 20 45 49 54 48 45 52 0D 37 |ENCE OF EITHER.7|
00004C80: 2D 42 49 54 20 4F 52 20 38 2D 42 49 54 20 42 59 |-BIT OR 8-BIT BY|
00004C90: 54 45 53 2E 20 20 38 2D 42 49 54 20 42 59 54 45 |TES. 8-BIT BYTE|
00004CA0: 53 20 41 52 45 20 4D 4F 52 45 20 43 4F 4D 4D 4F |S ARE MORE COMMO|
00004CB0: 4E 2C 20 49 4E 20 57 48 49 43 48 20 54 48 45 20 |N, IN WHICH THE |
00004CC0: 38 54 48 20 42 49 54 20 4F 46 0D 45 41 43 48 20 |8TH BIT OF.EACH |
00004CD0: 42 59 54 45 20 49 53 20 53 55 50 45 52 46 4C 55 |BYTE IS SUPERFLU|
00004CE0: 4F 55 53 2E 20 20 C2 45 53 49 44 45 53 20 46 49 |OUS. .ESIDES FI|
00004CF0: 4C 45 53 20 43 4F 4D 50 4F 53 45 44 20 4F 46 20 |LES COMPOSED OF |
00004D00: C1 D3 C3 C9 C9 20 43 48 41 52 41 43 54 45 52 53 |..... CHARACTERS|
00004D10: 2C 0D 48 4F 57 45 56 45 52 2C 20 43 4F 4D 50 55 |,.HOWEVER, COMPU|
00004D20: 54 45 52 53 20 41 4C 53 4F 20 48 41 56 45 20 22 |TERS ALSO HAVE "|
00004D30: 42 49 4E 41 52 59 22 20 46 49 4C 45 53 2C 20 49 |BINARY" FILES, I|
00004D40: 4E 20 57 48 49 43 48 20 45 56 45 52 59 20 42 49 |N WHICH EVERY BI|
00004D50: 54 20 49 53 20 4D 45 41 4E 49 4E 47 46 55 4C 3B |T IS MEANINGFUL;|
00004D60: 0D 45 58 41 4D 50 4C 45 53 20 49 4E 43 4C 55 44 |.EXAMPLES INCLUD|
00004D70: 45 20 45 58 45 43 55 54 41 42 4C 45 20 22 43 4F |E EXECUTABLE "CO|
00004D80: 52 45 20 49 4D 41 47 45 53 22 20 4F 46 20 50 52 |RE IMAGES" OF PR|
00004D90: 4F 47 52 41 4D 53 2C 20 4E 55 4D 42 45 52 53 20 |OGRAMS, NUMBERS |
00004DA0: 53 54 4F 52 45 44 20 49 4E 0D 22 49 4E 54 45 52 |STORED IN."INTER|
00004DB0: 4E 41 4C 20 46 4F 52 4D 41 54 22 2C 20 44 41 54 |NAL FORMAT", DAT|
00004DC0: 41 42 41 53 45 53 20 57 49 54 48 20 49 4D 42 45 |ABASES WITH IMBE|
00004DD0: 44 44 45 44 20 50 4F 49 4E 54 45 52 53 2E 20 20 |DDED POINTERS. |
00004DE0: D3 55 43 48 20 42 49 4E 41 52 59 20 44 41 54 41 |.UCH BINARY DATA|
00004DF0: 20 4D 55 53 54 20 42 45 0D 4D 41 50 50 45 44 20 | MUST BE.MAPPED |
00004E00: 54 4F 20 C1 D3 C3 C9 C9 20 43 48 41 52 41 43 54 |TO ..... CHARACT|
00004E10: 45 52 53 20 46 4F 52 20 54 52 41 4E 53 4D 49 53 |ERS FOR TRANSMIS|
00004E20: 53 49 4F 4E 20 4F 56 45 52 20 53 45 52 49 41 4C |SION OVER SERIAL|
00004E30: 20 4C 49 4E 45 53 2E 20 20 D7 48 45 4E 20 54 57 | LINES. .HEN TW|
00004E40: 4F 0D 53 59 53 54 45 4D 53 20 41 4C 4C 4F 57 20 |O.SYSTEMS ALLOW |
00004E50: 54 48 45 20 55 53 45 52 2D 4C 45 56 45 4C 20 53 |THE USER-LEVEL S|
00004E60: 4F 46 54 57 41 52 45 20 54 4F 20 43 4F 4E 54 52 |OFTWARE TO CONTR|
00004E70: 4F 4C 20 54 48 45 20 50 41 52 49 54 59 20 42 49 |OL THE PARITY BI|
00004E80: 54 2C 20 54 48 45 20 C1 CE D3 C9 0D 53 54 41 4E |T, THE .....STAN|
00004E90: 44 41 52 44 53 20 4D 41 59 20 42 45 20 53 54 52 |DARDS MAY BE STR|
00004EA0: 45 54 43 48 45 44 20 54 4F 20 50 45 52 4D 49 54 |ETCHED TO PERMIT|
00004EB0: 20 54 48 45 20 54 52 41 4E 53 4D 49 53 53 49 4F | THE TRANSMISSIO|
00004EC0: 4E 20 4F 46 20 38 20 44 41 54 41 20 42 49 54 53 |N OF 8 DATA BITS|
00004ED0: 20 50 45 52 0D 43 48 41 52 41 43 54 45 52 2C 20 | PER.CHARACTER, |
00004EE0: 57 48 49 43 48 20 43 4F 52 52 45 53 50 4F 4E 44 |WHICH CORRESPOND|
00004EF0: 53 20 54 4F 20 54 48 45 20 42 59 54 45 20 53 49 |S TO THE BYTE SI|
00004F00: 5A 45 20 4F 46 20 4D 4F 53 54 20 4D 41 43 48 49 |ZE OF MOST MACHI|
00004F10: 4E 45 53 2E 20 C2 55 54 20 53 49 4E 43 45 20 4E |NES. .UT SINCE N|
00004F20: 4F 54 0D 41 4C 4C 20 43 4F 4D 50 55 54 45 52 53 |OT.ALL COMPUTERS|
00004F30: 20 41 4C 4C 4F 57 20 54 48 49 53 20 46 4C 45 58 | ALLOW THIS FLEX|
00004F40: 49 42 49 4C 49 54 59 2C 20 54 48 45 20 41 42 49 |IBILITY, THE ABI|
00004F50: 4C 49 54 59 20 54 4F 20 54 52 41 4E 53 46 45 52 |LITY TO TRANSFER|
00004F60: 20 42 49 4E 41 52 59 20 44 41 54 41 20 49 4E 0D | BINARY DATA IN.|
00004F70: 54 48 49 53 20 46 41 53 48 49 4F 4E 20 43 41 4E |THIS FASHION CAN|
00004F80: 4E 4F 54 20 42 45 20 41 53 53 55 4D 45 44 2E 0D |NOT BE ASSUMED..|
00004F90: 0D D3 4F 46 54 57 41 52 45 0D 0D C6 49 4E 41 4C |..OFTWARE...INAL|
00004FA0: 4C 59 2C 20 53 59 53 54 45 4D 53 20 44 49 46 46 |LY, SYSTEMS DIFF|
00004FB0: 45 52 20 49 4E 20 54 48 45 20 41 50 50 4C 49 43 |ER IN THE APPLIC|
00004FC0: 41 54 49 4F 4E 20 53 4F 46 54 57 41 52 45 20 54 |ATION SOFTWARE T|
00004FD0: 48 45 59 20 48 41 56 45 2E 20 C9 4E 20 50 41 52 |HEY HAVE. .N PAR|
00004FE0: 54 49 43 55 4C 41 52 2C 0D 4E 4F 20 53 59 53 54 |TICULAR,.NO SYST|
00004FF0: 45 4D 20 43 41 4E 20 42 45 20 41 53 53 55 4D 45 |EM CAN BE ASSUME|
00005000: 44 20 54 4F 20 48 41 56 45 20 41 20 50 41 52 54 |D TO HAVE A PART|
00005010: 49 43 55 4C 41 52 20 50 52 4F 47 52 41 4D 4D 49 |ICULAR PROGRAMMI|
00005020: 4E 47 20 4C 41 4E 47 55 41 47 45 2E 20 C5 56 45 |NG LANGUAGE. .VE|
00005030: 4E 0D 57 49 44 45 53 50 52 45 41 44 20 4C 41 4E |N.WIDESPREAD LAN|
00005040: 47 55 41 47 45 53 20 4C 49 4B 45 20 C6 CF D2 D4 |GUAGES LIKE ....|
00005050: D2 C1 CE 20 41 4E 44 20 C2 C1 D3 C9 C3 20 4D 41 |... AND ..... MA|
00005060: 59 20 42 45 20 4C 41 43 4B 49 4E 47 20 46 52 4F |Y BE LACKING FRO|
00005070: 4D 20 53 4F 4D 45 20 43 4F 4D 50 55 54 45 52 53 |M SOME COMPUTERS|
00005080: 2C 0D 45 49 54 48 45 52 20 42 45 43 41 55 53 45 |,.EITHER BECAUSE|
00005090: 20 54 48 45 59 20 48 41 56 45 20 4E 4F 54 20 42 | THEY HAVE NOT B|
000050A0: 45 45 4E 20 49 4D 50 4C 45 4D 45 4E 54 45 44 2C |EEN IMPLEMENTED,|
000050B0: 20 4F 52 20 42 45 43 41 55 53 45 20 54 48 45 59 | OR BECAUSE THEY|
000050C0: 20 41 52 45 20 50 52 4F 50 52 49 45 54 41 52 59 | ARE PROPRIETARY|
000050D0: 0D 41 4E 44 20 48 41 56 45 20 4E 4F 54 20 42 45 |.AND HAVE NOT BE|
000050E0: 45 4E 20 50 55 52 43 48 41 53 45 44 2E 20 C5 56 |EN PURCHASED. .V|
000050F0: 45 4E 20 57 48 45 4E 20 54 57 4F 20 44 49 46 46 |EN WHEN TWO DIFF|
00005100: 45 52 45 4E 54 20 53 59 53 54 45 4D 53 20 53 55 |ERENT SYSTEMS SU|
00005110: 50 50 4F 52 54 20 54 48 45 20 53 41 4D 45 0D 4C |PPORT THE SAME.L|
00005120: 41 4E 47 55 41 47 45 2C 20 49 54 20 49 53 20 55 |ANGUAGE, IT IS U|
00005130: 4E 52 45 41 4C 49 53 54 49 43 20 54 4F 20 45 58 |NREALISTIC TO EX|
00005140: 50 45 43 54 20 54 48 45 20 54 57 4F 20 49 4D 50 |PECT THE TWO IMP|
00005150: 4C 45 4D 45 4E 54 41 54 49 4F 4E 53 20 4F 46 20 |LEMENTATIONS OF |
00005160: 54 48 45 20 4C 41 4E 47 55 41 47 45 0D 54 4F 20 |THE LANGUAGE.TO |
00005170: 42 45 20 54 4F 54 41 4C 4C 59 20 43 4F 4D 50 41 |BE TOTALLY COMPA|
00005180: 54 49 42 4C 45 2E 20 C1 20 47 45 4E 45 52 41 4C |TIBLE. . GENERAL|
00005190: 20 50 55 52 50 4F 53 45 20 46 49 4C 45 20 54 52 | PURPOSE FILE TR|
000051A0: 41 4E 53 46 45 52 20 50 52 4F 54 4F 43 4F 4C 20 |ANSFER PROTOCOL |
000051B0: 53 48 4F 55 4C 44 20 4E 4F 54 0D 42 45 20 47 45 |SHOULD NOT.BE GE|
000051C0: 41 52 45 44 20 54 4F 57 41 52 44 53 20 54 48 45 |ARED TOWARDS THE|
000051D0: 20 46 45 41 54 55 52 45 53 20 41 4E 59 20 50 41 | FEATURES ANY PA|
000051E0: 52 54 49 43 55 4C 41 52 20 4C 41 4E 47 55 41 47 |RTICULAR LANGUAG|
000051F0: 45 2E 0D 0D 0D 0D CB C5 D2 CD C9 D4 0D 3D 3D 3D |E............===|
00005200: 3D 3D 3D 0D 0D CF 55 52 20 50 52 4F 54 4F 43 4F |===...UR PROTOCO|
00005210: 4C 2C 20 57 48 49 43 48 20 57 45 20 43 41 4C 4C |L, WHICH WE CALL|
00005220: 20 CB C5 D2 CD C9 D4 2C 20 41 44 44 52 45 53 53 | ......, ADDRESS|
00005230: 45 53 20 54 48 45 20 50 52 4F 42 4C 45 4D 53 20 |ES THE PROBLEMS |
00005240: 4F 55 54 4C 49 4E 45 44 20 41 42 4F 56 45 20 42 |OUTLINED ABOVE B|
00005250: 59 0D 53 45 54 54 49 4E 47 20 43 45 52 54 41 49 |Y.SETTING CERTAI|
00005260: 4E 20 4D 49 4E 49 4D 41 4C 20 53 54 41 4E 44 41 |N MINIMAL STANDA|
00005270: 52 44 53 20 46 4F 52 20 54 52 41 4E 53 4D 49 53 |RDS FOR TRANSMIS|
00005280: 53 49 4F 4E 2C 20 41 4E 44 20 50 52 4F 56 49 44 |SION, AND PROVID|
00005290: 49 4E 47 20 41 20 4D 41 50 50 49 4E 47 0D 42 45 |ING A MAPPING.BE|
000052A0: 54 57 45 45 4E 20 44 49 53 4B 20 53 54 4F 52 41 |TWEEN DISK STORA|
000052B0: 47 45 20 4F 52 47 41 4E 49 5A 41 54 49 4F 4E 2C |GE ORGANIZATION,|
000052C0: 20 4D 41 43 48 49 4E 45 20 57 4F 52 44 20 41 4E | MACHINE WORD AN|
000052D0: 44 20 42 59 54 45 20 53 49 5A 45 2C 20 41 4E 44 |D BYTE SIZE, AND|
000052E0: 20 54 48 45 20 54 52 41 4E 53 2D 0D 4D 49 53 53 | THE TRANS-.MISS|
000052F0: 49 4F 4E 20 4D 45 44 49 55 4D 2E 0D 0D CB C5 D2 |ION MEDIUM......|
00005300: CD C9 D4 20 48 41 53 20 54 48 45 20 46 4F 4C 4C |... HAS THE FOLL|
00005310: 4F 57 49 4E 47 20 43 48 41 52 41 43 54 45 52 49 |OWING CHARACTERI|
00005320: 53 54 49 43 53 3A 0D 0D C3 4F 4D 4D 55 4E 49 43 |STICS:...OMMUNIC|
00005330: 41 54 49 4F 4E 20 54 41 4B 45 53 20 50 4C 41 43 |ATION TAKES PLAC|
00005340: 45 20 4F 56 45 52 20 4F 52 44 49 4E 41 52 59 20 |E OVER ORDINARY |
00005350: 54 45 52 4D 49 4E 41 4C 20 43 4F 4E 4E 45 43 54 |TERMINAL CONNECT|
00005360: 49 4F 4E 53 2E 0D C3 4F 4D 4D 55 4E 49 43 41 54 |IONS...OMMUNICAT|
00005370: 49 4F 4E 20 49 53 20 48 41 4C 46 20 44 55 50 4C |ION IS HALF DUPL|
00005380: 45 58 2E 20 D4 48 49 53 20 41 4C 4C 4F 57 53 20 |EX. .HIS ALLOWS |
00005390: 42 4F 54 48 20 46 55 4C 4C 20 41 4E 44 20 48 41 |BOTH FULL AND HA|
000053A0: 4C 46 20 44 55 50 4C 45 58 20 53 59 53 54 45 4D |LF DUPLEX SYSTEM|
000053B0: 53 20 54 4F 0D 50 41 52 54 49 43 49 50 41 54 45 |S TO.PARTICIPATE|
000053C0: 2C 20 41 4E 44 20 49 54 20 45 4C 49 4D 49 4E 41 |, AND IT ELIMINA|
000053D0: 54 45 53 20 54 48 45 20 45 43 48 4F 49 4E 47 20 |TES THE ECHOING |
000053E0: 54 48 41 54 20 57 4F 55 4C 44 20 4F 54 48 45 52 |THAT WOULD OTHER|
000053F0: 57 49 53 45 20 4F 43 43 55 52 20 46 4F 52 0D 43 |WISE OCCUR FOR.C|
00005400: 48 41 52 41 43 54 45 52 53 20 41 52 52 49 56 49 |HARACTERS ARRIVI|
00005410: 4E 47 20 41 54 20 41 20 48 4F 53 54 20 4A 4F 42 |NG AT A HOST JOB|
00005420: 27 53 20 43 4F 4E 54 52 4F 4C 4C 49 4E 47 20 54 |'S CONTROLLING T|
00005430: 45 52 4D 49 4E 41 4C 2E 0D D4 48 45 20 50 41 43 |ERMINAL...HE PAC|
00005440: 4B 45 54 20 4C 45 4E 47 54 48 20 49 53 20 56 41 |KET LENGTH IS VA|
00005450: 52 49 41 42 4C 45 2C 20 42 55 54 20 54 48 45 20 |RIABLE, BUT THE |
00005460: 4D 41 58 49 4D 55 4D 20 49 53 20 39 36 20 43 48 |MAXIMUM IS 96 CH|
00005470: 41 52 41 43 54 45 52 53 20 53 4F 20 54 48 41 54 |ARACTERS SO THAT|
00005480: 20 4D 4F 53 54 0D 48 4F 53 54 53 20 43 41 4E 20 | MOST.HOSTS CAN |
00005490: 54 41 4B 45 20 50 41 43 4B 45 54 53 20 49 4E 20 |TAKE PACKETS IN |
000054A0: 57 49 54 48 4F 55 54 20 42 55 46 46 45 52 49 4E |WITHOUT BUFFERIN|
000054B0: 47 20 50 52 4F 42 4C 45 4D 53 2E 0D D0 41 43 4B |G PROBLEMS...ACK|
000054C0: 45 54 53 20 41 52 45 20 53 45 4E 54 20 49 4E 20 |ETS ARE SENT IN |
000054D0: 41 4C 54 45 52 4E 41 54 45 20 44 49 52 45 43 54 |ALTERNATE DIRECT|
000054E0: 49 4F 4E 53 3B 20 41 20 52 45 50 4C 59 20 49 53 |IONS; A REPLY IS|
000054F0: 20 52 45 51 55 49 52 45 44 20 46 4F 52 20 45 41 | REQUIRED FOR EA|
00005500: 43 48 20 50 41 43 4B 45 54 2E 0D D4 48 49 53 20 |CH PACKET...HIS |
00005510: 49 53 20 54 4F 20 41 4C 4C 4F 57 20 48 41 4C 46 |IS TO ALLOW HALF|
00005520: 20 44 55 50 4C 45 58 20 53 59 53 54 45 4D 53 20 | DUPLEX SYSTEMS |
00005530: 54 4F 20 50 41 52 54 49 43 49 50 41 54 45 2C 20 |TO PARTICIPATE, |
00005540: 41 4E 44 20 54 4F 20 50 52 45 56 45 4E 54 20 42 |AND TO PREVENT B|
00005550: 55 46 46 45 52 0D 4F 56 45 52 52 55 4E 53 20 54 |UFFER.OVERRUNS T|
00005560: 48 41 54 20 57 4F 55 4C 44 20 4F 43 43 55 52 20 |HAT WOULD OCCUR |
00005570: 4F 4E 20 53 4F 4D 45 20 53 59 53 54 45 4D 53 20 |ON SOME SYSTEMS |
00005580: 49 46 20 50 41 43 4B 45 54 53 20 57 45 52 45 20 |IF PACKETS WERE |
00005590: 53 45 4E 54 20 42 41 43 4B 20 54 4F 20 42 41 43 |SENT BACK TO BAC|
000055A0: 4B 2E 0D C1 20 54 49 4D 45 4F 55 54 20 46 41 43 |K... TIMEOUT FAC|
000055B0: 49 4C 49 54 59 2C 20 57 48 45 4E 20 41 56 41 49 |ILITY, WHEN AVAI|
000055C0: 4C 41 42 4C 45 2C 20 41 4C 4C 4F 57 53 20 54 52 |LABLE, ALLOWS TR|
000055D0: 41 4E 53 4D 49 53 53 49 4F 4E 20 54 4F 20 52 45 |ANSMISSION TO RE|
000055E0: 53 55 4D 45 20 41 46 54 45 52 20 4C 4F 53 54 0D |SUME AFTER LOST.|
000055F0: 50 41 43 4B 45 54 53 2E 0D C1 4C 4C 20 54 52 41 |PACKETS...LL TRA|
00005600: 4E 53 4D 49 53 53 49 4F 4E 20 49 53 20 49 4E 20 |NSMISSION IS IN |
00005610: C1 D3 C3 C9 C9 2E 20 20 C1 4E 59 20 4E 4F 4E 2D |...... .NY NON-|
00005620: C1 D3 C3 C9 C9 20 48 4F 53 54 53 20 41 52 45 20 |..... HOSTS ARE |
00005630: 52 45 53 50 4F 4E 53 49 42 4C 45 20 46 4F 52 0D |RESPONSIBLE FOR.|
00005640: 43 4F 4E 56 45 52 53 49 4F 4E 2E 20 20 C1 D3 C3 |CONVERSION. ...|
00005650: C9 C9 20 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 |.. CONTROL CHARA|
00005660: 43 54 45 52 53 20 41 52 45 20 50 52 45 46 49 58 |CTERS ARE PREFIX|
00005670: 45 44 20 41 4E 44 20 54 48 45 4E 20 43 4F 4E 56 |ED AND THEN CONV|
00005680: 45 52 54 45 44 20 54 4F 0D 50 52 49 4E 54 41 42 |ERTED TO.PRINTAB|
00005690: 4C 45 20 43 48 41 52 41 43 54 45 52 53 20 44 55 |LE CHARACTERS DU|
000056A0: 52 49 4E 47 20 54 52 41 4E 53 4D 49 53 53 49 4F |RING TRANSMISSIO|
000056B0: 4E 20 54 4F 20 45 4E 53 55 52 45 20 54 48 41 54 |N TO ENSURE THAT|
000056C0: 20 54 48 45 59 20 41 52 52 49 56 45 20 41 53 20 | THEY ARRIVE AS |
000056D0: 53 45 4E 54 2E 0D C1 20 53 49 4E 47 4C 45 20 C1 |SENT... SINGLE .|
000056E0: D3 C3 C9 C9 20 43 4F 4E 54 52 4F 4C 20 43 48 41 |.... CONTROL CHA|
000056F0: 52 41 43 54 45 52 20 28 4E 4F 52 4D 41 4C 4C 59 |RACTER (NORMALLY|
00005700: 20 D3 CF C8 29 20 49 53 20 55 53 45 44 20 54 4F | ...) IS USED TO|
00005710: 20 4D 41 52 4B 20 54 48 45 20 42 45 47 49 4E 4E | MARK THE BEGINN|
00005720: 49 4E 47 0D 4F 46 20 41 20 50 41 43 4B 45 54 2E |ING.OF A PACKET.|
00005730: 0D C2 49 4E 41 52 59 20 46 49 4C 45 53 20 43 41 |..INARY FILES CA|
00005740: 4E 20 42 45 20 54 52 41 4E 53 4D 49 54 54 45 44 |N BE TRANSMITTED|
00005750: 20 42 59 20 41 20 53 49 4D 49 4C 41 52 20 50 52 | BY A SIMILAR PR|
00005760: 45 46 49 58 20 53 43 48 45 4D 45 2C 20 4F 52 20 |EFIX SCHEME, OR |
00005770: 42 59 20 55 53 45 20 4F 46 20 54 48 45 0D 50 41 |BY USE OF THE.PA|
00005780: 52 49 54 59 20 42 49 54 20 57 48 45 4E 20 42 4F |RITY BIT WHEN BO|
00005790: 54 48 20 53 49 44 45 53 20 48 41 56 45 20 43 4F |TH SIDES HAVE CO|
000057A0: 4E 54 52 4F 4C 20 4F 46 20 49 54 2E 0D CC 4F 47 |NTROL OF IT...OG|
000057B0: 49 43 41 4C 20 52 45 43 4F 52 44 53 20 28 4C 49 |ICAL RECORDS (LI|
000057C0: 4E 45 53 29 20 49 4E 20 54 45 58 54 55 41 4C 20 |NES) IN TEXTUAL |
000057D0: 46 49 4C 45 53 20 41 52 45 20 54 45 52 4D 49 4E |FILES ARE TERMIN|
000057E0: 41 54 45 44 20 44 55 52 49 4E 47 20 54 52 41 4E |ATED DURING TRAN|
000057F0: 53 4D 49 53 53 49 4F 4E 0D 57 49 54 48 20 51 55 |SMISSION.WITH QU|
00005800: 4F 54 45 44 20 43 41 52 52 49 41 47 45 2D 52 45 |OTED CARRIAGE-RE|
00005810: 54 55 52 4E 2F 4C 49 4E 45 46 45 45 44 20 53 45 |TURN/LINEFEED SE|
00005820: 51 55 45 4E 43 45 53 2C 20 57 48 49 43 48 20 41 |QUENCES, WHICH A|
00005830: 52 45 20 54 52 41 4E 53 50 41 52 45 4E 54 20 54 |RE TRANSPARENT T|
00005840: 4F 20 54 48 45 0D 50 52 4F 54 4F 43 4F 4C 20 41 |O THE.PROTOCOL A|
00005850: 4E 44 20 4D 41 59 20 41 50 50 45 41 52 20 41 4E |ND MAY APPEAR AN|
00005860: 59 57 48 45 52 45 20 49 4E 20 41 20 50 41 43 4B |YWHERE IN A PACK|
00005870: 45 54 2E 20 20 D3 59 53 54 45 4D 53 20 54 48 41 |ET. .YSTEMS THA|
00005880: 54 20 44 45 4C 49 4D 49 54 20 52 45 43 4F 52 44 |T DELIMIT RECORD|
00005890: 53 0D 49 4E 20 4F 54 48 45 52 20 57 41 59 53 20 |S.IN OTHER WAYS |
000058A0: 41 52 45 20 52 45 53 50 4F 4E 53 49 42 4C 45 20 |ARE RESPONSIBLE |
000058B0: 46 4F 52 20 43 4F 4E 56 45 52 53 49 4F 4E 2C 20 |FOR CONVERSION, |
000058C0: 49 46 20 54 48 45 59 20 44 45 53 49 52 45 20 54 |IF THEY DESIRE T|
000058D0: 48 45 20 44 49 53 54 49 4E 43 54 49 4F 4E 0D 42 |HE DISTINCTION.B|
000058E0: 45 54 57 45 45 4E 20 52 45 43 4F 52 44 53 20 54 |ETWEEN RECORDS T|
000058F0: 4F 20 42 45 20 50 52 45 53 45 52 56 45 44 20 41 |O BE PRESERVED A|
00005900: 43 52 4F 53 53 20 55 4E 4C 49 4B 45 20 53 59 53 |CROSS UNLIKE SYS|
00005910: 54 45 4D 53 2E 0D CF 4E 4C 59 20 41 20 46 49 4C |TEMS...NLY A FIL|
00005920: 45 27 53 20 4E 41 4D 45 20 41 4E 44 20 43 4F 4E |E'S NAME AND CON|
00005930: 54 45 4E 54 53 20 41 52 45 20 54 52 41 4E 53 4D |TENTS ARE TRANSM|
00005940: 49 54 54 45 44 20 2D 20 4E 4F 20 41 54 54 52 49 |ITTED - NO ATTRI|
00005950: 42 55 54 45 53 2E 20 20 C9 54 20 49 53 20 54 48 |BUTES. .T IS TH|
00005960: 45 0D 55 53 45 52 27 53 20 52 45 53 50 4F 4E 53 |E.USER'S RESPONS|
00005970: 49 42 49 4C 49 54 59 20 54 4F 20 53 45 45 20 54 |IBILITY TO SEE T|
00005980: 48 41 54 20 54 48 45 20 46 49 4C 45 20 49 53 20 |HAT THE FILE IS |
00005990: 53 54 4F 52 45 44 20 43 4F 52 52 45 43 54 4C 59 |STORED CORRECTLY|
000059A0: 20 4F 4E 20 54 48 45 20 54 41 52 47 45 54 0D 53 | ON THE TARGET.S|
000059B0: 59 53 54 45 4D 2E 20 20 D7 49 54 48 49 4E 20 54 |YSTEM. .ITHIN T|
000059C0: 48 49 53 20 46 52 41 4D 45 57 4F 52 4B 2C 20 49 |HIS FRAMEWORK, I|
000059D0: 4E 56 45 52 54 49 42 4C 45 20 54 52 41 4E 53 46 |NVERTIBLE TRANSF|
000059E0: 45 52 20 4F 46 20 54 45 58 54 20 46 49 4C 45 53 |ER OF TEXT FILES|
000059F0: 20 43 41 4E 20 42 45 0D 41 53 53 55 52 45 44 2C | CAN BE.ASSURED,|
00005A00: 20 42 55 54 20 49 4E 56 45 52 54 49 42 4C 45 20 | BUT INVERTIBLE |
00005A10: 54 52 41 4E 53 46 45 52 20 4F 46 20 4E 4F 4E 2D |TRANSFER OF NON-|
00005A20: 40 5D 54 45 58 54 20 46 49 4C 45 53 20 44 45 50 |@]TEXT FILES DEP|
00005A30: 45 4E 44 53 20 4F 4E 20 54 48 45 0D 43 41 50 41 |ENDS ON THE.CAPA|
00005A40: 42 49 4C 49 54 49 45 53 20 4F 46 20 54 48 45 20 |BILITIES OF THE |
00005A50: 50 41 52 54 49 43 55 4C 41 52 20 49 4D 50 4C 45 |PARTICULAR IMPLE|
00005A60: 4D 45 4E 54 41 54 49 4F 4E 53 20 4F 46 20 CB C5 |MENTATIONS OF ..|
00005A70: D2 CD C9 D4 20 41 4E 44 20 54 48 45 20 48 4F 53 |.... AND THE HOS|
00005A80: 54 20 4F 50 45 52 41 54 49 4E 47 0D 53 59 53 54 |T OPERATING.SYST|
00005A90: 45 4D 53 2E 0D 0D CB C5 D2 CD C9 D4 20 48 41 53 |EMS......... HAS|
00005AA0: 20 4E 4F 20 53 50 45 43 49 41 4C 20 4B 4E 4F 57 | NO SPECIAL KNOW|
00005AB0: 4C 45 44 47 45 20 4F 46 20 54 48 45 20 48 4F 53 |LEDGE OF THE HOS|
00005AC0: 54 20 4F 4E 20 54 48 45 20 4F 54 48 45 52 20 53 |T ON THE OTHER S|
00005AD0: 49 44 45 2E 20 20 CE 4F 20 41 54 54 45 4D 50 54 |IDE. .O ATTEMPT|
00005AE0: 0D 49 53 20 4D 41 44 45 20 54 4F 20 22 49 4E 54 |.IS MADE TO "INT|
00005AF0: 45 47 52 41 54 45 22 20 54 48 45 20 54 57 4F 20 |EGRATE" THE TWO |
00005B00: 53 49 44 45 53 2E 20 20 D2 41 54 48 45 52 2C 20 |SIDES. .ATHER, |
00005B10: CB C5 D2 CD C9 D4 20 49 53 20 44 45 53 49 47 4E |...... IS DESIGN|
00005B20: 45 44 20 54 4F 20 57 4F 52 4B 20 4D 4F 52 45 0D |ED TO WORK MORE.|
00005B30: 4F 52 20 4C 45 53 53 20 55 4E 49 46 4F 52 4D 4C |OR LESS UNIFORML|
00005B40: 59 20 4F 4E 20 41 4C 4C 20 53 59 53 54 45 4D 53 |Y ON ALL SYSTEMS|
00005B50: 2E 20 CB C5 D2 CD C9 D4 20 4E 45 45 44 20 4E 4F |. ...... NEED NO|
00005B60: 54 20 42 45 20 57 52 49 54 54 45 4E 20 49 4E 20 |T BE WRITTEN IN |
00005B70: 41 4E 59 20 50 41 52 54 49 43 55 4C 41 52 0D 4C |ANY PARTICULAR.L|
00005B80: 41 4E 47 55 41 47 45 2E 20 C9 54 20 49 53 20 4E |ANGUAGE. .T IS N|
00005B90: 4F 54 20 41 20 50 4F 52 54 41 42 4C 45 20 50 52 |OT A PORTABLE PR|
00005BA0: 4F 47 52 41 4D 2C 20 42 55 54 20 41 20 50 4F 52 |OGRAM, BUT A POR|
00005BB0: 54 41 42 4C 45 20 50 52 4F 54 4F 43 4F 4C 2E 0D |TABLE PROTOCOL..|
00005BC0: 0D 0D D4 48 55 53 20 CB C5 D2 CD C9 D4 20 41 43 |...HUS ...... AC|
00005BD0: 43 4F 4D 4D 4F 44 41 54 45 53 20 49 54 53 45 4C |COMMODATES ITSEL|
00005BE0: 46 20 54 4F 20 4D 41 4E 59 20 53 59 53 54 45 4D |F TO MANY SYSTEM|
00005BF0: 53 20 42 59 20 43 4F 4E 46 4F 52 4D 49 4E 47 20 |S BY CONFORMING |
00005C00: 54 4F 20 41 20 43 4F 4D 4D 4F 4E 0D 53 55 42 53 |TO A COMMON.SUBS|
00005C10: 45 54 20 4F 46 20 54 48 45 49 52 20 46 45 41 54 |ET OF THEIR FEAT|
00005C20: 55 52 45 53 2E 20 20 C2 55 54 20 54 48 45 20 52 |URES. .UT THE R|
00005C30: 45 53 55 4C 54 49 4E 47 20 53 49 4D 50 4C 49 43 |ESULTING SIMPLIC|
00005C40: 49 54 59 20 41 4E 44 20 47 45 4E 45 52 41 4C 49 |ITY AND GENERALI|
00005C50: 54 59 20 41 4C 4C 4F 57 0D CB C5 D2 CD C9 D4 20 |TY ALLOW....... |
00005C60: 4F 4E 20 41 4E 59 20 4D 41 43 48 49 4E 45 20 54 |ON ANY MACHINE T|
00005C70: 4F 20 43 4F 4D 4D 55 4E 49 43 41 54 45 20 57 49 |O COMMUNICATE WI|
00005C80: 54 48 20 CB C5 D2 CD C9 D4 20 4F 4E 20 41 4E 59 |TH ...... ON ANY|
00005C90: 20 4F 54 48 45 52 20 4D 41 43 48 49 4E 45 2C 20 | OTHER MACHINE, |
00005CA0: 4D 49 43 52 4F 2D 0D 54 4F 2D 4D 41 49 4E 46 52 |MICRO-.TO-MAINFR|
00005CB0: 41 4D 45 2C 20 4D 49 43 52 4F 2D 54 4F 2D 4D 49 |AME, MICRO-TO-MI|
00005CC0: 43 52 4F 2C 20 4D 41 49 4E 46 52 41 4D 45 2D 54 |CRO, MAINFRAME-T|
00005CD0: 4F 2D 4D 41 49 4E 46 52 41 4D 45 2E 20 20 D4 48 |O-MAINFRAME. .H|
00005CE0: 45 20 42 41 43 4B 2D 41 4E 44 2D 46 4F 52 54 48 |E BACK-AND-FORTH|
00005CF0: 0D 45 58 43 48 41 4E 47 45 20 4F 46 20 50 41 43 |.EXCHANGE OF PAC|
00005D00: 4B 45 54 53 20 4B 45 45 50 53 20 54 48 45 20 54 |KETS KEEPS THE T|
00005D10: 57 4F 20 53 49 44 45 53 20 53 59 4E 43 48 52 4F |WO SIDES SYNCHRO|
00005D20: 4E 49 5A 45 44 3B 20 54 48 45 20 50 52 4F 54 4F |NIZED; THE PROTO|
00005D30: 43 4F 4C 20 43 41 4E 20 42 45 0D 43 41 4C 4C 45 |COL CAN BE.CALLE|
00005D40: 44 20 22 41 53 59 4E 43 48 52 4F 4E 4F 55 53 22 |D "ASYNCHRONOUS"|
00005D50: 20 4F 4E 4C 59 20 42 45 43 41 55 53 45 20 54 48 | ONLY BECAUSE TH|
00005D60: 45 20 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E 20 |E COMMUNICATION |
00005D70: 48 41 52 44 57 41 52 45 20 49 54 53 45 4C 46 20 |HARDWARE ITSELF |
00005D80: 4F 50 45 52 41 54 45 53 0D 41 53 59 4E 43 48 52 |OPERATES.ASYNCHR|
00005D90: 4F 4E 4F 55 53 4C 59 2E 20 C1 53 20 46 41 52 20 |ONOUSLY. .S FAR |
00005DA0: 41 53 20 54 48 45 20 55 53 45 52 20 49 53 20 43 |AS THE USER IS C|
00005DB0: 4F 4E 43 45 52 4E 45 44 2C 20 CB C5 D2 CD C9 D4 |ONCERNED, ......|
00005DC0: 20 49 53 20 41 20 44 4F 2D 49 54 2D 59 4F 55 52 | IS A DO-IT-YOUR|
00005DD0: 53 45 4C 46 0D 4F 50 45 52 41 54 49 4F 4E 2E 20 |SELF.OPERATION. |
00005DE0: C6 4F 52 20 49 4E 53 54 41 4E 43 45 2C 20 54 4F |.OR INSTANCE, TO|
00005DF0: 20 54 52 41 4E 53 46 45 52 20 46 49 4C 45 53 20 | TRANSFER FILES |
00005E00: 42 45 54 57 45 45 4E 20 59 4F 55 52 20 4D 49 43 |BETWEEN YOUR MIC|
00005E10: 52 4F 20 41 4E 44 20 41 20 4D 41 49 4E 46 52 41 |RO AND A MAINFRA|
00005E20: 4D 45 2C 0D 59 4F 55 20 57 4F 55 4C 44 20 52 55 |ME,.YOU WOULD RU|
00005E30: 4E 20 CB C5 D2 CD C9 D4 20 4F 4E 20 59 4F 55 52 |N ...... ON YOUR|
00005E40: 20 4D 49 43 52 4F 2C 20 50 55 54 20 CB C5 D2 CD | MICRO, PUT ....|
00005E50: C9 D4 20 49 4E 54 4F 20 54 45 52 4D 49 4E 41 4C |.. INTO TERMINAL|
00005E60: 20 45 4D 55 4C 41 54 49 4F 4E 20 4D 4F 44 45 2C | EMULATION MODE,|
00005E70: 0D 57 48 49 43 48 20 22 43 4F 4E 4E 45 43 54 53 |.WHICH "CONNECTS|
00005E80: 22 20 59 4F 55 20 54 4F 20 54 48 45 20 4D 41 49 |" YOU TO THE MAI|
00005E90: 4E 46 52 41 4D 45 2C 20 4C 4F 47 20 49 4E 20 41 |NFRAME, LOG IN A|
00005EA0: 4E 44 20 52 55 4E 20 CB C5 D2 CD C9 D4 20 4F 4E |ND RUN ...... ON|
00005EB0: 20 54 48 45 20 4D 41 49 4E 46 52 41 4D 45 2C 0D | THE MAINFRAME,.|
00005EC0: 54 48 45 4E 20 22 45 53 43 41 50 45 22 20 42 41 |THEN "ESCAPE" BA|
00005ED0: 43 4B 20 54 4F 20 54 48 45 20 4D 49 43 52 4F 20 |CK TO THE MICRO |
00005EE0: 41 4E 44 20 49 53 53 55 45 20 43 4F 4D 4D 41 4E |AND ISSUE COMMAN|
00005EF0: 44 53 20 54 4F 20 54 48 45 20 4D 49 43 52 4F 27 |DS TO THE MICRO'|
00005F00: 53 20 CB C5 D2 CD C9 D4 20 54 4F 0D 53 45 4E 44 |S ...... TO.SEND|
00005F10: 20 4F 52 20 46 45 54 43 48 20 54 48 45 20 44 45 | OR FETCH THE DE|
00005F20: 53 49 52 45 44 20 46 49 4C 45 53 2E 20 C1 4E 59 |SIRED FILES. .NY|
00005F30: 20 49 4E 43 4F 4E 56 45 4E 49 45 4E 43 45 20 49 | INCONVENIENCE I|
00005F40: 4D 50 4C 49 43 49 54 20 49 4E 20 54 48 49 53 20 |MPLICIT IN THIS |
00005F50: 50 52 4F 43 45 44 55 52 45 0D 49 53 20 41 20 43 |PROCEDURE.IS A C|
00005F60: 4F 4E 53 45 51 55 45 4E 43 45 20 4F 46 20 54 48 |ONSEQUENCE OF TH|
00005F70: 45 20 50 4F 57 45 52 20 49 54 20 47 49 56 45 53 |E POWER IT GIVES|
00005F80: 20 54 48 45 20 4F 52 44 49 4E 41 52 59 20 55 53 | THE ORDINARY US|
00005F90: 45 52 20 54 4F 20 45 53 54 41 42 4C 49 53 48 20 |ER TO ESTABLISH |
00005FA0: 52 45 4C 49 41 42 4C 45 0D 43 4F 4E 4E 45 43 54 |RELIABLE.CONNECT|
00005FB0: 49 4F 4E 53 20 42 45 54 57 45 45 4E 20 43 4F 4D |IONS BETWEEN COM|
00005FC0: 50 55 54 45 52 53 20 54 48 41 54 20 43 4F 55 4C |PUTERS THAT COUL|
00005FD0: 44 20 4E 4F 54 20 4F 54 48 45 52 57 49 53 45 20 |D NOT OTHERWISE |
00005FE0: 42 45 20 43 4F 4E 4E 45 43 54 45 44 2E 0D 0D D0 |BE CONNECTED....|
00005FF0: 41 43 4B 45 54 53 0D 3D 3D 3D 3D 3D 3D 3D 0D 0D |ACKETS.=======..|
00006000: CB C5 D2 CD C9 D4 20 50 41 43 4B 45 54 53 20 4E |...... PACKETS N|
00006010: 45 45 44 20 54 4F 20 43 4F 4E 54 41 49 4E 20 54 |EED TO CONTAIN T|
00006020: 48 45 20 44 41 54 41 20 54 48 41 54 20 49 53 20 |HE DATA THAT IS |
00006030: 42 45 49 4E 47 20 54 52 41 4E 53 46 45 52 52 45 |BEING TRANSFERRE|
00006040: 44 2C 20 50 4C 55 53 20 4D 49 4E 49 4D 55 4D 0D |D, PLUS MINIMUM.|
00006050: 49 4E 46 4F 52 4D 41 54 49 4F 4E 20 54 4F 20 41 |INFORMATION TO A|
00006060: 53 53 55 52 45 20 28 57 49 54 48 20 48 49 47 48 |SSURE (WITH HIGH|
00006070: 20 50 52 4F 42 41 42 49 4C 49 54 59 29 20 54 48 | PROBABILITY) TH|
00006080: 41 54 20 54 48 45 20 45 58 50 45 43 54 45 44 20 |AT THE EXPECTED |
00006090: 44 41 54 41 20 41 52 52 49 56 45 53 0D 43 4F 4D |DATA ARRIVES.COM|
000060A0: 50 4C 45 54 45 4C 59 20 41 4E 44 20 43 4F 52 52 |PLETELY AND CORR|
000060B0: 45 43 54 4C 59 2E 20 20 D3 45 56 45 52 41 4C 20 |ECTLY. .EVERAL |
000060C0: 49 53 53 55 45 53 20 43 4F 4D 45 20 55 50 20 57 |ISSUES COME UP W|
000060D0: 48 45 4E 20 44 45 53 49 47 4E 49 4E 47 20 54 48 |HEN DESIGNING TH|
000060E0: 45 20 50 41 43 4B 45 54 0D 4C 41 59 4F 55 54 3A |E PACKET.LAYOUT:|
000060F0: 20 48 4F 57 20 54 4F 20 52 45 50 52 45 53 45 4E | HOW TO REPRESEN|
00006100: 54 20 44 41 54 41 2C 20 48 4F 57 20 54 4F 20 44 |T DATA, HOW TO D|
00006110: 45 4C 49 4D 49 54 20 46 49 45 4C 44 53 20 57 49 |ELIMIT FIELDS WI|
00006120: 54 48 49 4E 20 54 48 45 20 50 41 43 4B 45 54 2C |THIN THE PACKET,|
00006130: 20 48 4F 57 20 54 4F 0D 44 45 4C 49 4D 49 54 20 | HOW TO.DELIMIT |
00006140: 54 48 45 20 50 41 43 4B 45 54 20 49 54 53 45 4C |THE PACKET ITSEL|
00006150: 46 2C 20 48 4F 57 20 54 4F 20 41 52 52 41 4E 47 |F, HOW TO ARRANG|
00006160: 45 20 54 48 45 20 46 49 45 4C 44 53 20 57 49 54 |E THE FIELDS WIT|
00006170: 48 49 4E 20 54 48 45 20 50 41 43 4B 45 54 2E 20 |HIN THE PACKET. |
00006180: 20 D3 49 4E 43 45 0D 54 48 45 20 54 52 41 4E 53 | .INCE.THE TRANS|
00006190: 4D 49 53 53 49 4F 4E 20 4D 45 44 49 55 4D 20 49 |MISSION MEDIUM I|
000061A0: 54 53 45 4C 46 20 49 53 20 43 48 41 52 41 43 54 |TSELF IS CHARACT|
000061B0: 45 52 2D 4F 52 49 45 4E 54 45 44 2C 20 49 54 20 |ER-ORIENTED, IT |
000061C0: 49 53 20 4E 4F 54 20 46 45 41 53 49 42 4C 45 20 |IS NOT FEASIBLE |
000061D0: 54 4F 0D 54 52 41 4E 53 4D 49 54 20 42 49 54 20 |TO.TRANSMIT BIT |
000061E0: 53 54 52 49 4E 47 53 20 4F 46 20 41 52 42 49 54 |STRINGS OF ARBIT|
000061F0: 52 41 52 59 20 4C 45 4E 47 54 48 2C 20 41 53 20 |RARY LENGTH, AS |
00006200: 44 4F 20 54 48 45 20 42 49 54 2D 4F 52 49 45 4E |DO THE BIT-ORIEN|
00006210: 54 45 44 20 50 52 4F 54 4F 43 4F 4C 53 0D 4C 49 |TED PROTOCOLS.LI|
00006220: 4B 45 20 C8 C4 CC C3 20 41 4E 44 20 D3 C4 CC C3 |KE .... AND ....|
00006230: 2E 20 20 D4 48 45 52 45 46 4F 52 45 20 54 48 45 |. .HEREFORE THE|
00006240: 20 53 4D 41 4C 4C 45 53 54 20 55 4E 49 54 20 4F | SMALLEST UNIT O|
00006250: 46 20 49 4E 46 4F 52 4D 41 54 49 4F 4E 20 49 4E |F INFORMATION IN|
00006260: 20 41 20 50 41 43 4B 45 54 0D 4D 55 53 54 20 42 | A PACKET.MUST B|
00006270: 45 20 54 48 45 20 C1 D3 C3 C9 C9 20 43 48 41 52 |E THE ..... CHAR|
00006280: 41 43 54 45 52 2E 20 20 C1 53 20 57 45 20 57 49 |ACTER. .S WE WI|
00006290: 4C 4C 20 53 45 45 2C 20 54 48 49 53 20 50 52 45 |LL SEE, THIS PRE|
000062A0: 43 4C 55 44 45 53 20 53 4F 4D 45 20 54 45 43 48 |CLUDES SOME TECH|
000062B0: 4E 49 51 55 45 53 0D 54 48 41 54 20 41 52 45 20 |NIQUES.THAT ARE |
000062C0: 55 53 45 44 20 57 49 54 48 20 4F 54 48 45 52 20 |USED WITH OTHER |
000062D0: 43 4F 4D 4D 55 4E 49 43 41 54 49 4F 4E 20 4D 45 |COMMUNICATION ME|
000062E0: 44 49 41 2E 0D 0D C3 4F 4E 54 52 4F 4C 20 C6 49 |DIA....ONTROL .I|
000062F0: 45 4C 44 53 0D 0D CD 4F 53 54 20 50 4F 50 55 4C |ELDS...OST POPUL|
00006300: 41 52 20 50 52 4F 54 4F 43 4F 4C 20 44 45 46 49 |AR PROTOCOL DEFI|
00006310: 4E 49 54 49 4F 4E 53 20 56 49 45 57 20 54 48 45 |NITIONS VIEW THE|
00006320: 20 50 41 43 4B 45 54 20 41 53 20 4C 41 59 45 52 | PACKET AS LAYER|
00006330: 53 20 4F 46 20 49 4E 46 4F 52 4D 41 54 49 4F 4E |S OF INFORMATION|
00006340: 2C 0D 57 48 49 43 48 20 50 41 53 53 20 54 48 52 |,.WHICH PASS THR|
00006350: 4F 55 47 48 20 41 20 48 49 45 52 41 52 43 48 59 |OUGH A HIERARCHY|
00006360: 20 4F 46 20 50 52 4F 54 4F 43 4F 4C 20 4C 45 56 | OF PROTOCOL LEV|
00006370: 45 4C 53 2C 20 45 41 43 48 20 4C 45 56 45 4C 20 |ELS, EACH LEVEL |
00006380: 41 44 44 49 4E 47 20 49 54 53 20 4F 57 4E 0D 49 |ADDING ITS OWN.I|
00006390: 4E 46 4F 52 4D 41 54 49 4F 4E 20 41 54 20 54 48 |NFORMATION AT TH|
000063A0: 45 20 45 4E 44 53 20 4F 46 20 41 4E 20 4F 55 54 |E ENDS OF AN OUT|
000063B0: 42 4F 55 4E 44 20 50 41 43 4B 45 54 20 4F 52 20 |BOUND PACKET OR |
000063C0: 53 54 52 49 50 50 49 4E 47 20 49 54 53 20 49 4E |STRIPPING ITS IN|
000063D0: 46 4F 52 4D 41 54 49 4F 4E 20 46 52 4F 4D 0D 54 |FORMATION FROM.T|
000063E0: 48 45 20 45 4E 44 53 20 4F 46 20 41 4E 20 49 4E |HE ENDS OF AN IN|
000063F0: 43 4F 4D 49 4E 47 20 50 41 43 4B 45 54 2C 20 41 |COMING PACKET, A|
00006400: 4E 44 20 54 48 45 4E 20 50 41 53 53 49 4E 47 20 |ND THEN PASSING |
00006410: 54 48 45 20 52 45 53 55 4C 54 20 41 4C 4F 4E 47 |THE RESULT ALONG|
00006420: 20 54 4F 20 54 48 45 20 4E 45 58 54 0D 4C 45 56 | TO THE NEXT.LEV|
00006430: 45 4C 20 49 4E 20 54 48 45 20 48 49 45 52 41 52 |EL IN THE HIERAR|
00006440: 43 48 59 2E 20 D4 48 45 20 46 49 45 4C 44 53 20 |CHY. .HE FIELDS |
00006450: 46 4F 52 20 45 41 43 48 20 4C 41 59 45 52 20 4D |FOR EACH LAYER M|
00006460: 55 53 54 20 42 45 20 41 52 52 41 4E 47 45 44 20 |UST BE ARRANGED |
00006470: 53 4F 20 54 48 41 54 20 54 48 45 59 0D 43 41 4E |SO THAT THEY.CAN|
00006480: 20 42 45 20 46 4F 55 4E 44 2C 20 49 44 45 4E 54 | BE FOUND, IDENT|
00006490: 49 46 49 45 44 2C 20 41 4E 44 20 49 4E 54 45 52 |IFIED, AND INTER|
000064A0: 50 52 45 54 45 44 20 43 4F 52 52 45 43 54 4C 59 |PRETED CORRECTLY|
000064B0: 20 41 54 20 54 48 45 20 41 50 50 52 4F 50 52 49 | AT THE APPROPRI|
000064C0: 41 54 45 20 4C 45 56 45 4C 2E 0D 0D D3 49 4E 43 |ATE LEVEL....INC|
000064D0: 45 20 CB C5 D2 CD C9 D4 20 50 41 43 4B 45 54 53 |E ...... PACKETS|
000064E0: 20 41 52 45 20 53 48 4F 52 54 2C 20 49 54 20 49 | ARE SHORT, IT I|
000064F0: 53 20 49 4D 50 4F 52 54 41 4E 54 20 54 4F 20 4D |S IMPORTANT TO M|
00006500: 49 4E 49 4D 49 5A 45 20 54 48 45 20 41 4D 4F 55 |INIMIZE THE AMOU|
00006510: 4E 54 20 4F 46 0D 43 4F 4E 54 52 4F 4C 20 49 4E |NT OF.CONTROL IN|
00006520: 46 4F 52 4D 41 54 49 4F 4E 20 50 45 52 20 50 41 |FORMATION PER PA|
00006530: 43 4B 45 54 2E 20 20 C9 54 20 57 4F 55 4C 44 20 |CKET. .T WOULD |
00006540: 42 45 20 43 4F 4E 56 45 4E 49 45 4E 54 20 54 4F |BE CONVENIENT TO|
00006550: 20 4C 49 4D 49 54 20 54 48 45 20 43 4F 4E 54 52 | LIMIT THE CONTR|
00006560: 4F 4C 0D 46 49 45 4C 44 53 20 54 4F 20 4F 4E 45 |OL.FIELDS TO ONE|
00006570: 20 43 48 41 52 41 43 54 45 52 20 45 41 43 48 2E | CHARACTER EACH.|
00006580: 20 20 D3 49 4E 43 45 20 57 45 20 48 41 56 45 20 | .INCE WE HAVE |
00006590: 39 35 20 50 52 49 4E 54 41 42 4C 45 20 43 48 41 |95 PRINTABLE CHA|
000065A0: 52 41 43 54 45 52 53 20 54 4F 20 57 4F 52 4B 0D |RACTERS TO WORK.|
000065B0: 57 49 54 48 20 28 31 32 38 20 C1 D3 C3 C9 C9 20 |WITH (128 ..... |
000065C0: 43 48 41 52 41 43 54 45 52 53 2C 20 4C 45 53 53 |CHARACTERS, LESS|
000065D0: 20 C4 C5 CC 20 41 4E 44 20 54 48 45 20 33 32 20 | ... AND THE 32 |
000065E0: 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 43 54 45 |CONTROL CHARACTE|
000065F0: 52 53 29 2C 20 57 45 20 43 41 4E 0D 52 45 50 52 |RS), WE CAN.REPR|
00006600: 45 53 45 4E 54 20 56 41 4C 55 45 53 20 46 52 4F |ESENT VALUES FRO|
00006610: 4D 20 30 20 54 4F 20 39 34 20 57 49 54 48 20 41 |M 0 TO 94 WITH A|
00006620: 20 53 49 4E 47 4C 45 20 43 48 41 52 41 43 54 45 | SINGLE CHARACTE|
00006630: 52 2E 0D 0D D4 48 45 20 50 41 43 4B 45 54 20 53 |R....HE PACKET S|
00006640: 45 51 55 45 4E 43 45 20 4E 55 4D 42 45 52 20 49 |EQUENCE NUMBER I|
00006650: 53 20 55 53 45 44 20 54 4F 20 44 45 54 45 43 54 |S USED TO DETECT|
00006660: 20 4D 49 53 53 49 4E 47 20 4F 52 20 44 55 50 4C | MISSING OR DUPL|
00006670: 49 43 41 54 45 20 50 41 43 4B 45 54 53 2E 0D C9 |ICATE PACKETS...|
00006680: 54 20 49 53 20 55 4E 4C 49 4B 45 4C 59 20 54 48 |T IS UNLIKELY TH|
00006690: 41 54 20 41 20 4C 41 52 47 45 20 4E 55 4D 42 45 |AT A LARGE NUMBE|
000066A0: 52 20 4F 46 20 50 41 43 4B 45 54 53 20 43 4F 55 |R OF PACKETS COU|
000066B0: 4C 44 20 42 45 20 4C 4F 53 54 2C 20 45 53 50 45 |LD BE LOST, ESPE|
000066C0: 43 49 41 4C 4C 59 20 53 49 4E 43 45 0D 50 41 43 |CIALLY SINCE.PAC|
000066D0: 4B 45 54 20 4E 20 49 53 20 41 43 4B 4E 4F 57 4C |KET N IS ACKNOWL|
000066E0: 45 44 47 45 44 20 42 45 46 4F 52 45 20 50 41 43 |EDGED BEFORE PAC|
000066F0: 4B 45 54 20 4E 2B 31 20 49 53 20 53 45 4E 54 2E |KET N+1 IS SENT.|
00006700: 20 D3 4F 20 54 48 45 20 53 45 51 55 45 4E 43 45 | .O THE SEQUENCE|
00006710: 20 4E 55 4D 42 45 52 20 43 41 4E 0D 42 45 20 41 | NUMBER CAN.BE A|
00006720: 20 53 4D 41 4C 4C 20 51 55 41 4E 54 49 54 59 2C | SMALL QUANTITY,|
00006730: 20 57 48 49 43 48 20 22 57 52 41 50 53 20 41 52 | WHICH "WRAPS AR|
00006740: 4F 55 4E 44 22 20 54 4F 20 49 54 53 20 4D 49 4E |OUND" TO ITS MIN|
00006750: 49 4D 55 4D 20 56 41 4C 55 45 20 57 48 45 4E 20 |IMUM VALUE WHEN |
00006760: 49 54 20 45 58 43 45 45 44 53 0D 41 20 53 50 45 |IT EXCEEDS.A SPE|
00006770: 43 49 46 49 45 44 20 4D 41 58 49 4D 55 4D 20 56 |CIFIED MAXIMUM V|
00006780: 41 4C 55 45 2E 20 D4 4F 20 50 52 45 56 45 4E 54 |ALUE. .O PREVENT|
00006790: 20 4C 4F 4E 47 20 50 41 43 4B 45 54 53 2C 20 41 | LONG PACKETS, A|
000067A0: 20 53 4D 41 4C 4C 20 4D 41 58 49 4D 55 4D 20 4C | SMALL MAXIMUM L|
000067B0: 45 4E 47 54 48 20 43 41 4E 0D 42 45 20 45 4E 46 |ENGTH CAN.BE ENF|
000067C0: 4F 52 43 45 44 20 42 59 20 53 50 45 43 49 46 59 |ORCED BY SPECIFY|
000067D0: 49 4E 47 20 54 48 45 20 50 41 43 4B 45 54 20 4C |ING THE PACKET L|
000067E0: 45 4E 47 54 48 20 57 49 54 48 20 41 20 53 49 4E |ENGTH WITH A SIN|
000067F0: 47 4C 45 20 43 48 41 52 41 43 54 45 52 3B 20 53 |GLE CHARACTER; S|
00006800: 49 4E 43 45 0D 54 48 45 52 45 20 41 52 45 20 39 |INCE.THERE ARE 9|
00006810: 35 20 50 52 49 4E 54 41 42 4C 45 20 C1 D3 C3 C9 |5 PRINTABLE ....|
00006820: C9 20 43 48 41 52 41 43 54 45 52 53 2C 20 54 48 |. CHARACTERS, TH|
00006830: 49 53 20 57 4F 55 4C 44 20 42 45 20 54 48 45 20 |IS WOULD BE THE |
00006840: 4D 41 58 49 4D 55 4D 20 4C 45 4E 47 54 48 2C 0D |MAXIMUM LENGTH,.|
00006850: 44 45 50 45 4E 44 49 4E 47 20 4F 4E 20 48 4F 57 |DEPENDING ON HOW|
00006860: 20 57 45 20 43 4F 55 4E 54 20 54 48 45 20 43 4F | WE COUNT THE CO|
00006870: 4E 54 52 4F 4C 20 46 49 45 4C 44 53 2E 0D 0D D4 |NTROL FIELDS....|
00006880: 48 45 20 43 48 45 43 4B 53 55 4D 20 43 41 4E 20 |HE CHECKSUM CAN |
00006890: 42 45 20 4F 46 20 46 49 58 45 44 20 4C 45 4E 47 |BE OF FIXED LENG|
000068A0: 54 48 2E 20 20 D4 48 45 20 41 43 54 55 41 4C 20 |TH. .HE ACTUAL |
000068B0: 4C 45 4E 47 54 48 20 44 45 50 45 4E 44 53 20 4F |LENGTH DEPENDS O|
000068C0: 4E 20 54 48 45 20 44 45 53 49 52 45 44 0D 42 41 |N THE DESIRED.BA|
000068D0: 4C 41 4E 43 45 20 42 45 54 57 45 45 4E 20 41 4E |LANCE BETWEEN AN|
000068E0: 44 20 45 46 46 49 43 49 45 4E 43 59 20 41 4E 44 |D EFFICIENCY AND|
000068F0: 20 45 52 52 4F 52 20 44 45 54 45 43 54 49 4F 4E | ERROR DETECTION|
00006900: 2E 0D 0D D4 48 45 20 50 41 43 4B 45 54 20 4C 45 |....HE PACKET LE|
00006910: 4E 47 54 48 20 41 4E 44 20 43 48 45 43 4B 53 55 |NGTH AND CHECKSU|
00006920: 4D 20 41 43 54 20 54 4F 47 45 54 48 45 52 20 54 |M ACT TOGETHER T|
00006930: 4F 20 44 45 54 45 43 54 20 43 4F 52 52 55 50 54 |O DETECT CORRUPT|
00006940: 45 44 2C 20 4D 49 53 53 49 4E 47 2C 20 4F 52 0D |ED, MISSING, OR.|
00006950: 45 58 54 52 41 20 43 48 41 52 41 43 54 45 52 53 |EXTRA CHARACTERS|
00006960: 2E 20 20 D4 48 45 53 45 20 41 52 45 20 54 48 45 |. .HESE ARE THE|
00006970: 20 45 53 53 45 4E 54 49 41 4C 20 46 49 45 4C 44 | ESSENTIAL FIELD|
00006980: 53 20 46 4F 52 20 50 52 4F 4D 4F 54 49 4E 47 20 |S FOR PROMOTING |
00006990: 45 52 52 4F 52 2D 46 52 45 45 0D 54 52 41 4E 53 |ERROR-FREE.TRANS|
000069A0: 4D 49 53 53 49 4F 4E 2E 20 C2 55 54 20 53 4F 20 |MISSION. .UT SO |
000069B0: 46 41 52 2C 20 57 45 27 56 45 20 4F 4E 4C 59 20 |FAR, WE'VE ONLY |
000069C0: 43 4F 4E 53 49 44 45 52 45 44 20 50 41 43 4B 45 |CONSIDERED PACKE|
000069D0: 54 53 20 54 48 41 54 20 43 41 52 52 59 20 41 43 |TS THAT CARRY AC|
000069E0: 54 55 41 4C 20 46 49 4C 45 0D 44 41 54 41 3B 20 |TUAL FILE.DATA; |
000069F0: 57 45 20 57 49 4C 4C 20 41 4C 53 4F 20 52 45 51 |WE WILL ALSO REQ|
00006A00: 55 49 52 45 20 53 50 45 43 49 41 4C 20 50 41 43 |UIRE SPECIAL PAC|
00006A10: 4B 45 54 53 20 43 4F 4D 50 4F 53 45 44 20 4F 4E |KETS COMPOSED ON|
00006A20: 4C 59 20 4F 46 20 43 4F 4E 54 52 4F 4C 20 49 4E |LY OF CONTROL IN|
00006A30: 46 4F 52 4D 41 2D 0D 54 49 4F 4E 2C 20 46 4F 52 |FORMA-.TION, FOR|
00006A40: 20 49 4E 53 54 41 4E 43 45 20 54 4F 20 54 45 4C | INSTANCE TO TEL|
00006A50: 4C 20 54 48 45 20 52 45 4D 4F 54 45 20 48 4F 53 |L THE REMOTE HOS|
00006A60: 54 20 54 48 45 20 4E 41 4D 45 20 4F 46 20 54 48 |T THE NAME OF TH|
00006A70: 45 20 46 49 4C 45 20 54 48 41 54 20 49 53 20 41 |E FILE THAT IS A|
00006A80: 42 4F 55 54 0D 54 4F 20 43 4F 4D 45 2C 20 4F 52 |BOUT.TO COME, OR|
00006A90: 20 54 4F 20 54 45 4C 4C 20 49 54 20 54 48 41 54 | TO TELL IT THAT|
00006AA0: 20 54 48 45 20 54 52 41 4E 53 4D 49 53 53 49 4F | THE TRANSMISSIO|
00006AB0: 4E 20 49 53 20 43 4F 4D 50 4C 45 54 45 2E 20 20 |N IS COMPLETE. |
00006AC0: D4 48 49 53 20 43 41 4E 20 42 45 0D 41 43 43 4F |.HIS CAN BE.ACCO|
00006AD0: 4D 50 4C 49 53 48 45 44 20 57 49 54 48 20 41 20 |MPLISHED WITH A |
00006AE0: 50 41 43 4B 45 54 20 54 59 50 45 20 46 49 45 4C |PACKET TYPE FIEL|
00006AF0: 44 2E 20 20 D4 48 45 20 4E 55 4D 42 45 52 20 4F |D. .HE NUMBER O|
00006B00: 46 20 46 55 4E 43 54 49 4F 4E 53 20 57 45 20 4E |F FUNCTIONS WE N|
00006B10: 45 45 44 20 54 4F 0D 53 50 45 43 49 46 59 20 49 |EED TO.SPECIFY I|
00006B20: 4E 20 54 48 49 53 20 46 49 45 4C 44 20 49 53 20 |N THIS FIELD IS |
00006B30: 53 4D 41 4C 4C 2C 20 53 4F 20 41 20 53 49 4E 47 |SMALL, SO A SING|
00006B40: 4C 45 20 43 48 41 52 41 43 54 45 52 20 43 41 4E |LE CHARACTER CAN|
00006B50: 20 53 55 46 46 49 43 45 20 48 45 52 45 20 54 4F | SUFFICE HERE TO|
00006B60: 4F 2E 0D 0D D0 41 43 4B 45 54 20 C6 52 41 4D 49 |O....ACKET .RAMI|
00006B70: 4E 47 0D 0D D7 45 20 43 48 4F 4F 53 45 20 54 4F |NG...E CHOOSE TO|
00006B80: 20 4D 41 52 4B 20 54 48 45 20 42 45 47 49 4E 4E | MARK THE BEGINN|
00006B90: 49 4E 47 20 4F 46 20 41 20 50 41 43 4B 45 54 20 |ING OF A PACKET |
00006BA0: 57 49 54 48 20 41 20 44 49 53 54 49 4E 47 55 49 |WITH A DISTINGUI|
00006BB0: 53 48 45 44 20 53 54 41 52 54 0D 43 48 41 52 41 |SHED START.CHARA|
00006BC0: 43 54 45 52 2C 20 D3 CF C8 20 28 D3 54 41 52 54 |CTER, ... (.TART|
00006BD0: 20 CF 46 20 C8 45 41 44 45 52 2C 20 C1 D3 C3 C9 | .F .EADER, ....|
00006BE0: C9 20 31 2C 20 C3 4F 4E 54 52 4F 4C 2D C1 29 2E |. 1, .ONTROL-.).|
00006BF0: 20 20 D4 48 49 53 20 43 48 41 52 41 43 54 45 52 | .HIS CHARACTER|
00006C00: 20 43 41 4E 4E 4F 54 0D 41 50 50 45 41 52 20 41 | CANNOT.APPEAR A|
00006C10: 4E 59 57 48 45 52 45 20 45 4C 53 45 20 57 49 54 |NYWHERE ELSE WIT|
00006C20: 48 49 4E 20 54 48 45 20 50 41 43 4B 45 54 2E 20 |HIN THE PACKET. |
00006C30: 20 D3 CF C8 20 57 41 53 20 43 48 4F 53 45 4E 20 | ... WAS CHOSEN |
00006C40: 42 45 43 41 55 53 45 2C 20 55 4E 4C 49 4B 45 20 |BECAUSE, UNLIKE |
00006C50: 4D 4F 53 54 0D 4F 54 48 45 52 20 43 4F 4E 54 52 |MOST.OTHER CONTR|
00006C60: 4F 4C 20 43 48 41 52 41 43 54 45 52 53 2C 20 49 |OL CHARACTERS, I|
00006C70: 54 20 49 53 20 47 45 4E 45 52 41 4C 4C 59 20 41 |T IS GENERALLY A|
00006C80: 43 43 45 50 54 45 44 20 55 50 4F 4E 20 49 4E 50 |CCEPTED UPON INP|
00006C90: 55 54 20 41 54 20 41 20 4A 4F 42 27 53 0D 43 4F |UT AT A JOB'S.CO|
00006CA0: 4E 54 52 4F 4C 4C 49 4E 47 20 54 45 52 4D 49 4E |NTROLLING TERMIN|
00006CB0: 41 4C 20 41 53 20 41 20 44 41 54 41 20 43 48 41 |AL AS A DATA CHA|
00006CC0: 52 41 43 54 45 52 2C 20 52 41 54 48 45 52 20 54 |RACTER, RATHER T|
00006CD0: 48 41 4E 20 41 4E 20 49 4E 54 45 52 52 55 50 54 |HAN AN INTERRUPT|
00006CE0: 20 4F 52 20 42 52 45 41 4B 0D 43 48 41 52 41 43 | OR BREAK.CHARAC|
00006CF0: 54 45 52 20 4F 4E 20 4D 4F 53 54 20 4D 41 49 4E |TER ON MOST MAIN|
00006D00: 46 52 41 4D 45 53 2E 20 20 D4 48 49 53 20 49 53 |FRAMES. .HIS IS|
00006D10: 20 50 52 4F 42 41 42 4C 59 20 4E 4F 20 41 43 43 | PROBABLY NO ACC|
00006D20: 49 44 45 4E 54 2C 20 53 49 4E 43 45 20 49 54 20 |IDENT, SINCE IT |
00006D30: 57 41 53 0D 4F 52 49 47 49 4E 41 4C 4C 59 20 49 |WAS.ORIGINALLY I|
00006D40: 4E 54 45 4E 44 45 44 20 46 4F 52 20 54 48 49 53 |NTENDED FOR THIS|
00006D50: 20 55 53 45 20 42 59 20 54 48 45 20 44 45 53 49 | USE BY THE DESI|
00006D60: 47 4E 45 52 53 20 4F 46 20 54 48 45 20 C1 D3 C3 |GNERS OF THE ...|
00006D70: C9 C9 20 41 4C 50 48 41 42 45 54 2E 0D D3 48 4F |.. ALPHABET...HO|
00006D80: 55 4C 44 20 41 20 53 59 53 54 45 4D 20 42 45 20 |ULD A SYSTEM BE |
00006D90: 49 4E 43 41 50 41 42 4C 45 20 4F 46 20 53 45 4E |INCAPABLE OF SEN|
00006DA0: 44 49 4E 47 20 4F 52 20 52 45 43 45 49 56 49 4E |DING OR RECEIVIN|
00006DB0: 47 20 D3 CF C8 2C 20 49 54 20 49 53 20 50 4F 53 |G ..., IT IS POS|
00006DC0: 53 49 42 4C 45 20 54 4F 0D 52 45 44 45 46 49 4E |SIBLE TO.REDEFIN|
00006DD0: 45 20 54 48 45 20 53 54 41 52 54 2D 4F 46 2D 50 |E THE START-OF-P|
00006DE0: 41 43 4B 45 54 20 43 48 41 52 41 43 54 45 52 20 |ACKET CHARACTER |
00006DF0: 54 4F 20 42 45 20 41 4E 59 20 4F 54 48 45 52 20 |TO BE ANY OTHER |
00006E00: 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 43 54 45 |CONTROL CHARACTE|
00006E10: 52 3B 20 54 48 45 0D 54 57 4F 20 53 49 44 45 53 |R; THE.TWO SIDES|
00006E20: 20 4E 45 45 44 20 4E 4F 54 20 55 53 45 20 54 48 | NEED NOT USE TH|
00006E30: 45 20 53 41 4D 45 20 4F 4E 45 2E 20 D4 48 45 52 |E SAME ONE. .HER|
00006E40: 45 20 41 52 45 20 54 48 52 45 45 20 50 52 49 4E |E ARE THREE PRIN|
00006E50: 43 49 50 41 4C 20 4F 50 54 49 4F 4E 53 20 46 4F |CIPAL OPTIONS FO|
00006E60: 52 0D 52 45 43 4F 47 4E 49 5A 49 4E 47 20 54 48 |R.RECOGNIZING TH|
00006E70: 45 20 45 4E 44 20 4F 46 20 41 20 50 41 43 4B 45 |E END OF A PACKE|
00006E80: 54 3A 0D 0D 41 20 46 49 58 45 44 20 4C 45 4E 47 |T:..A FIXED LENG|
00006E90: 54 48 2C 20 41 20 44 49 53 54 49 4E 47 55 49 53 |TH, A DISTINGUIS|
00006EA0: 48 45 44 20 50 41 43 4B 45 54 2D 45 4E 44 20 43 |HED PACKET-END C|
00006EB0: 48 41 52 41 43 54 45 52 2C 20 41 4E 44 20 41 20 |HARACTER, AND A |
00006EC0: 4C 45 4E 47 54 48 20 46 49 45 4C 44 2E 0D D4 48 |LENGTH FIELD...H|
00006ED0: 45 52 45 20 41 52 45 20 41 52 47 55 4D 45 4E 54 |ERE ARE ARGUMENT|
00006EE0: 53 20 46 4F 52 20 41 4E 44 20 41 47 41 49 4E 53 |S FOR AND AGAINS|
00006EF0: 54 20 45 41 43 48 20 49 4E 56 4F 4C 56 49 4E 47 |T EACH INVOLVING|
00006F00: 20 57 48 41 54 20 48 41 50 50 45 4E 53 20 57 48 | WHAT HAPPENS WH|
00006F10: 45 4E 20 43 48 41 52 41 43 2D 0D 54 45 52 53 2C |EN CHARAC-.TERS,|
00006F20: 20 50 41 52 54 49 43 55 4C 41 52 4C 59 20 41 20 | PARTICULARLY A |
00006F30: 4C 45 4E 47 54 48 20 4F 52 20 54 45 52 4D 49 4E |LENGTH OR TERMIN|
00006F40: 41 54 4F 52 2C 20 49 53 20 4C 4F 53 54 20 4F 52 |ATOR, IS LOST OR|
00006F50: 20 47 41 52 42 4C 45 44 2C 20 57 48 49 43 48 20 | GARBLED, WHICH |
00006F60: 57 49 4C 4C 20 42 45 0D 4D 45 4E 54 49 4F 4E 45 |WILL BE.MENTIONE|
00006F70: 44 20 4C 41 54 45 52 2E 20 20 CB C5 D2 CD C9 D4 |D LATER. ......|
00006F80: 20 55 53 45 53 20 41 20 4C 45 4E 47 54 48 20 46 | USES A LENGTH F|
00006F90: 49 45 4C 44 2E 20 D4 4F 20 54 41 4B 45 20 49 4E |IELD. .O TAKE IN|
00006FA0: 20 41 20 50 41 43 4B 45 54 2C 20 41 20 CB C5 D2 | A PACKET, A ...|
00006FB0: CD C9 D4 0D 50 52 4F 47 52 41 4D 20 47 45 54 53 |....PROGRAM GETS|
00006FC0: 20 43 48 41 52 41 43 54 45 52 53 20 46 52 4F 4D | CHARACTERS FROM|
00006FD0: 20 54 48 45 20 4C 49 4E 45 20 55 4E 54 49 4C 20 | THE LINE UNTIL |
00006FE0: 49 54 20 45 4E 43 4F 55 4E 54 45 52 53 20 54 48 |IT ENCOUNTERS TH|
00006FF0: 45 20 D3 CF C8 2E 20 20 D4 48 45 20 4E 45 58 54 |E .... .HE NEXT|
00007000: 0D 43 48 41 52 41 43 54 45 52 20 49 53 20 54 48 |.CHARACTER IS TH|
00007010: 45 20 4C 45 4E 47 54 48 3B 20 CB C5 D2 CD C9 D4 |E LENGTH; ......|
00007020: 20 52 45 41 44 53 20 41 4E 44 20 44 45 43 4F 44 | READS AND DECOD|
00007030: 45 53 20 54 48 45 20 4C 45 4E 47 54 48 20 41 4E |ES THE LENGTH AN|
00007040: 44 20 54 48 45 4E 20 52 45 41 44 53 0D 54 48 41 |D THEN READS.THA|
00007050: 54 20 4D 41 4E 59 20 53 55 42 53 45 51 55 45 4E |T MANY SUBSEQUEN|
00007060: 54 20 43 48 41 52 41 43 54 45 52 53 20 54 4F 20 |T CHARACTERS TO |
00007070: 43 4F 4D 50 4C 45 54 45 20 54 48 45 20 50 41 43 |COMPLETE THE PAC|
00007080: 4B 45 54 2E 20 20 C9 46 20 41 4E 4F 54 48 45 52 |KET. .F ANOTHER|
00007090: 20 D3 CF C8 20 49 53 0D 45 4E 43 4F 55 4E 54 45 | ... IS.ENCOUNTE|
000070A0: 52 45 44 20 42 45 46 4F 52 45 20 54 48 45 20 43 |RED BEFORE THE C|
000070B0: 4F 55 4E 54 20 49 53 20 45 58 48 41 55 53 54 45 |OUNT IS EXHAUSTE|
000070C0: 44 2C 20 54 48 45 20 43 55 52 52 45 4E 54 20 50 |D, THE CURRENT P|
000070D0: 41 43 4B 45 54 20 49 53 20 46 4F 52 47 4F 54 54 |ACKET IS FORGOTT|
000070E0: 45 4E 0D 41 4E 44 20 41 20 4E 45 57 20 4F 4E 45 |EN.AND A NEW ONE|
000070F0: 20 49 53 20 53 54 41 52 54 45 44 2E 20 20 D4 48 | IS STARTED. .H|
00007100: 49 53 20 53 54 52 41 54 41 47 59 20 41 4C 4C 4F |IS STRATAGY ALLO|
00007110: 57 53 20 41 52 42 49 54 52 41 52 59 20 41 4D 4F |WS ARBITRARY AMO|
00007120: 55 4E 54 53 20 4F 46 20 4E 4F 49 53 45 0D 54 4F |UNTS OF NOISE.TO|
00007130: 20 42 45 20 47 45 4E 45 52 41 54 45 44 20 53 50 | BE GENERATED SP|
00007140: 4F 4E 54 41 4E 45 4F 55 53 4C 59 20 42 45 54 57 |ONTANEOUSLY BETW|
00007150: 45 45 4E 20 50 41 43 4B 45 54 53 20 57 49 54 48 |EEN PACKETS WITH|
00007160: 4F 55 54 20 49 4E 54 45 52 46 45 52 49 4E 47 20 |OUT INTERFERING |
00007170: 57 49 54 48 20 54 48 45 0D 50 52 4F 54 4F 43 4F |WITH THE.PROTOCO|
00007180: 4C 2E 0D 0D C5 4E 43 4F 44 49 4E 47 0D 0D D7 48 |L....NCODING...H|
00007190: 45 4E 20 54 52 41 4E 53 4D 49 54 54 49 4E 47 20 |EN TRANSMITTING |
000071A0: 54 45 58 54 55 41 4C 20 44 41 54 41 2C 20 CB C5 |TEXTUAL DATA, ..|
000071B0: D2 CD C9 D4 20 54 45 52 4D 49 4E 41 54 45 53 20 |.... TERMINATES |
000071C0: 4C 4F 47 49 43 41 4C 20 52 45 43 4F 52 44 53 20 |LOGICAL RECORDS |
000071D0: 57 49 54 48 0D 43 41 52 52 49 41 47 45 2D 52 45 |WITH.CARRIAGE-RE|
000071E0: 54 55 52 4E 20 4C 49 4E 45 46 45 45 44 20 43 4F |TURN LINEFEED CO|
000071F0: 4D 42 49 4E 41 54 49 4F 4E 53 20 28 C3 D2 CC C6 |MBINATIONS (....|
00007200: 53 29 2E 20 20 CF 4E 20 52 45 43 4F 52 44 20 4F |S). .N RECORD O|
00007210: 52 49 45 4E 54 45 44 20 53 59 53 54 45 4D 53 2C |RIENTED SYSTEMS,|
00007220: 0D 54 52 41 49 4C 49 4E 47 20 42 4C 41 4E 4B 53 |.TRAILING BLANKS|
00007230: 20 4F 52 20 4C 45 4E 47 54 48 20 46 49 45 4C 44 | OR LENGTH FIELD|
00007240: 53 20 41 52 45 20 52 45 4D 4F 56 45 44 20 41 4E |S ARE REMOVED AN|
00007250: 44 20 41 20 C3 D2 CC C6 20 41 50 50 45 4E 44 45 |D A .... APPENDE|
00007260: 44 20 54 4F 20 4F 55 54 42 4F 55 4E 44 0D 52 45 |D TO OUTBOUND.RE|
00007270: 43 4F 52 44 53 2C 20 57 49 54 48 20 54 48 45 20 |CORDS, WITH THE |
00007280: 49 4E 56 45 52 53 45 20 4F 50 45 52 41 54 49 4F |INVERSE OPERATIO|
00007290: 4E 20 50 45 52 46 4F 52 4D 45 44 20 4F 4E 20 49 |N PERFORMED ON I|
000072A0: 4E 43 4F 4D 49 4E 47 20 52 45 43 4F 52 44 53 2E |NCOMING RECORDS.|
000072B0: 20 20 CF 4E 20 53 54 52 45 41 4D 0D 4F 52 49 45 | .N STREAM.ORIE|
000072C0: 4E 54 45 44 20 53 59 53 54 45 4D 53 2C 20 49 4E |NTED SYSTEMS, IN|
000072D0: 43 4F 4D 49 4E 47 20 C3 D2 CC C6 53 20 4D 41 59 |COMING ....S MAY|
000072E0: 20 42 45 20 54 52 41 4E 53 4C 41 54 45 44 20 54 | BE TRANSLATED T|
000072F0: 4F 20 53 4F 4D 45 20 4F 54 48 45 52 20 54 45 52 |O SOME OTHER TER|
00007300: 4D 49 4E 41 54 4F 52 2E 0D C6 49 4C 45 53 2C 20 |MINATOR...ILES, |
00007310: 4F 46 20 43 4F 55 52 53 45 2C 20 4E 45 45 44 20 |OF COURSE, NEED |
00007320: 4E 4F 54 20 48 41 56 45 20 4C 4F 47 49 43 41 4C |NOT HAVE LOGICAL|
00007330: 20 52 45 43 4F 52 44 53 2C 20 49 4E 20 57 48 49 | RECORDS, IN WHI|
00007340: 43 48 20 43 41 53 45 20 52 45 43 4F 52 44 20 50 |CH CASE RECORD P|
00007350: 52 4F 2D 0D 43 45 53 53 49 4E 47 20 43 41 4E 20 |RO-.CESSING CAN |
00007360: 42 45 20 53 4B 49 50 50 45 44 20 41 4C 54 4F 47 |BE SKIPPED ALTOG|
00007370: 45 54 48 45 52 2C 20 41 4E 44 20 54 48 45 20 46 |ETHER, AND THE F|
00007380: 49 4C 45 20 43 41 4E 20 42 45 20 54 52 45 41 54 |ILE CAN BE TREAT|
00007390: 45 44 20 41 53 20 41 20 4C 4F 4E 47 20 53 54 52 |ED AS A LONG STR|
000073A0: 49 4E 47 0D 4F 46 20 42 59 54 45 53 2E 20 D4 48 |ING.OF BYTES. .H|
000073B0: 49 53 20 49 53 20 4B 4E 4F 57 4E 20 41 53 20 22 |IS IS KNOWN AS "|
000073C0: 49 4D 41 47 45 22 20 54 52 41 4E 53 46 45 52 2C |IMAGE" TRANSFER,|
000073D0: 20 41 4E 44 20 43 41 4E 20 41 4C 53 4F 20 42 45 | AND CAN ALSO BE|
000073E0: 20 55 53 45 44 20 42 45 54 57 45 45 4E 20 4C 49 | USED BETWEEN LI|
000073F0: 4B 45 0D 53 59 53 54 45 4D 53 20 57 48 45 52 45 |KE.SYSTEMS WHERE|
00007400: 20 4E 4F 20 54 52 41 4E 53 46 4F 52 4D 41 54 49 | NO TRANSFORMATI|
00007410: 4F 4E 53 20 41 52 45 20 4E 45 43 45 53 53 41 52 |ONS ARE NECESSAR|
00007420: 59 2E 20 C9 4E 20 4F 52 44 45 52 20 54 4F 20 4D |Y. .N ORDER TO M|
00007430: 41 4B 45 20 45 41 43 48 20 43 48 41 52 41 43 54 |AKE EACH CHARACT|
00007440: 45 52 0D 49 4E 20 54 48 45 20 50 41 43 4B 45 54 |ER.IN THE PACKET|
00007450: 20 50 52 49 4E 54 41 42 4C 45 2C 20 CB C5 D2 CD | PRINTABLE, ....|
00007460: C9 D4 20 22 51 55 4F 54 45 53 22 20 41 4E 59 20 |.. "QUOTES" ANY |
00007470: 55 4E 50 52 49 4E 54 41 42 4C 45 20 43 48 41 52 |UNPRINTABLE CHAR|
00007480: 41 43 54 45 52 20 42 59 20 54 52 41 4E 53 2D 0D |ACTER BY TRANS-.|
00007490: 46 4F 52 4D 49 4E 47 20 49 54 20 54 4F 20 41 20 |FORMING IT TO A |
000074A0: 50 52 49 4E 54 41 42 4C 45 20 4F 4E 45 20 41 4E |PRINTABLE ONE AN|
000074B0: 44 20 50 52 45 43 45 44 45 53 20 49 54 20 57 49 |D PRECEDES IT WI|
000074C0: 54 48 20 41 20 53 50 45 43 49 41 4C 20 50 52 45 |TH A SPECIAL PRE|
000074D0: 46 49 58 20 43 48 41 52 41 43 54 45 52 2E 0D D4 |FIX CHARACTER...|
000074E0: 48 45 20 50 52 45 46 49 58 20 49 53 20 4E 4F 52 |HE PREFIX IS NOR|
000074F0: 4D 41 4C 4C 59 20 22 23 22 3B 20 54 48 45 20 54 |MALLY "#"; THE T|
00007500: 52 41 4E 53 46 4F 52 4D 41 54 49 4F 4E 20 49 53 |RANSFORMATION IS|
00007510: 20 44 4F 4E 45 20 42 59 20 43 4F 4D 50 4C 45 4D | DONE BY COMPLEM|
00007520: 45 4E 54 49 4E 47 20 42 49 54 20 36 0D 28 41 44 |ENTING BIT 6.(AD|
00007530: 44 49 4E 47 20 4F 52 20 53 55 42 54 52 41 43 54 |DING OR SUBTRACT|
00007540: 49 4E 47 20 36 34 29 2E 20 20 D4 48 55 53 20 43 |ING 64). .HUS C|
00007550: 4F 4E 54 52 4F 4C 2D C1 20 42 45 43 4F 4D 45 53 |ONTROL-. BECOMES|
00007560: 20 22 23 C1 22 2C 20 43 4F 4E 54 52 4F 4C 2D DA | "#.", CONTROL-.|
00007570: 20 42 45 43 4F 4D 45 53 0D 22 23 DA 22 2C 20 D5 | BECOMES."#.", .|
00007580: D3 20 28 43 4F 4E 54 52 4F 4C 2D 55 4E 44 45 52 |. (CONTROL-UNDER|
00007590: 53 43 4F 52 45 20 4F 4E 20 4D 4F 53 54 20 54 45 |SCORE ON MOST TE|
000075A0: 52 4D 49 4E 41 4C 53 29 20 42 45 43 4F 4D 45 53 |RMINALS) BECOMES|
000075B0: 20 22 23 5F 22 2E 20 20 D4 48 45 20 50 52 45 46 | "#_". .HE PREF|
000075C0: 49 58 0D 43 48 41 52 41 43 54 45 52 20 49 53 20 |IX.CHARACTER IS |
000075D0: 41 4C 53 4F 20 55 53 45 44 20 54 4F 20 51 55 4F |ALSO USED TO QUO|
000075E0: 54 45 20 49 54 53 45 4C 46 3A 20 22 23 23 22 2E |TE ITSELF: "##".|
000075F0: 20 20 D5 50 4F 4E 20 49 4E 50 55 54 2C 20 54 48 | .PON INPUT, TH|
00007600: 45 20 52 45 56 45 52 53 45 0D 54 52 41 4E 53 46 |E REVERSE.TRANSF|
00007610: 4F 52 4D 41 54 49 4F 4E 20 49 53 20 50 45 52 46 |ORMATION IS PERF|
00007620: 4F 52 4D 45 44 2E 20 20 D0 52 49 4E 54 41 42 4C |ORMED. .RINTABL|
00007630: 45 20 43 48 41 52 41 43 54 45 52 53 20 41 52 45 |E CHARACTERS ARE|
00007640: 20 4E 4F 54 20 54 52 41 4E 53 46 4F 52 4D 45 44 | NOT TRANSFORMED|
00007650: 2E 0D D4 48 45 20 41 53 53 55 4D 50 54 49 4F 4E |...HE ASSUMPTION|
00007660: 20 49 53 20 54 48 41 54 20 4D 4F 53 54 20 46 49 | IS THAT MOST FI|
00007670: 4C 45 53 20 54 4F 20 42 45 20 54 52 41 4E 53 46 |LES TO BE TRANSF|
00007680: 45 52 52 45 44 20 41 52 45 20 50 52 49 4E 54 41 |ERRED ARE PRINTA|
00007690: 42 4C 45 2C 20 41 4E 44 0D 50 52 49 4E 54 41 42 |BLE, AND.PRINTAB|
000076A0: 4C 45 20 46 49 4C 45 53 20 43 4F 4E 54 41 49 4E |LE FILES CONTAIN|
000076B0: 20 52 45 4C 41 54 49 56 45 4C 59 20 46 45 57 20 | RELATIVELY FEW |
000076C0: 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 43 54 45 |CONTROL CHARACTE|
000076D0: 52 53 3B 20 57 48 45 4E 20 54 48 49 53 20 49 53 |RS; WHEN THIS IS|
000076E0: 20 54 52 55 45 2C 0D 54 48 45 20 43 48 41 52 41 | TRUE,.THE CHARA|
000076F0: 43 54 45 52 20 53 54 52 45 41 4D 20 49 53 20 4E |CTER STREAM IS N|
00007700: 4F 54 20 53 49 47 4E 49 46 49 43 41 4E 54 4C 59 |OT SIGNIFICANTLY|
00007710: 20 4C 45 4E 47 54 48 45 4E 45 44 20 42 59 20 51 | LENGTHENED BY Q|
00007720: 55 4F 54 49 4E 47 2E 20 20 C6 4F 52 20 42 49 4E |UOTING. .OR BIN|
00007730: 41 52 59 0D 46 49 4C 45 53 2C 20 54 48 45 20 41 |ARY.FILES, THE A|
00007740: 56 45 52 41 47 45 20 51 55 4F 54 49 4E 47 20 4F |VERAGE QUOTING O|
00007750: 56 45 52 48 45 41 44 20 57 49 4C 4C 20 42 45 20 |VERHEAD WILL BE |
00007760: 32 36 2E 36 25 20 49 46 20 41 4C 4C 20 42 49 54 |26.6% IF ALL BIT|
00007770: 20 50 41 54 54 45 52 4E 53 20 41 52 45 0D 45 51 | PATTERNS ARE.EQ|
00007780: 55 41 4C 4C 59 20 4C 49 4B 45 4C 59 2C 20 53 49 |UALLY LIKELY, SI|
00007790: 4E 43 45 20 54 48 45 20 43 48 41 52 41 43 54 45 |NCE THE CHARACTE|
000077A0: 52 53 20 54 48 41 54 20 4D 55 53 54 20 42 45 20 |RS THAT MUST BE |
000077B0: 51 55 4F 54 45 44 20 28 54 48 45 20 43 4F 4E 54 |QUOTED (THE CONT|
000077C0: 52 4F 4C 20 43 48 41 52 41 43 2D 0D 54 45 52 53 |ROL CHARAC-.TERS|
000077D0: 2C 20 50 4C 55 53 20 C4 C5 CC 2C 20 41 4E 44 20 |, PLUS ..., AND |
000077E0: 22 23 22 20 49 54 53 45 4C 46 29 20 43 4F 4D 50 |"#" ITSELF) COMP|
000077F0: 52 49 53 45 20 32 36 2E 36 25 20 4F 46 20 54 48 |RISE 26.6% OF TH|
00007800: 45 20 C1 D3 C3 C9 C9 20 41 4C 50 48 41 42 45 54 |E ..... ALPHABET|
00007810: 2E 0D 0D CB C5 D2 CD C9 D4 20 41 4C 53 4F 20 50 |......... ALSO P|
00007820: 52 4F 56 49 44 45 53 20 41 20 53 43 48 45 4D 45 |ROVIDES A SCHEME|
00007830: 20 46 4F 52 20 49 4E 44 49 43 41 54 49 4E 47 20 | FOR INDICATING |
00007840: 54 48 45 20 53 54 41 54 55 53 20 4F 46 20 54 48 |THE STATUS OF TH|
00007850: 45 20 38 54 48 20 42 49 54 20 57 48 45 4E 0D 54 |E 8TH BIT WHEN.T|
00007860: 52 41 4E 53 46 45 52 52 49 4E 47 20 42 49 4E 41 |RANSFERRING BINA|
00007870: 52 59 20 46 49 4C 45 53 20 42 45 54 57 45 45 4E |RY FILES BETWEEN|
00007880: 20 53 59 53 54 45 4D 53 20 54 48 41 54 20 4D 55 | SYSTEMS THAT MU|
00007890: 53 54 20 55 53 45 20 54 48 45 20 38 54 48 20 42 |ST USE THE 8TH B|
000078A0: 49 54 20 46 4F 52 20 50 41 52 49 54 59 2E 0D C1 |IT FOR PARITY...|
000078B0: 20 42 59 54 45 20 57 48 4F 53 45 20 38 54 48 20 | BYTE WHOSE 8TH |
000078C0: 42 49 54 20 49 53 20 53 45 54 20 49 53 20 50 52 |BIT IS SET IS PR|
000078D0: 45 43 45 44 45 44 20 42 59 20 41 4E 4F 54 48 45 |ECEDED BY ANOTHE|
000078E0: 52 20 53 50 45 43 49 41 4C 20 51 55 4F 54 49 4E |R SPECIAL QUOTIN|
000078F0: 47 20 43 48 41 52 41 43 54 45 52 2C 0D 22 26 22 |G CHARACTER,."&"|
00007900: 2E 20 20 C9 46 20 54 48 45 20 4C 4F 57 2D 4F 52 |. .F THE LOW-OR|
00007910: 44 45 52 20 37 20 42 49 54 53 20 43 4F 49 4E 43 |DER 7 BITS COINC|
00007920: 49 44 45 20 57 49 54 48 20 41 4E 20 C1 D3 C3 C9 |IDE WITH AN ....|
00007930: C9 20 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 43 |. CONTROL CHARAC|
00007940: 54 45 52 2C 20 54 48 45 4E 0D 43 4F 4E 54 52 4F |TER, THEN.CONTRO|
00007950: 4C 2D 43 48 41 52 41 43 54 45 52 20 51 55 4F 54 |L-CHARACTER QUOT|
00007960: 49 4E 47 20 49 53 20 41 4C 53 4F 20 44 4F 4E 45 |ING IS ALSO DONE|
00007970: 2E 20 20 C6 4F 52 20 49 4E 53 54 41 4E 43 45 2C |. .OR INSTANCE,|
00007980: 20 54 48 45 20 42 59 54 45 20 31 30 30 30 30 30 | THE BYTE 100000|
00007990: 30 31 20 57 4F 55 4C 44 0D 42 45 20 54 52 41 4E |01 WOULD.BE TRAN|
000079A0: 53 4D 49 54 54 45 44 20 41 53 20 22 26 23 C1 22 |SMITTED AS "&#."|
000079B0: 2E 20 20 D4 48 45 20 22 26 22 20 43 48 41 52 41 |. .HE "&" CHARA|
000079C0: 43 54 45 52 20 49 54 53 45 4C 46 20 43 41 4E 20 |CTER ITSELF CAN |
000079D0: 42 45 20 49 4E 43 4C 55 44 45 44 20 41 53 20 44 |BE INCLUDED AS D|
000079E0: 41 54 41 20 42 59 0D 51 55 4F 54 49 4E 47 20 49 |ATA BY.QUOTING I|
000079F0: 54 20 28 23 26 29 2C 20 41 4E 44 20 54 48 45 20 |T (#&), AND THE |
00007A00: 43 4F 4E 54 52 4F 4C 2D 51 55 4F 54 45 20 43 48 |CONTROL-QUOTE CH|
00007A10: 41 52 41 43 54 45 52 20 4D 41 59 20 48 41 56 45 |ARACTER MAY HAVE|
00007A20: 20 49 54 53 20 38 54 48 20 42 49 54 20 53 45 54 | ITS 8TH BIT SET|
00007A30: 0D 28 26 23 23 29 2E 20 38 54 48 2D 42 49 54 20 |.(&##). 8TH-BIT |
00007A40: 51 55 4F 54 49 4E 47 20 49 53 20 4F 4E 4C 59 20 |QUOTING IS ONLY |
00007A50: 44 4F 4E 45 20 57 48 45 4E 20 4E 45 43 45 53 53 |DONE WHEN NECESS|
00007A60: 41 52 59 3B 20 49 46 20 42 4F 54 48 20 53 49 44 |ARY; IF BOTH SID|
00007A70: 45 53 20 43 41 4E 20 43 4F 4E 54 52 4F 4C 0D 54 |ES CAN CONTROL.T|
00007A80: 48 45 20 50 41 52 49 54 59 20 42 49 54 2C 20 54 |HE PARITY BIT, T|
00007A90: 48 45 4E 20 49 54 53 20 56 41 4C 55 45 20 49 53 |HEN ITS VALUE IS|
00007AA0: 20 50 52 45 53 45 52 56 45 44 20 44 55 52 49 4E | PRESERVED DURIN|
00007AB0: 47 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E 2E 20 |G TRANSMISSION. |
00007AC0: 20 C9 46 20 54 48 45 20 38 54 48 0D 42 49 54 20 | .F THE 8TH.BIT |
00007AD0: 49 53 20 53 45 54 20 52 41 4E 44 4F 4D 4C 59 20 |IS SET RANDOMLY |
00007AE0: 4F 4E 20 42 49 4E 41 52 59 20 46 49 4C 45 53 2C |ON BINARY FILES,|
00007AF0: 20 54 48 45 4E 20 38 54 48 2D 42 49 54 20 51 55 | THEN 8TH-BIT QU|
00007B00: 4F 54 49 4E 47 20 57 49 4C 4C 20 41 44 44 20 35 |OTING WILL ADD 5|
00007B10: 30 25 20 43 48 41 52 41 43 2D 0D 54 45 52 20 4F |0% CHARAC-.TER O|
00007B20: 56 45 52 48 45 41 44 2E 20 C6 4F 52 20 53 4F 4D |VERHEAD. .OR SOM|
00007B30: 45 20 4B 49 4E 44 53 20 4F 46 20 42 49 4E 41 52 |E KINDS OF BINAR|
00007B40: 59 20 44 41 54 41 2C 20 49 54 20 43 4F 55 4C 44 |Y DATA, IT COULD|
00007B50: 20 42 45 20 4C 45 53 53 3B 20 46 4F 52 20 49 4E | BE LESS; FOR IN|
00007B60: 53 54 41 4E 43 45 2C 0D 50 4F 53 49 54 49 56 45 |STANCE,.POSITIVE|
00007B70: 20 42 49 4E 41 52 59 20 4E 55 4D 42 45 52 53 20 | BINARY NUMBERS |
00007B80: 49 4E 20 32 27 53 20 43 4F 4D 50 4C 45 4D 45 4E |IN 2'S COMPLEMEN|
00007B90: 54 20 4E 4F 54 41 54 49 4F 4E 20 44 4F 20 4E 4F |T NOTATION DO NO|
00007BA0: 54 20 54 4F 20 48 41 56 45 20 54 48 45 49 52 20 |T TO HAVE THEIR |
00007BB0: 48 49 47 48 2D 0D 4F 52 44 45 52 20 42 49 54 53 |HIGH-.ORDER BITS|
00007BC0: 20 53 45 54 2C 20 49 4E 20 57 48 49 43 48 20 43 | SET, IN WHICH C|
00007BD0: 41 53 45 20 41 54 20 4C 45 41 53 54 20 4F 4E 45 |ASE AT LEAST ONE|
00007BE0: 20 42 59 54 45 20 50 45 52 20 57 4F 52 44 20 57 | BYTE PER WORD W|
00007BF0: 49 4C 4C 20 4E 4F 54 20 42 45 20 51 55 4F 54 45 |ILL NOT BE QUOTE|
00007C00: 44 2E 0D C1 20 54 48 49 52 44 20 4B 49 4E 44 20 |D... THIRD KIND |
00007C10: 4F 46 20 22 51 55 4F 54 49 4E 47 22 20 49 4D 50 |OF "QUOTING" IMP|
00007C20: 4C 45 4D 45 4E 54 53 20 52 55 44 49 4D 45 4E 54 |LEMENTS RUDIMENT|
00007C30: 41 52 59 20 44 41 54 41 20 43 4F 4D 50 52 45 53 |ARY DATA COMPRES|
00007C40: 53 49 4F 4E 2E 20 20 C1 54 20 4C 4F 57 0D 53 50 |SION. .T LOW.SP|
00007C50: 45 45 44 53 2C 20 54 48 45 20 42 4F 54 54 4C 45 |EEDS, THE BOTTLE|
00007C60: 4E 45 43 4B 20 49 4E 20 46 49 4C 45 20 54 52 41 |NECK IN FILE TRA|
00007C70: 4E 53 4D 49 53 53 49 4F 4E 20 49 53 20 4C 49 4B |NSMISSION IS LIK|
00007C80: 45 4C 59 20 54 4F 20 42 45 20 54 48 45 20 4C 49 |ELY TO BE THE LI|
00007C90: 4E 45 20 49 54 53 45 4C 46 2C 0D 53 4F 20 41 4E |NE ITSELF,.SO AN|
00007CA0: 59 20 4D 45 41 53 55 52 45 20 54 48 41 54 20 43 |Y MEASURE THAT C|
00007CB0: 41 4E 20 43 55 54 20 44 4F 57 4E 20 4F 4E 20 55 |AN CUT DOWN ON U|
00007CC0: 53 45 20 4F 46 20 54 48 45 20 4C 49 4E 45 20 57 |SE OF THE LINE W|
00007CD0: 4F 55 4C 44 20 42 45 20 57 45 4C 43 4F 4D 45 2E |OULD BE WELCOME.|
00007CE0: 20 20 D4 48 45 0D 53 50 45 43 49 41 4C 20 50 52 | .HE.SPECIAL PR|
00007CF0: 45 46 49 58 20 43 48 41 52 41 43 54 45 52 20 22 |EFIX CHARACTER "|
00007D00: 3E 22 20 49 4E 44 49 43 41 54 45 53 20 54 48 41 |>" INDICATES THA|
00007D10: 54 20 54 48 45 20 4E 45 58 54 20 43 48 41 52 41 |T THE NEXT CHARA|
00007D20: 43 54 45 52 20 49 53 20 41 20 52 45 50 45 41 54 |CTER IS A REPEAT|
00007D30: 0D 43 4F 55 4E 54 20 28 41 20 53 49 4E 47 4C 45 |.COUNT (A SINGLE|
00007D40: 20 43 48 41 52 41 43 54 45 52 2C 20 45 4E 43 4F | CHARACTER, ENCO|
00007D50: 44 45 44 20 50 52 49 4E 54 41 42 4C 59 29 20 41 |DED PRINTABLY) A|
00007D60: 4E 44 20 54 48 41 54 20 54 48 45 20 43 48 41 52 |ND THAT THE CHAR|
00007D70: 41 43 54 45 52 20 41 46 54 45 52 20 54 48 41 54 |ACTER AFTER THAT|
00007D80: 0D 28 57 48 49 43 48 20 4D 41 59 20 41 4C 53 4F |.(WHICH MAY ALSO|
00007D90: 20 48 41 56 45 20 43 4F 4E 54 52 4F 4C 20 4F 52 | HAVE CONTROL OR|
00007DA0: 20 38 54 48 2D 42 49 54 20 50 52 45 46 49 58 45 | 8TH-BIT PREFIXE|
00007DB0: 53 29 20 49 53 20 52 45 50 45 41 54 45 44 20 53 |S) IS REPEATED S|
00007DC0: 4F 20 4D 41 4E 59 20 54 49 4D 45 53 2E 0D C6 4F |O MANY TIMES...O|
00007DD0: 52 20 49 4E 53 54 41 4E 43 45 20 22 3E 3D C1 22 |R INSTANCE ">=."|
00007DE0: 20 49 4E 44 49 43 41 54 45 53 20 41 20 53 45 52 | INDICATES A SER|
00007DF0: 49 45 53 20 4F 46 20 39 33 20 4C 45 54 54 45 52 |IES OF 93 LETTER|
00007E00: 20 C1 27 53 3B 20 22 3E C8 26 23 C2 22 20 49 4E | .'S; ">.&#." IN|
00007E10: 44 49 43 41 54 45 53 20 41 0D 53 45 52 49 45 53 |DICATES A.SERIES|
00007E20: 20 4F 46 20 34 30 20 43 4F 4E 54 52 4F 4C 2D C2 | OF 40 CONTROL-.|
00007E30: 27 53 20 57 49 54 48 20 54 48 45 20 50 41 52 49 |'S WITH THE PARI|
00007E40: 54 59 20 42 49 54 20 53 45 54 2E 20 20 D4 48 45 |TY BIT SET. .HE|
00007E50: 20 52 45 50 45 41 54 20 43 4F 55 4E 54 20 50 52 | REPEAT COUNT PR|
00007E60: 45 46 49 58 0D 49 54 53 45 4C 46 20 43 41 4E 20 |EFIX.ITSELF CAN |
00007E70: 42 45 20 49 4E 43 4C 55 44 45 44 20 41 53 20 54 |BE INCLUDED AS T|
00007E80: 45 58 54 20 42 59 20 51 55 4F 54 49 4E 47 20 49 |EXT BY QUOTING I|
00007E90: 54 20 57 49 54 48 20 22 23 22 2E 0D D4 4F 20 4B |T WITH "#"...O K|
00007EA0: 45 45 50 20 54 48 45 20 50 52 4F 54 4F 43 4F 4C |EEP THE PROTOCOL|
00007EB0: 20 53 49 4D 50 4C 45 2C 20 4E 4F 20 4F 54 48 45 | SIMPLE, NO OTHE|
00007EC0: 52 20 54 52 41 4E 53 46 4F 52 4D 41 54 49 4F 4E |R TRANSFORMATION|
00007ED0: 53 20 41 52 45 20 44 4F 4E 45 2E 20 20 C1 54 20 |S ARE DONE. .T |
00007EE0: 54 48 49 53 20 50 4F 49 4E 54 2C 0D 48 4F 57 45 |THIS POINT,.HOWE|
00007EF0: 56 45 52 2C 20 49 54 20 4D 49 47 48 54 20 42 45 |VER, IT MIGHT BE|
00007F00: 20 57 4F 52 54 48 20 4D 45 4E 54 49 4F 4E 49 4E | WORTH MENTIONIN|
00007F10: 47 20 53 4F 4D 45 20 54 48 49 4E 47 53 20 57 45 |G SOME THINGS WE|
00007F20: 20 44 49 44 20 4E 4F 54 20 44 4F 20 54 4F 20 54 | DID NOT DO TO T|
00007F30: 48 45 20 44 41 54 41 3A 0D 20 20 20 20 20 20 20 |HE DATA:. |
00007F40: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00007F50: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00007F60: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00007F70: 20 20 3D 3D 3D 0D 0D C6 41 4E 43 59 20 C4 41 54 | ===...ANCY .AT|
00007F80: 41 20 43 4F 4D 50 52 45 53 53 49 4F 4E 2E 20 20 |A COMPRESSION. |
00007F90: C9 46 20 54 48 45 20 44 41 54 41 20 49 53 20 4B |.F THE DATA IS K|
00007FA0: 4E 4F 57 4E 20 54 4F 20 42 45 20 28 4F 52 20 52 |NOWN TO BE (OR R|
00007FB0: 45 53 45 4D 42 4C 45 29 20 C5 4E 47 4C 49 53 48 |ESEMBLE) .NGLISH|
00007FC0: 20 54 45 58 54 2C 0D 41 20 C8 55 46 46 4D 41 4E | TEXT,.A .UFFMAN|
00007FD0: 20 45 4E 43 4F 44 49 4E 47 20 42 41 53 45 44 20 | ENCODING BASED |
00007FE0: 4F 4E 20 54 48 45 20 46 52 45 51 55 45 4E 43 59 |ON THE FREQUENCY|
00007FF0: 20 4F 46 20 43 48 41 52 41 43 54 45 52 53 20 49 | OF CHARACTERS I|
00008000: 4E 20 C5 4E 47 4C 49 53 48 20 54 45 58 54 20 43 |N .NGLISH TEXT C|
00008010: 4F 55 4C 44 0D 42 45 20 55 53 45 44 2E 20 20 C1 |OULD.BE USED. .|
00008020: 20 C8 55 46 46 4D 41 4E 20 43 4F 44 45 20 52 45 | .UFFMAN CODE RE|
00008030: 53 45 4D 42 4C 45 53 20 CD 4F 52 53 45 20 43 4F |SEMBLES .ORSE CO|
00008040: 44 45 2C 20 57 48 49 43 48 20 48 41 53 20 56 41 |DE, WHICH HAS VA|
00008050: 52 49 41 42 4C 45 20 4C 45 4E 47 54 48 0D 43 48 |RIABLE LENGTH.CH|
00008060: 41 52 41 43 54 45 52 53 20 57 48 4F 53 45 20 42 |ARACTERS WHOSE B|
00008070: 4F 55 4E 44 41 52 49 45 53 20 43 41 4E 20 41 4C |OUNDARIES CAN AL|
00008080: 57 41 59 53 20 42 45 20 44 49 53 54 49 4E 47 55 |WAYS BE DISTINGU|
00008090: 49 53 48 45 44 2E 20 20 D4 48 45 20 4D 4F 52 45 |ISHED. .HE MORE|
000080A0: 20 46 52 45 51 55 45 4E 54 20 54 48 45 0D 43 48 | FREQUENT THE.CH|
000080B0: 41 52 41 43 54 45 52 2C 20 54 48 45 20 53 48 4F |ARACTER, THE SHO|
000080C0: 52 54 45 52 20 54 48 45 20 42 49 54 20 53 54 52 |RTER THE BIT STR|
000080D0: 49 4E 47 20 54 4F 20 52 45 50 52 45 53 45 4E 54 |ING TO REPRESENT|
000080E0: 20 49 54 2E 20 20 CF 46 20 43 4F 55 52 53 45 2C | IT. .F COURSE,|
000080F0: 20 54 48 49 53 20 53 43 48 45 4D 45 0D 43 41 4E | THIS SCHEME.CAN|
00008100: 20 42 41 43 4B 46 49 52 45 20 49 46 20 54 48 45 | BACKFIRE IF THE|
00008110: 20 43 48 41 52 41 43 54 45 52 20 44 49 53 54 52 | CHARACTER DISTR|
00008120: 49 42 55 54 49 4F 4E 20 4F 46 20 54 48 45 20 44 |IBUTION OF THE D|
00008130: 41 54 41 20 49 53 20 56 45 52 59 20 44 49 46 46 |ATA IS VERY DIFF|
00008140: 45 52 45 4E 54 20 46 52 4F 4D 0D 54 48 45 20 4F |ERENT FROM.THE O|
00008150: 4E 45 20 41 53 53 55 4D 45 44 2E 20 C9 4E 20 41 |NE ASSUMED. .N A|
00008160: 4E 59 20 43 41 53 45 2C 20 56 41 52 49 41 42 4C |NY CASE, VARIABL|
00008170: 45 20 4C 45 4E 47 54 48 20 43 48 41 52 41 43 54 |E LENGTH CHARACT|
00008180: 45 52 53 20 41 4E 44 20 C1 D3 C3 C9 C9 20 54 52 |ERS AND ..... TR|
00008190: 41 4E 53 4D 49 53 53 49 4F 4E 0D 44 4F 4E 27 54 |ANSMISSION.DON'T|
000081A0: 20 4D 49 58 20 57 45 4C 4C 2E 0D 0D C5 52 52 4F | MIX WELL....RRO|
000081B0: 52 20 C3 4F 52 52 45 43 54 49 4E 47 20 C3 4F 44 |R .ORRECTING .OD|
000081C0: 45 53 2E 20 D4 45 43 48 4E 49 51 55 45 53 2C 20 |ES. .ECHNIQUES, |
000081D0: 53 55 43 48 20 41 53 20 C8 41 4D 4D 49 4E 47 20 |SUCH AS .AMMING |
000081E0: 43 4F 44 45 53 2C 20 45 58 49 53 54 20 46 4F 52 |CODES, EXIST FOR|
000081F0: 20 44 45 54 45 43 54 49 4E 47 0D 41 4E 44 20 43 | DETECTING.AND C|
00008200: 4F 52 52 45 43 54 49 4E 47 20 45 52 52 4F 52 53 |ORRECTING ERRORS|
00008210: 20 4F 4E 20 41 20 50 45 52 2D 43 48 41 52 41 43 | ON A PER-CHARAC|
00008220: 54 45 52 20 42 41 53 49 53 2E 20 D4 48 45 53 45 |TER BASIS. .HESE|
00008230: 20 41 52 45 20 45 58 50 45 4E 53 49 56 45 20 49 | ARE EXPENSIVE I|
00008240: 4E 0D 52 45 53 4F 55 52 43 45 53 20 41 4E 44 20 |N.RESOURCES AND |
00008250: 43 4F 4D 50 4C 45 58 20 54 4F 20 50 52 4F 47 52 |COMPLEX TO PROGR|
00008260: 41 4D 2E 20 CB C5 D2 CD C9 D4 20 55 53 45 53 20 |AM. ...... USES |
00008270: 50 45 52 2D 50 41 43 4B 45 54 20 42 4C 4F 43 4B |PER-PACKET BLOCK|
00008280: 20 43 48 45 43 4B 0D 54 45 43 48 4E 49 51 55 45 | CHECK.TECHNIQUE|
00008290: 53 2C 20 57 48 49 43 48 20 41 52 45 20 45 58 50 |S, WHICH ARE EXP|
000082A0: 4C 41 49 4E 45 44 20 42 45 4C 4F 57 2E 0D 0D CE |LAINED BELOW....|
000082B0: 49 42 42 4C 45 20 C5 4E 43 4F 44 49 4E 47 2E 20 |IBBLE .NCODING. |
000082C0: 20 D4 4F 20 43 49 52 43 55 4D 56 45 4E 54 20 50 | .O CIRCUMVENT P|
000082D0: 52 4F 42 4C 45 4D 53 20 57 49 54 48 20 43 4F 4E |ROBLEMS WITH CON|
000082E0: 54 52 4F 4C 20 41 4E 44 20 38 2D 42 49 54 20 43 |TROL AND 8-BIT C|
000082F0: 48 41 52 41 43 54 45 52 53 2C 20 49 54 0D 57 4F |HARACTERS, IT.WO|
00008300: 55 4C 44 20 48 41 56 45 20 42 45 45 4E 20 50 4F |ULD HAVE BEEN PO|
00008310: 53 53 49 42 4C 45 20 54 4F 20 44 49 56 49 44 45 |SSIBLE TO DIVIDE|
00008320: 20 45 56 45 52 59 20 43 48 41 52 41 43 54 45 52 | EVERY CHARACTER|
00008330: 20 49 4E 54 4F 20 54 57 4F 20 34 2D 42 49 54 20 | INTO TWO 4-BIT |
00008340: 22 4E 49 42 42 4C 45 53 22 2C 0D 53 45 4E 44 49 |"NIBBLES",.SENDI|
00008350: 4E 47 20 45 41 43 48 20 4E 49 42 42 4C 45 20 41 |NG EACH NIBBLE A|
00008360: 53 20 41 20 50 52 49 4E 54 41 42 4C 45 20 43 48 |S A PRINTABLE CH|
00008370: 41 52 41 43 54 45 52 20 28 45 2E 47 2E 20 41 20 |ARACTER (E.G. A |
00008380: 48 45 58 41 44 45 43 49 4D 41 4C 20 44 49 47 49 |HEXADECIMAL DIGI|
00008390: 54 29 2E 20 D4 48 45 0D 43 48 41 52 41 43 54 45 |T). .HE.CHARACTE|
000083A0: 52 20 4F 56 45 52 48 45 41 44 20 43 41 55 53 45 |R OVERHEAD CAUSE|
000083B0: 44 20 42 59 20 54 48 49 53 20 53 43 48 45 4D 45 |D BY THIS SCHEME|
000083C0: 20 57 4F 55 4C 44 20 57 4F 55 4C 44 20 41 4C 57 | WOULD WOULD ALW|
000083D0: 41 59 53 20 42 45 20 31 30 30 25 2E 20 C2 55 54 |AYS BE 100%. .UT|
000083E0: 20 49 54 0D 57 4F 55 4C 44 20 42 45 20 41 4E 20 | IT.WOULD BE AN |
000083F0: 45 41 53 59 20 57 41 59 20 54 4F 20 54 52 41 4E |EASY WAY TO TRAN|
00008400: 53 46 45 52 20 42 49 4E 41 52 59 20 46 49 4C 45 |SFER BINARY FILE|
00008410: 53 2E 0D 0D 0D C5 52 52 4F 52 20 C4 45 54 45 43 |S.....RROR .ETEC|
00008420: 54 49 4F 4E 0D 0D C3 48 41 52 41 43 54 45 52 20 |TION...HARACTER |
00008430: 50 41 52 49 54 59 20 41 4E 44 20 C8 41 4D 4D 49 |PARITY AND .AMMI|
00008440: 4E 47 20 43 4F 44 45 53 20 41 52 45 20 46 4F 52 |NG CODES ARE FOR|
00008450: 4D 53 20 4F 46 20 22 56 45 52 54 49 43 41 4C 20 |MS OF "VERTICAL |
00008460: 52 45 44 55 4E 44 41 4E 43 59 20 43 48 45 43 4B |REDUNDANCY CHECK|
00008470: 53 22 0D 28 D6 D2 C3 53 29 2C 20 46 4F 52 4D 45 |S".(...S), FORME|
00008480: 44 20 42 59 20 43 4F 4D 42 49 4E 49 4E 47 20 41 |D BY COMBINING A|
00008490: 4C 4C 20 54 48 45 20 42 49 54 53 20 4F 46 20 41 |LL THE BITS OF A|
000084A0: 20 43 48 41 52 41 43 54 45 52 20 49 4E 20 4F 4E | CHARACTER IN ON|
000084B0: 45 20 57 41 59 20 4F 52 20 41 4E 4F 54 48 45 52 |E WAY OR ANOTHER|
000084C0: 2E 0D D4 48 45 20 4F 54 48 45 52 20 4B 49 4E 44 |...HE OTHER KIND|
000084D0: 20 4F 46 20 43 48 45 43 4B 20 54 48 41 54 20 43 | OF CHECK THAT C|
000084E0: 41 4E 20 42 45 20 55 53 45 44 20 49 53 20 54 48 |AN BE USED IS TH|
000084F0: 45 20 22 4C 4F 4E 47 49 54 55 44 49 4E 41 4C 20 |E "LONGITUDINAL |
00008500: 52 45 44 55 4E 44 41 4E 43 59 20 43 48 45 43 4B |REDUNDANCY CHECK|
00008510: 22 0D 28 CC D2 C3 29 2C 20 57 48 49 43 48 20 50 |".(...), WHICH P|
00008520: 52 4F 44 55 43 45 53 20 41 20 22 42 4C 4F 43 4B |RODUCES A "BLOCK|
00008530: 20 43 48 45 43 4B 20 43 48 41 52 41 43 54 45 52 | CHECK CHARACTER|
00008540: 22 20 46 4F 52 4D 45 44 20 42 59 20 53 4F 4D 45 |" FORMED BY SOME|
00008550: 20 43 4F 4D 42 49 4E 41 54 49 4F 4E 20 4F 46 0D | COMBINATION OF.|
00008560: 45 41 43 48 20 43 48 41 52 41 43 54 45 52 20 57 |EACH CHARACTER W|
00008570: 49 54 48 49 4E 20 41 20 53 45 51 55 45 4E 43 45 |ITHIN A SEQUENCE|
00008580: 2E 20 20 D4 48 45 20 53 45 4E 44 49 4E 47 20 53 |. .HE SENDING S|
00008590: 49 44 45 20 43 4F 4D 50 55 54 45 53 20 54 48 45 |IDE COMPUTES THE|
000085A0: 20 CC D2 C3 20 41 4E 44 20 53 45 4E 44 53 0D 49 | ... AND SENDS.I|
000085B0: 54 20 57 49 54 48 20 54 48 45 20 50 41 43 4B 45 |T WITH THE PACKE|
000085C0: 54 3B 20 54 48 45 20 52 45 43 45 49 56 49 4E 47 |T; THE RECEIVING|
000085D0: 20 53 49 44 45 20 52 45 43 4F 4D 50 55 54 45 53 | SIDE RECOMPUTES|
000085E0: 20 49 54 20 46 4F 52 20 43 4F 4D 50 41 52 49 53 | IT FOR COMPARIS|
000085F0: 4F 4E 2E 20 D4 48 45 52 45 20 41 52 45 0D 56 41 |ON. .HERE ARE.VA|
00008600: 52 49 4F 55 53 20 46 4F 52 4D 53 20 4F 46 20 CC |RIOUS FORMS OF .|
00008610: D2 C3 53 2E 20 20 CF 4E 45 20 46 4F 52 4D 20 50 |..S. .NE FORM P|
00008620: 52 4F 44 55 43 45 53 20 41 20 22 43 4F 4C 55 4D |RODUCES A "COLUM|
00008630: 4E 20 50 41 52 49 54 59 22 20 43 48 41 52 41 43 |N PARITY" CHARAC|
00008640: 54 45 52 2C 20 4F 52 0D 22 4C 4F 47 49 43 41 4C |TER, OR."LOGICAL|
00008650: 20 53 55 4D 22 2C 20 57 48 4F 53 45 20 42 49 54 | SUM", WHOSE BIT|
00008660: 53 20 41 52 45 20 54 48 45 20 45 58 43 4C 55 53 |S ARE THE EXCLUS|
00008670: 49 56 45 2D CF D2 53 20 4F 46 20 54 48 45 20 43 |IVE-..S OF THE C|
00008680: 4F 52 52 45 53 50 4F 4E 44 49 4E 47 20 42 49 54 |ORRESPONDING BIT|
00008690: 53 20 4F 46 0D 54 48 45 20 44 41 54 41 20 43 48 |S OF.THE DATA CH|
000086A0: 41 52 41 43 54 45 52 53 2E 20 20 C1 4E 4F 54 48 |ARACTERS. .NOTH|
000086B0: 45 52 20 49 53 20 54 48 45 20 22 43 48 45 43 4B |ER IS THE "CHECK|
000086C0: 53 55 4D 22 20 57 48 49 43 48 20 49 53 20 54 48 |SUM" WHICH IS TH|
000086D0: 45 20 41 52 49 54 48 4D 45 54 49 43 20 53 55 4D |E ARITHMETIC SUM|
000086E0: 20 4F 46 0D 41 4C 4C 20 54 48 45 20 43 48 41 52 | OF.ALL THE CHAR|
000086F0: 41 43 54 45 52 53 20 49 4E 20 54 48 45 20 53 45 |ACTERS IN THE SE|
00008700: 51 55 45 4E 43 45 2C 20 49 4E 54 45 52 50 52 45 |QUENCE, INTERPRE|
00008710: 54 45 44 20 4E 55 4D 45 52 49 43 41 4C 4C 59 2E |TED NUMERICALLY.|
00008720: 20 20 C1 4E 4F 54 48 45 52 20 49 53 20 54 48 45 | .NOTHER IS THE|
00008730: 0D 22 C3 59 43 4C 49 43 20 D2 45 44 55 4E 44 41 |.".YCLIC .EDUNDA|
00008740: 4E 43 59 20 C3 48 45 43 4B 22 20 28 C3 D2 C3 29 |NCY .HECK" (...)|
00008750: 2C 20 57 48 49 43 48 20 50 41 53 53 45 53 20 54 |, WHICH PASSES T|
00008760: 48 45 20 43 48 41 52 41 43 54 45 52 53 20 54 48 |HE CHARACTERS TH|
00008770: 52 4F 55 47 48 20 57 48 41 54 0D 41 4D 4F 55 4E |ROUGH WHAT.AMOUN|
00008780: 54 53 20 54 4F 20 41 20 53 48 49 46 54 20 52 45 |TS TO A SHIFT RE|
00008790: 47 49 53 54 45 52 20 57 49 54 48 20 49 4D 42 45 |GISTER WITH IMBE|
000087A0: 44 44 45 44 20 46 45 45 44 42 41 43 4B 20 4C 4F |DDED FEEDBACK LO|
000087B0: 4F 50 53 2C 20 50 52 4F 44 55 43 49 4E 47 20 41 |OPS, PRODUCING A|
000087C0: 20 42 4C 4F 43 4B 0D 43 48 45 43 4B 20 49 4E 20 | BLOCK.CHECK IN |
000087D0: 57 48 49 43 48 20 45 41 43 48 20 42 49 54 20 49 |WHICH EACH BIT I|
000087E0: 53 20 45 46 46 45 43 54 45 44 20 49 4E 20 4D 41 |S EFFECTED IN MA|
000087F0: 4E 59 20 57 41 59 53 20 42 59 20 54 48 45 20 50 |NY WAYS BY THE P|
00008800: 52 45 43 45 44 49 4E 47 20 43 48 41 52 41 43 54 |RECEDING CHARACT|
00008810: 45 52 53 2E 0D C1 4C 4C 20 4F 46 20 54 48 45 53 |ERS...LL OF THES|
00008820: 45 20 54 45 43 48 4E 49 51 55 45 53 20 57 49 4C |E TECHNIQUES WIL|
00008830: 4C 20 43 41 54 43 48 20 53 49 4E 47 4C 45 2D 42 |L CATCH SINGLE-B|
00008840: 49 54 20 45 52 52 4F 52 53 2E 20 20 D4 48 45 59 |IT ERRORS. .HEY|
00008850: 20 56 41 52 59 20 49 4E 20 54 48 45 49 52 0D 41 | VARY IN THEIR.A|
00008860: 42 49 4C 49 54 59 20 54 4F 20 44 45 54 45 43 54 |BILITY TO DETECT|
00008870: 20 4F 54 48 45 52 20 4B 49 4E 44 53 20 4F 46 20 | OTHER KINDS OF |
00008880: 45 52 52 4F 52 53 2E 20 20 C6 4F 52 20 49 4E 53 |ERRORS. .OR INS|
00008890: 54 41 4E 43 45 2C 20 41 20 44 4F 55 42 4C 45 2D |TANCE, A DOUBLE-|
000088A0: 42 49 54 20 43 4F 4C 55 4D 4E 0D 45 52 52 4F 52 |BIT COLUMN.ERROR|
000088B0: 20 57 49 4C 4C 20 41 4C 57 41 59 53 20 47 4F 20 | WILL ALWAYS GO |
000088C0: 55 4E 44 45 54 45 43 54 45 44 20 57 49 54 48 20 |UNDETECTED WITH |
000088D0: 43 4F 4C 55 4D 4E 20 50 41 52 49 54 59 2C 20 53 |COLUMN PARITY, S|
000088E0: 49 4E 43 45 20 54 48 45 20 52 45 53 55 4C 54 20 |INCE THE RESULT |
000088F0: 4F 46 20 D8 CF D2 49 4E 47 0D 41 4E 59 20 54 57 |OF ...ING.ANY TW|
00008900: 4F 20 42 49 54 53 20 54 4F 47 45 54 48 45 52 20 |O BITS TOGETHER |
00008910: 49 53 20 54 48 45 20 53 41 4D 45 20 41 53 20 D8 |IS THE SAME AS .|
00008920: CF D2 49 4E 47 20 54 48 45 49 52 20 43 4F 4D 50 |..ING THEIR COMP|
00008930: 4C 45 4D 45 4E 54 53 2C 20 57 48 45 52 45 41 53 |LEMENTS, WHEREAS|
00008940: 20 48 41 4C 46 20 54 48 45 0D 50 4F 53 53 49 42 | HALF THE.POSSIB|
00008950: 4C 45 20 44 4F 55 42 4C 45 20 42 49 54 20 45 52 |LE DOUBLE BIT ER|
00008960: 52 4F 52 53 20 43 41 4E 20 42 45 20 43 41 55 47 |RORS CAN BE CAUG|
00008970: 48 54 20 42 59 20 41 44 44 49 54 49 4F 4E 20 42 |HT BY ADDITION B|
00008980: 45 43 41 55 53 45 20 4F 46 20 54 48 45 20 43 41 |ECAUSE OF THE CA|
00008990: 52 52 59 20 49 4E 54 4F 0D 54 48 45 20 4E 45 58 |RRY INTO.THE NEX|
000089A0: 54 20 42 49 54 20 50 4F 53 49 54 49 4F 4E 2E 20 |T BIT POSITION. |
000089B0: 20 C3 D2 C3 20 44 4F 45 53 20 45 56 45 4E 20 42 | ... DOES EVEN B|
000089C0: 45 54 54 45 52 20 42 59 20 52 49 50 50 4C 49 4E |ETTER BY RIPPLIN|
000089D0: 47 20 54 48 45 20 45 46 46 45 43 54 20 4F 46 20 |G THE EFFECT OF |
000089E0: 41 20 44 41 54 41 0D 42 49 54 20 4D 55 4C 54 49 |A DATA.BIT MULTI|
000089F0: 50 4C 59 20 54 48 52 4F 55 47 48 20 54 48 45 20 |PLY THROUGH THE |
00008A00: 42 4C 4F 43 4B 20 43 48 45 43 4B 20 43 48 41 52 |BLOCK CHECK CHAR|
00008A10: 41 43 54 45 52 2C 20 42 55 54 20 54 48 45 20 4D |ACTER, BUT THE M|
00008A20: 45 54 48 4F 44 20 49 53 20 43 4F 4D 50 4C 45 58 |ETHOD IS COMPLEX|
00008A30: 2C 20 41 4E 44 0D 41 20 53 4F 46 54 57 41 52 45 |, AND.A SOFTWARE|
00008A40: 20 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E 20 | IMPLEMENTATION |
00008A50: 4F 46 20 C3 D2 C3 20 43 41 4E 20 42 45 20 49 4E |OF ... CAN BE IN|
00008A60: 53 43 52 55 54 41 42 4C 45 2E 20 D3 54 41 4E 44 |SCRUTABLE. .TAND|
00008A70: 41 52 44 2C 20 42 41 53 45 2D 4C 45 56 45 4C 0D |ARD, BASE-LEVEL.|
00008A80: CB C5 D2 CD C9 D4 20 45 4D 50 4C 4F 59 53 20 41 |...... EMPLOYS A|
00008A90: 20 53 49 4E 47 4C 45 2D 43 48 41 52 41 43 54 45 | SINGLE-CHARACTE|
00008AA0: 52 20 41 52 49 54 48 4D 45 54 49 43 20 43 48 45 |R ARITHMETIC CHE|
00008AB0: 43 4B 53 55 4D 2C 20 57 48 49 43 48 20 49 53 20 |CKSUM, WHICH IS |
00008AC0: 53 49 4D 50 4C 45 20 54 4F 0D 50 52 4F 47 52 41 |SIMPLE TO.PROGRA|
00008AD0: 4D 2C 20 49 53 20 4C 4F 57 20 49 4E 20 4F 56 45 |M, IS LOW IN OVE|
00008AE0: 52 48 45 41 44 2C 20 41 4E 44 20 48 41 53 20 50 |RHEAD, AND HAS P|
00008AF0: 52 4F 56 45 4E 20 51 55 49 54 45 20 41 44 45 51 |ROVEN QUITE ADEQ|
00008B00: 55 41 54 45 20 49 4E 20 50 52 41 43 54 49 43 45 |UATE IN PRACTICE|
00008B10: 2E 20 D4 48 45 0D 53 55 4D 20 49 53 20 46 4F 52 |. .HE.SUM IS FOR|
00008B20: 4D 45 44 20 42 59 20 41 44 44 49 4E 47 20 54 4F |MED BY ADDING TO|
00008B30: 47 45 54 48 45 52 20 54 48 45 20 C1 D3 C3 C9 C9 |GETHER THE .....|
00008B40: 20 56 41 4C 55 45 53 20 4F 46 20 45 41 43 48 20 | VALUES OF EACH |
00008B50: 43 48 41 52 41 43 54 45 52 20 49 4E 20 54 48 45 |CHARACTER IN THE|
00008B60: 0D 50 41 43 4B 45 54 20 45 58 43 45 50 54 20 54 |.PACKET EXCEPT T|
00008B70: 48 45 20 D3 CF C8 20 41 4E 44 20 54 48 45 20 43 |HE ... AND THE C|
00008B80: 48 45 43 4B 53 55 4D 20 49 54 53 45 4C 46 2C 20 |HECKSUM ITSELF, |
00008B90: 41 4E 44 20 49 4E 43 4C 55 44 49 4E 47 20 41 4E |AND INCLUDING AN|
00008BA0: 59 20 51 55 4F 54 49 4E 47 0D 43 48 41 52 41 43 |Y QUOTING.CHARAC|
00008BB0: 54 45 52 53 2E 20 20 C5 56 45 4E 20 4E 4F 4E 2D |TERS. .VEN NON-|
00008BC0: C1 D3 C3 C9 C9 20 48 4F 53 54 53 20 4D 55 53 54 |..... HOSTS MUST|
00008BD0: 20 44 4F 20 54 48 49 53 20 43 41 4C 43 55 4C 41 | DO THIS CALCULA|
00008BE0: 54 49 4F 4E 20 49 4E 20 C1 D3 C3 C9 C9 2E 20 D4 |TION IN ...... .|
00008BF0: 48 45 0D 52 45 53 55 4C 54 20 43 41 4E 20 41 50 |HE.RESULT CAN AP|
00008C00: 50 52 4F 41 43 48 20 31 32 2C 30 30 30 20 49 4E |PROACH 12,000 IN|
00008C10: 20 54 48 45 20 57 4F 52 53 54 20 43 41 53 45 2E | THE WORST CASE.|
00008C20: 20 20 D4 48 45 20 42 49 4E 41 52 59 20 52 45 50 | .HE BINARY REP|
00008C30: 52 45 53 45 4E 54 41 54 49 4F 4E 20 4F 46 0D 54 |RESENTATION OF.T|
00008C40: 48 49 53 20 4E 55 4D 42 45 52 20 49 53 20 31 30 |HIS NUMBER IS 10|
00008C50: 31 31 31 30 31 31 31 30 30 30 30 30 2C 20 57 48 |111011100000, WH|
00008C60: 49 43 48 20 49 53 20 31 34 20 42 49 54 53 20 4C |ICH IS 14 BITS L|
00008C70: 4F 4E 47 2E 20 20 D4 48 49 53 20 49 53 20 4D 55 |ONG. .HIS IS MU|
00008C80: 43 48 20 4D 4F 52 45 20 54 48 41 4E 0D 4F 4E 45 |CH MORE THAN.ONE|
00008C90: 20 43 48 41 52 41 43 54 45 52 27 53 20 57 4F 52 | CHARACTER'S WOR|
00008CA0: 54 48 20 4F 46 20 42 49 54 53 2C 20 42 55 54 20 |TH OF BITS, BUT |
00008CB0: 57 45 20 43 41 4E 20 4D 41 4B 45 20 54 48 45 20 |WE CAN MAKE THE |
00008CC0: 4F 42 53 45 52 56 41 54 49 4F 4E 20 54 48 41 54 |OBSERVATION THAT|
00008CD0: 20 45 56 45 52 59 0D 43 48 41 52 41 43 54 45 52 | EVERY.CHARACTER|
00008CE0: 20 49 4E 43 4C 55 44 45 44 20 49 4E 20 54 48 45 | INCLUDED IN THE|
00008CF0: 20 53 55 4D 20 48 41 53 20 43 4F 4E 54 52 49 42 | SUM HAS CONTRIB|
00008D00: 55 54 45 44 20 54 4F 20 54 48 45 20 4C 4F 57 20 |UTED TO THE LOW |
00008D10: 4F 52 44 45 52 20 37 20 42 49 54 53 2C 20 53 4F |ORDER 7 BITS, SO|
00008D20: 20 57 45 0D 43 41 4E 20 44 49 53 43 41 52 44 20 | WE.CAN DISCARD |
00008D30: 53 4F 4D 45 20 48 49 47 48 20 4F 52 44 45 52 20 |SOME HIGH ORDER |
00008D40: 42 49 54 53 20 41 4E 44 20 53 54 49 4C 4C 20 48 |BITS AND STILL H|
00008D50: 41 56 45 20 41 20 56 49 41 42 4C 45 20 56 41 4C |AVE A VIABLE VAL|
00008D60: 49 44 49 54 59 20 43 48 45 43 4B 2E 0D 0D D4 48 |IDITY CHECK....H|
00008D70: 45 20 CB C5 D2 CD C9 D4 20 50 52 4F 54 4F 43 4F |E ...... PROTOCO|
00008D80: 4C 20 41 4C 53 4F 20 41 4C 4C 4F 57 53 20 4F 54 |L ALSO ALLOWS OT|
00008D90: 48 45 52 20 42 4C 4F 43 4B 20 43 48 45 43 4B 20 |HER BLOCK CHECK |
00008DA0: 4F 50 54 49 4F 4E 53 2C 20 49 4E 43 4C 55 44 49 |OPTIONS, INCLUDI|
00008DB0: 4E 47 20 41 20 54 57 4F 2D 0D 43 48 41 52 41 43 |NG A TWO-.CHARAC|
00008DC0: 54 45 52 20 43 48 45 43 4B 53 55 4D 20 41 4E 44 |TER CHECKSUM AND|
00008DD0: 20 41 20 54 48 52 45 45 2D 43 48 41 52 41 43 54 | A THREE-CHARACT|
00008DE0: 45 52 20 31 36 2D 42 49 54 20 C3 D2 C3 2E 20 20 |ER 16-BIT .... |
00008DF0: D4 48 45 20 54 57 4F 2D 43 48 41 52 41 43 54 45 |.HE TWO-CHARACTE|
00008E00: 52 0D 43 48 45 43 4B 53 55 4D 20 49 53 20 53 49 |R.CHECKSUM IS SI|
00008E10: 4D 50 4C 59 20 54 48 45 20 4C 4F 57 20 4F 52 44 |MPLY THE LOW ORD|
00008E20: 45 52 20 31 32 20 42 49 54 53 20 4F 46 20 54 48 |ER 12 BITS OF TH|
00008E30: 45 20 41 52 49 54 48 4D 45 54 49 43 20 53 55 4D |E ARITHMETIC SUM|
00008E40: 2C 20 42 52 4F 4B 45 4E 20 49 4E 54 4F 0D 54 57 |, BROKEN INTO.TW|
00008E50: 4F 20 50 52 49 4E 54 41 42 4C 45 20 43 48 41 52 |O PRINTABLE CHAR|
00008E60: 41 43 54 45 52 53 2E 20 20 D4 48 45 20 C3 D2 C3 |ACTERS. .HE ...|
00008E70: 20 53 45 51 55 45 4E 43 45 20 49 53 20 46 4F 52 | SEQUENCE IS FOR|
00008E80: 4D 45 44 20 46 52 4F 4D 20 54 48 45 20 31 36 2D |MED FROM THE 16-|
00008E90: 42 49 54 20 51 55 41 4E 54 49 54 59 0D 47 45 4E |BIT QUANTITY.GEN|
00008EA0: 45 52 41 54 45 44 20 42 59 20 54 48 45 20 C3 C3 |ERATED BY THE ..|
00008EB0: C9 D4 D4 2D 52 45 43 4F 4D 4D 45 4E 44 45 44 20 |...-RECOMMENDED |
00008EC0: 50 4F 4C 59 4E 4F 4D 49 41 4C 20 D8 28 31 36 29 |POLYNOMIAL .(16)|
00008ED0: 2B D8 28 31 32 29 2B D8 28 35 29 2B 31 20 57 48 |+.(12)+.(5)+1 WH|
00008EE0: 49 43 48 20 49 53 20 41 4C 53 4F 0D 55 53 45 44 |ICH IS ALSO.USED|
00008EF0: 20 49 4E 20 53 4F 4D 45 20 46 4F 52 4D 20 57 49 | IN SOME FORM WI|
00008F00: 54 48 20 4F 54 48 45 52 20 50 4F 50 55 4C 41 52 |TH OTHER POPULAR|
00008F10: 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E 20 54 45 | TRANSMISSION TE|
00008F20: 43 48 4E 49 51 55 45 53 2C 20 4C 49 4B 45 20 C9 |CHNIQUES, LIKE .|
00008F30: D3 CF 20 C8 C4 CC C3 20 41 4E 44 0D C9 C2 CD 20 |.. .... AND.... |
00008F40: D3 C4 CC C3 2E 20 D4 48 45 20 48 49 47 48 20 4F |..... .HE HIGH O|
00008F50: 52 44 45 52 20 34 20 42 49 54 53 20 4F 46 20 54 |RDER 4 BITS OF T|
00008F60: 48 45 20 C3 D2 C3 20 47 4F 20 49 4E 54 4F 20 54 |HE ... GO INTO T|
00008F70: 48 45 20 46 49 52 53 54 20 43 48 41 52 41 43 54 |HE FIRST CHARACT|
00008F80: 45 52 2C 20 54 48 45 0D 4D 49 44 44 4C 45 20 36 |ER, THE.MIDDLE 6|
00008F90: 20 49 4E 54 4F 20 54 48 45 20 53 45 43 4F 4E 44 | INTO THE SECOND|
00008FA0: 2C 20 41 4E 44 20 54 48 45 20 4C 4F 57 20 4F 52 |, AND THE LOW OR|
00008FB0: 44 45 52 20 36 20 49 4E 54 4F 20 54 48 45 20 54 |DER 6 INTO THE T|
00008FC0: 48 49 52 44 2E 20 D3 4F 4D 45 20 43 41 52 45 20 |HIRD. .OME CARE |
00008FD0: 4D 55 53 54 20 42 45 0D 54 41 4B 45 4E 20 49 4E |MUST BE.TAKEN IN|
00008FE0: 20 54 48 45 20 46 4F 52 4D 41 54 49 4F 4E 20 4F | THE FORMATION O|
00008FF0: 46 20 54 48 45 20 53 49 4E 47 4C 45 2D 43 48 41 |F THE SINGLE-CHA|
00009000: 52 41 43 54 45 52 20 42 4C 4F 43 4B 20 43 48 45 |RACTER BLOCK CHE|
00009010: 43 4B 2E 20 D3 49 4E 43 45 20 49 54 20 4D 55 53 |CK. .INCE IT MUS|
00009020: 54 20 42 45 0D 45 58 50 52 45 53 53 45 44 20 41 |T BE.EXPRESSED A|
00009030: 53 20 41 20 53 49 4E 47 4C 45 20 50 52 49 4E 54 |S A SINGLE PRINT|
00009040: 41 42 4C 45 20 43 48 41 52 41 43 54 45 52 2C 20 |ABLE CHARACTER, |
00009050: 56 41 4C 55 45 53 20 4F 46 20 54 48 45 20 48 49 |VALUES OF THE HI|
00009060: 47 48 20 4F 52 44 45 52 20 44 41 54 41 20 42 49 |GH ORDER DATA BI|
00009070: 54 53 0D 4D 41 59 20 42 45 20 4C 4F 53 54 2C 20 |TS.MAY BE LOST, |
00009080: 57 48 49 43 48 20 43 4F 55 4C 44 20 52 45 53 55 |WHICH COULD RESU|
00009090: 4C 54 20 49 4E 20 55 4E 44 45 54 45 43 54 45 44 |LT IN UNDETECTED|
000090A0: 20 45 52 52 4F 52 53 2C 20 45 53 50 45 43 49 41 | ERRORS, ESPECIA|
000090B0: 4C 4C 59 20 57 48 45 4E 20 54 52 41 4E 53 2D 0D |LLY WHEN TRANS-.|
000090C0: 46 45 52 52 49 4E 47 20 42 49 4E 41 52 59 20 46 |FERRING BINARY F|
000090D0: 49 4C 45 53 2E 20 20 D4 48 45 52 45 46 4F 52 45 |ILES. .HEREFORE|
000090E0: 2C 20 57 45 20 45 58 54 52 41 43 54 20 54 48 45 |, WE EXTRACT THE|
000090F0: 20 37 54 48 20 41 4E 44 20 38 54 48 20 42 49 54 | 7TH AND 8TH BIT|
00009100: 53 20 4F 46 20 54 48 45 20 53 55 4D 0D 41 4E 44 |S OF THE SUM.AND|
00009110: 20 41 44 44 20 54 48 45 4D 20 42 41 43 4B 20 54 | ADD THEM BACK T|
00009120: 4F 20 54 48 45 20 4C 4F 57 20 4F 52 44 45 52 20 |O THE LOW ORDER |
00009130: 42 49 54 53 3B 20 49 46 20 54 48 45 20 41 52 49 |BITS; IF THE ARI|
00009140: 54 48 4D 45 54 49 43 20 53 55 4D 20 4F 46 20 41 |THMETIC SUM OF A|
00009150: 4C 4C 20 54 48 45 0D 43 48 41 52 41 43 54 45 52 |LL THE.CHARACTER|
00009160: 53 20 49 53 20 D3 2C 20 54 48 45 4E 20 54 48 45 |S IS ., THEN THE|
00009170: 20 56 41 4C 55 45 20 4F 46 20 54 48 45 20 53 49 | VALUE OF THE SI|
00009180: 4E 47 4C 45 2D 43 48 41 52 41 43 54 45 52 20 CB |NGLE-CHARACTER .|
00009190: C5 D2 CD C9 D4 20 43 48 45 43 4B 53 55 4D 20 49 |..... CHECKSUM I|
000091A0: 53 0D 47 49 56 45 4E 20 42 59 0D 0D 20 20 28 D3 |S.GIVEN BY.. (.|
000091B0: 20 2B 20 D3 20 C1 CE C4 20 33 30 30 29 2F 31 30 | + . ... 300)/10|
000091C0: 30 29 29 20 C1 CE C4 20 37 37 0D 0D 28 4E 55 4D |0)) ... 77..(NUM|
000091D0: 42 45 52 53 20 41 52 45 20 49 4E 20 4F 43 54 41 |BERS ARE IN OCTA|
000091E0: 4C 20 4E 4F 54 41 54 49 4F 4E 29 2E 20 20 D4 48 |L NOTATION). .H|
000091F0: 49 53 20 45 4E 53 55 52 45 53 20 54 48 41 54 20 |IS ENSURES THAT |
00009200: 54 48 45 20 43 48 45 43 4B 53 55 4D 2C 20 54 45 |THE CHECKSUM, TE|
00009210: 52 53 45 20 54 48 4F 55 47 48 0D 49 54 20 49 53 |RSE THOUGH.IT IS|
00009220: 2C 20 52 45 46 4C 45 43 54 53 20 45 56 45 52 59 |, REFLECTS EVERY|
00009230: 20 42 49 54 20 46 52 4F 4D 20 45 56 45 52 59 20 | BIT FROM EVERY |
00009240: 43 48 41 52 41 43 54 45 52 20 49 4E 20 54 48 45 |CHARACTER IN THE|
00009250: 20 50 41 43 4B 45 54 2E 0D 0D D4 48 45 20 50 52 | PACKET....HE PR|
00009260: 4F 42 41 42 49 4C 49 54 59 20 54 48 41 54 20 41 |OBABILITY THAT A|
00009270: 4E 20 45 52 52 4F 52 20 57 49 4C 4C 20 4E 4F 54 |N ERROR WILL NOT|
00009280: 20 42 45 20 43 41 55 47 48 54 20 42 59 20 41 20 | BE CAUGHT BY A |
00009290: 43 4F 52 52 45 43 54 4C 59 20 54 52 41 4E 53 4D |CORRECTLY TRANSM|
000092A0: 49 54 54 45 44 0D 41 52 49 54 48 4D 45 54 49 43 |ITTED.ARITHMETIC|
000092B0: 20 43 48 45 43 4B 53 55 4D 20 49 53 20 54 48 45 | CHECKSUM IS THE|
000092C0: 20 52 41 54 49 4F 20 4F 46 20 54 48 45 20 4E 55 | RATIO OF THE NU|
000092D0: 4D 42 45 52 20 4F 46 20 50 4F 53 53 49 42 4C 45 |MBER OF POSSIBLE|
000092E0: 20 45 52 52 4F 52 53 20 54 48 41 54 20 43 41 4E | ERRORS THAT CAN|
000092F0: 43 45 4C 0D 45 41 43 48 20 4F 54 48 45 52 20 4F |CEL.EACH OTHER O|
00009300: 55 54 20 54 4F 20 54 48 45 20 54 4F 54 41 4C 20 |UT TO THE TOTAL |
00009310: 4E 55 4D 42 45 52 20 4F 46 20 50 4F 53 53 49 42 |NUMBER OF POSSIB|
00009320: 4C 45 20 45 52 52 4F 52 53 2C 20 57 48 49 43 48 |LE ERRORS, WHICH|
00009330: 20 57 4F 52 4B 53 20 4F 55 54 20 54 4F 20 42 45 | WORKS OUT TO BE|
00009340: 0D 53 4F 4D 45 54 48 49 4E 47 20 4C 49 4B 45 20 |.SOMETHING LIKE |
00009350: 31 2F 32 20 4E 2C 20 57 48 45 52 45 20 4E 20 49 |1/2 N, WHERE N I|
00009360: 53 20 54 48 45 20 4E 55 4D 42 45 52 20 4F 46 20 |S THE NUMBER OF |
00009370: 42 49 54 53 20 49 4E 20 54 48 45 20 43 48 45 43 |BITS IN THE CHEC|
00009380: 4B 53 55 4D 2C 20 41 53 53 55 4D 49 4E 47 0D 41 |KSUM, ASSUMING.A|
00009390: 4C 4C 20 45 52 52 4F 52 53 20 41 52 45 20 45 51 |LL ERRORS ARE EQ|
000093A0: 55 41 4C 4C 59 20 4C 49 4B 45 4C 59 2E 20 20 D4 |UALLY LIKELY. .|
000093B0: 48 49 53 20 49 53 20 31 2F 36 34 20 46 4F 52 20 |HIS IS 1/64 FOR |
000093C0: 54 48 45 20 53 49 4E 47 4C 45 20 43 48 41 52 41 |THE SINGLE CHARA|
000093D0: 43 54 45 52 20 43 48 45 43 4B 53 55 4D 2C 0D 41 |CTER CHECKSUM,.A|
000093E0: 4E 44 20 31 2F 34 30 39 36 20 46 4F 52 20 54 48 |ND 1/4096 FOR TH|
000093F0: 45 20 32 2D 43 48 41 52 41 43 54 45 52 20 43 48 |E 2-CHARACTER CH|
00009400: 45 43 4B 53 55 4D 2E 20 20 C2 55 54 20 54 48 45 |ECKSUM. .UT THE|
00009410: 20 50 52 4F 42 41 42 49 4C 49 54 59 20 54 48 41 | PROBABILITY THA|
00009420: 54 20 45 52 52 4F 52 53 20 57 49 4C 4C 0D 47 4F |T ERRORS WILL.GO|
00009430: 20 55 4E 44 45 54 45 43 54 45 44 20 42 59 20 54 | UNDETECTED BY T|
00009440: 48 49 53 20 4D 45 54 48 4F 44 20 28 55 4E 44 45 |HIS METHOD (UNDE|
00009450: 52 20 52 45 41 4C 20 43 4F 4E 44 49 54 49 4F 4E |R REAL CONDITION|
00009460: 53 29 20 43 41 4E 4E 4F 54 20 42 45 20 45 41 53 |S) CANNOT BE EAS|
00009470: 49 4C 59 20 44 45 52 49 56 45 44 2C 0D 42 45 43 |ILY DERIVED,.BEC|
00009480: 41 55 53 45 20 41 4C 4C 20 4B 49 4E 44 53 20 4F |AUSE ALL KINDS O|
00009490: 46 20 45 52 52 4F 52 53 20 41 52 45 20 4E 4F 54 |F ERRORS ARE NOT|
000094A0: 20 45 51 55 41 4C 4C 59 20 4C 49 4B 45 4C 59 2E | EQUALLY LIKELY.|
000094B0: 20 20 C1 20 31 36 2D 42 49 54 20 C3 D2 C3 20 57 | . 16-BIT ... W|
000094C0: 49 4C 4C 20 44 45 54 45 43 54 0D 41 4C 4C 20 53 |ILL DETECT.ALL S|
000094D0: 49 4E 47 4C 45 20 41 4E 44 20 44 4F 55 42 4C 45 |INGLE AND DOUBLE|
000094E0: 20 42 49 54 20 45 52 52 4F 52 53 2C 20 41 4C 4C | BIT ERRORS, ALL|
000094F0: 20 4D 45 53 53 41 47 45 53 20 57 49 54 48 20 41 | MESSAGES WITH A|
00009500: 4E 20 4F 44 44 20 4E 55 4D 42 45 52 20 4F 46 20 |N ODD NUMBER OF |
00009510: 42 49 54 53 20 49 4E 0D 45 52 52 4F 52 2C 20 41 |BITS IN.ERROR, A|
00009520: 4C 4C 20 45 52 52 4F 52 20 42 55 52 53 54 53 20 |LL ERROR BURSTS |
00009530: 53 48 4F 52 54 45 52 20 54 48 41 4E 20 31 36 20 |SHORTER THAN 16 |
00009540: 42 49 54 53 2C 20 41 4E 44 20 42 45 54 54 45 52 |BITS, AND BETTER|
00009550: 20 54 48 41 4E 20 39 39 2E 39 39 25 20 4F 46 20 | THAN 99.99% OF |
00009560: 4C 4F 4E 47 45 52 0D 42 55 52 53 54 53 2E 20 D4 |LONGER.BURSTS. .|
00009570: 48 45 53 45 20 50 52 4F 42 41 42 49 4C 49 54 49 |HESE PROBABILITI|
00009580: 45 53 20 41 4C 4C 20 41 53 53 55 4D 45 2C 20 4F |ES ALL ASSUME, O|
00009590: 46 20 43 4F 55 52 53 45 2C 20 54 48 41 54 20 54 |F COURSE, THAT T|
000095A0: 48 45 20 42 4C 4F 43 4B 20 43 48 45 43 4B 20 48 |HE BLOCK CHECK H|
000095B0: 41 53 0D 42 45 45 4E 20 49 44 45 4E 54 49 46 49 |AS.BEEN IDENTIFI|
000095C0: 45 44 20 43 4F 52 52 45 43 54 4C 59 2C 20 49 2E |ED CORRECTLY, I.|
000095D0: 45 2E 20 54 48 41 54 20 54 48 45 20 4C 45 4E 47 |E. THAT THE LENG|
000095E0: 54 48 20 46 49 45 4C 44 20 50 4F 49 4E 54 53 20 |TH FIELD POINTS |
000095F0: 54 4F 20 49 54 2C 20 41 4E 44 20 54 48 41 54 20 |TO IT, AND THAT |
00009600: 4E 4F 0D 49 4E 54 45 52 56 45 4E 49 4E 47 20 43 |NO.INTERVENING C|
00009610: 48 41 52 41 43 54 45 52 53 20 48 41 56 45 20 42 |HARACTERS HAVE B|
00009620: 45 45 4E 20 4C 4F 53 54 20 4F 52 20 53 50 55 52 |EEN LOST OR SPUR|
00009630: 49 4F 55 53 4C 59 20 41 44 44 45 44 2E 0D 0D C1 |IOUSLY ADDED....|
00009640: 20 46 49 4E 41 4C 20 4E 4F 54 45 20 4F 4E 20 50 | FINAL NOTE ON P|
00009650: 41 52 49 54 59 20 2D 20 41 20 50 41 52 49 54 59 |ARITY - A PARITY|
00009660: 20 42 49 54 20 4F 4E 20 45 41 43 48 20 43 48 41 | BIT ON EACH CHA|
00009670: 52 41 43 54 45 52 20 43 4F 4D 42 49 4E 45 44 20 |RACTER COMBINED |
00009680: 57 49 54 48 20 41 20 4C 4F 47 49 43 41 4C 0D 53 |WITH A LOGICAL.S|
00009690: 55 4D 20 4F 46 20 41 4C 4C 20 54 48 45 20 43 48 |UM OF ALL THE CH|
000096A0: 41 52 41 43 54 45 52 53 20 28 D6 D2 C3 20 41 4E |ARACTERS (... AN|
000096B0: 44 20 CC D2 C3 29 20 57 4F 55 4C 44 20 41 4C 4C |D ...) WOULD ALL|
000096C0: 4F 57 20 44 45 54 45 43 54 49 4F 4E 20 41 4E 44 |OW DETECTION AND|
000096D0: 20 43 4F 52 52 45 43 54 49 4F 4E 20 4F 46 0D 53 | CORRECTION OF.S|
000096E0: 49 4E 47 4C 45 2D 42 49 54 20 45 52 52 4F 52 53 |INGLE-BIT ERRORS|
000096F0: 20 57 49 54 48 4F 55 54 20 52 45 54 52 41 4E 53 | WITHOUT RETRANS|
00009700: 4D 49 53 53 49 4F 4E 20 42 59 20 50 49 4E 50 4F |MISSION BY PINPO|
00009710: 49 4E 54 49 4E 47 20 54 48 45 20 22 52 4F 57 22 |INTING THE "ROW"|
00009720: 20 41 4E 44 20 22 43 4F 4C 55 4D 4E 22 0D 4F 46 | AND "COLUMN".OF|
00009730: 20 54 48 45 20 42 41 44 20 42 49 54 2E 20 20 C2 | THE BAD BIT. .|
00009740: 55 54 20 43 4F 4E 54 52 4F 4C 20 4F 46 20 54 48 |UT CONTROL OF TH|
00009750: 45 20 50 41 52 49 54 59 20 42 49 54 20 43 41 4E |E PARITY BIT CAN|
00009760: 4E 4F 54 20 42 45 20 41 43 48 49 45 56 45 44 20 |NOT BE ACHIEVED |
00009770: 4F 4E 20 45 56 45 52 59 0D 53 59 53 54 45 4D 2C |ON EVERY.SYSTEM,|
00009780: 20 53 4F 20 57 45 20 55 53 45 20 54 48 45 20 50 | SO WE USE THE P|
00009790: 41 52 49 54 59 20 42 49 54 20 46 4F 52 20 42 49 |ARITY BIT FOR BI|
000097A0: 4E 41 52 59 20 44 41 54 41 20 57 48 45 4E 20 57 |NARY DATA WHEN W|
000097B0: 45 20 43 41 4E 2C 20 4F 52 20 53 55 52 52 45 4E |E CAN, OR SURREN|
000097C0: 44 45 52 20 49 54 0D 54 4F 20 54 48 45 20 43 4F |DER IT.TO THE CO|
000097D0: 4D 4D 55 4E 49 43 41 54 49 4F 4E 20 48 41 52 44 |MMUNICATION HARD|
000097E0: 57 41 52 45 20 49 46 20 57 45 20 4D 55 53 54 2E |WARE IF WE MUST.|
000097F0: 20 20 C9 46 20 57 45 20 48 41 56 45 20 55 53 45 | .F WE HAVE USE|
00009800: 20 4F 46 20 54 48 45 20 38 54 48 20 42 49 54 20 | OF THE 8TH BIT |
00009810: 46 4F 52 0D 44 41 54 41 2C 20 54 48 45 4E 20 49 |FOR.DATA, THEN I|
00009820: 54 20 49 53 20 46 49 47 55 52 45 44 20 49 4E 54 |T IS FIGURED INT|
00009830: 4F 20 54 48 45 20 42 4C 4F 43 4B 20 43 48 45 43 |O THE BLOCK CHEC|
00009840: 4B 3B 20 49 46 20 57 45 20 44 4F 20 4E 4F 54 2C |K; IF WE DO NOT,|
00009850: 20 54 48 45 4E 20 49 54 20 4D 55 53 54 20 42 45 | THEN IT MUST BE|
00009860: 0D 4F 4D 49 54 54 45 44 20 46 52 4F 4D 20 54 48 |.OMITTED FROM TH|
00009870: 45 20 42 4C 4F 43 4B 20 43 48 45 43 4B 20 49 4E |E BLOCK CHECK IN|
00009880: 20 43 41 53 45 20 49 54 20 48 41 53 20 42 45 45 | CASE IT HAS BEE|
00009890: 4E 20 43 48 41 4E 47 45 44 20 42 59 20 41 47 45 |N CHANGED BY AGE|
000098A0: 4E 54 53 20 42 45 59 4F 4E 44 20 54 48 45 0D 4B |NTS BEYOND THE.K|
000098B0: 4E 4F 57 4C 45 44 47 45 20 4F 52 20 43 4F 4E 54 |NOWLEDGE OR CONT|
000098C0: 52 4F 4C 20 4F 46 20 54 48 45 20 CB C5 D2 CD C9 |ROL OF THE .....|
000098D0: D4 20 50 52 4F 47 52 41 4D 2E 0D 0D 0D D0 41 43 |. PROGRAM.....AC|
000098E0: 4B 45 54 20 CC 41 59 4F 55 54 0D 0D CB C5 D2 CD |KET .AYOUT......|
000098F0: C9 D4 20 50 41 43 4B 45 54 53 20 48 41 56 45 20 |.. PACKETS HAVE |
00009900: 54 48 45 20 46 4F 52 4D 41 54 3A 0D 0D 2B 2D 2D |THE FORMAT:..+--|
00009910: 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D |----+-----------|
00009920: 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D |+-----------+---|
00009930: 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D |---+------------|
00009940: 2B 2D 2D 2D 2D 2D 2D 2D 2B 0D 21 20 CD C1 D2 CB |+-------+.! ....|
00009950: 20 21 20 43 48 41 52 28 CC C5 CE 29 20 21 20 43 | ! CHAR(...) ! C|
00009960: 48 41 52 28 D3 C5 D1 29 20 31 20 D4 D9 D0 C5 20 |HAR(...) 1 .... |
00009970: 21 20 20 20 20 C4 C1 D4 C1 20 20 20 20 21 20 C3 |! .... ! .|
00009980: C8 C5 C3 CB 20 21 0D 2B 2D 2D 2D 2D 2D 2D 2B 2D |.... !.+------+-|
00009990: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D |----------+-----|
000099A0: 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D |------+------+--|
000099B0: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D |----------+-----|
000099C0: 2D 2D 2B 0D 21 20 20 20 20 20 20 20 20 20 20 20 |--+.! |
000099D0: 20 20 20 20 20 20 20 21 20 20 20 20 20 20 20 20 | ! |
000099E0: 20 20 20 21 20 20 20 20 20 20 20 20 20 20 20 20 | ! |
000099F0: 20 20 20 20 20 20 20 21 20 20 20 20 20 20 20 21 | ! !|
00009A00: 0D 21 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |.! |
00009A10: 20 20 20 20 21 20 20 20 20 20 20 20 20 20 20 20 | ! |
00009A20: 2B 2D 2D 20 28 41 50 50 4C 49 43 41 54 49 4F 4E |+-- (APPLICATION|
00009A30: 29 20 2D 2D 2B 20 20 20 20 20 20 20 21 0D 21 20 |) --+ !.! |
00009A40: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00009A50: 20 21 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | ! |
00009A60: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00009A70: 20 21 20 20 20 20 20 20 20 21 0D 21 20 20 20 20 | ! !.! |
00009A80: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 2B 2D | +-|
00009A90: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 20 28 53 |------------- (S|
00009AA0: 45 53 53 49 4F 4E 29 20 2D 2D 2D 2D 2D 2D 2B 20 |ESSION) ------+ |
00009AB0: 20 20 20 20 20 20 21 0D 21 20 20 20 20 20 20 20 | !.! |
00009AC0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00009AD0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00009AE0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00009AF0: 20 20 20 21 0D 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D | !.+----------|
00009B00: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D |----------------|
00009B10: 2D 2D 2D 2D 2D 2D 2D 20 28 44 41 54 41 20 4C 49 |------- (DATA LI|
00009B20: 4E 4B 29 20 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D |NK) ------------|
00009B30: 2B 0D 0D 57 48 45 52 45 20 41 4C 4C 20 46 49 45 |+..WHERE ALL FIE|
00009B40: 4C 44 53 20 43 4F 4E 53 49 53 54 20 4F 46 20 C1 |LDS CONSIST OF .|
00009B50: D3 C3 C9 C9 20 43 48 41 52 41 43 54 45 52 53 2C |.... CHARACTERS,|
00009B60: 20 41 4E 44 20 54 48 45 20 43 48 41 52 20 46 55 | AND THE CHAR FU|
00009B70: 4E 43 54 49 4F 4E 20 43 4F 4E 56 45 52 54 53 20 |NCTION CONVERTS |
00009B80: 41 0D 4E 55 4D 42 45 52 20 49 4E 20 54 48 45 20 |A.NUMBER IN THE |
00009B90: 52 41 4E 47 45 20 30 2D 39 34 20 54 4F 20 41 20 |RANGE 0-94 TO A |
00009BA0: 50 52 49 4E 54 41 42 4C 45 20 C1 D3 C3 C9 C9 20 |PRINTABLE ..... |
00009BB0: 43 48 41 52 41 43 54 45 52 20 42 59 20 41 44 44 |CHARACTER BY ADD|
00009BC0: 49 4E 47 20 33 32 2E 20 C9 4E 20 54 45 52 4D 53 |ING 32. .N TERMS|
00009BD0: 0D 4F 46 20 54 48 45 20 C9 D3 CF 20 4E 45 54 57 |.OF THE ... NETW|
00009BE0: 4F 52 4B 20 52 45 46 45 52 45 4E 43 45 20 4D 4F |ORK REFERENCE MO|
00009BF0: 44 45 4C 20 2C 20 38 2D 42 49 54 20 42 59 54 45 |DEL , 8-BIT BYTE|
00009C00: 53 20 41 52 45 20 50 52 45 53 45 4E 54 45 44 20 |S ARE PRESENTED |
00009C10: 54 4F 20 54 48 45 20 CB C5 D2 CD C9 D4 0D 50 52 |TO THE .......PR|
00009C20: 4F 47 52 41 4D 20 42 59 20 54 48 45 20 48 41 52 |OGRAM BY THE HAR|
00009C30: 44 57 41 52 45 20 41 4E 44 20 4F 50 45 52 41 54 |DWARE AND OPERAT|
00009C40: 49 4E 47 20 53 59 53 54 45 4D 20 53 4F 46 54 57 |ING SYSTEM SOFTW|
00009C50: 41 52 45 20 43 4F 4D 50 52 49 53 49 4E 47 20 54 |ARE COMPRISING T|
00009C60: 48 45 20 50 48 59 53 49 43 41 4C 0D 4C 49 4E 4B |HE PHYSICAL.LINK|
00009C70: 20 4C 41 59 45 52 2E 20 C3 4F 52 52 45 43 54 20 | LAYER. .ORRECT |
00009C80: 54 52 41 4E 53 4D 49 53 53 49 4F 4E 20 49 53 20 |TRANSMISSION IS |
00009C90: 45 4E 53 55 52 45 44 20 42 59 20 54 48 45 20 50 |ENSURED BY THE P|
00009CA0: 41 43 4B 45 54 2D 4C 45 56 45 4C 20 52 4F 55 54 |ACKET-LEVEL ROUT|
00009CB0: 49 4E 45 53 20 54 48 41 54 0D 49 4D 50 4C 45 4D |INES THAT.IMPLEM|
00009CC0: 45 4E 54 20 54 48 45 20 44 41 54 41 20 4C 49 4E |ENT THE DATA LIN|
00009CD0: 4B 20 4C 41 59 45 52 20 55 53 49 4E 47 20 54 48 |K LAYER USING TH|
00009CE0: 45 20 4F 55 54 45 52 20 22 53 4B 49 4E 22 20 4F |E OUTER "SKIN" O|
00009CF0: 46 20 54 48 45 20 50 41 43 4B 45 54 20 2D 20 54 |F THE PACKET - T|
00009D00: 48 45 20 CD C1 D2 CB 2C 0D CC C5 CE 2C 20 41 4E |HE ....,...., AN|
00009D10: 44 20 C3 C8 C5 C3 CB 20 46 49 45 4C 44 53 2E 20 |D ..... FIELDS. |
00009D20: 20 D4 48 45 20 4E 45 54 57 4F 52 4B 20 41 4E 44 | .HE NETWORK AND|
00009D30: 20 54 52 41 4E 53 50 4F 52 54 20 4C 41 59 45 52 | TRANSPORT LAYER|
00009D40: 53 20 41 52 45 20 4D 4F 4F 54 2C 20 53 49 4E 43 |S ARE MOOT, SINC|
00009D50: 45 20 CB C5 D2 CD C9 D4 0D 49 53 20 41 20 50 4F |E .......IS A PO|
00009D60: 49 4E 54 2D 54 4F 2D 50 4F 49 4E 54 20 41 46 46 |INT-TO-POINT AFF|
00009D70: 41 49 52 2C 20 49 4E 20 57 48 49 43 48 20 54 48 |AIR, IN WHICH TH|
00009D80: 45 20 55 53 45 52 20 50 45 52 53 4F 4E 41 4C 4C |E USER PERSONALL|
00009D90: 59 20 4D 41 4B 45 53 20 41 4C 4C 20 54 48 45 20 |Y MAKES ALL THE |
00009DA0: 52 45 51 55 49 52 45 44 0D 43 4F 4E 4E 45 43 54 |REQUIRED.CONNECT|
00009DB0: 49 4F 4E 53 2E 20 20 D4 48 45 20 53 45 53 53 49 |IONS. .HE SESSI|
00009DC0: 4F 4E 20 4C 41 59 45 52 20 49 53 20 52 45 53 50 |ON LAYER IS RESP|
00009DD0: 4F 4E 53 49 42 4C 45 20 46 4F 52 20 52 45 51 55 |ONSIBLE FOR REQU|
00009DE0: 45 53 54 49 4E 47 20 52 45 54 52 41 4E 53 4D 49 |ESTING RETRANSMI|
00009DF0: 53 53 49 4F 4E 20 4F 46 0D 4D 49 53 53 49 4E 47 |SSION OF.MISSING|
00009E00: 20 50 41 43 4B 45 54 53 20 4F 52 20 49 47 4E 4F | PACKETS OR IGNO|
00009E10: 52 49 4E 47 20 52 45 44 55 4E 44 41 4E 54 20 4F |RING REDUNDANT O|
00009E20: 4E 45 53 2C 20 42 41 53 45 44 20 4F 4E 20 54 48 |NES, BASED ON TH|
00009E30: 45 20 D3 C5 D1 20 46 49 45 4C 44 3B 20 54 48 45 |E ... FIELD; THE|
00009E40: 20 50 52 45 53 45 4E 2D 0D 54 41 54 49 4F 4E 20 | PRESEN-.TATION |
00009E50: 4C 41 59 45 52 20 49 53 20 52 45 53 50 4F 4E 53 |LAYER IS RESPONS|
00009E60: 49 42 4C 45 20 46 4F 52 20 41 4E 59 20 44 41 54 |IBLE FOR ANY DAT|
00009E70: 41 20 43 4F 4E 56 45 52 53 49 4F 4E 53 20 28 C5 |A CONVERSIONS (.|
00009E80: C2 C3 C4 C9 C3 2F C1 D3 C3 C9 C9 2C 20 49 4E 53 |...../....., INS|
00009E90: 45 52 54 49 4F 4E 0D 4F 52 20 53 54 52 49 50 50 |ERTION.OR STRIPP|
00009EA0: 49 4E 47 20 4F 46 20 C3 D2 CC C6 53 2C 20 45 54 |ING OF ....S, ET|
00009EB0: 43 29 2E 20 20 C6 49 4E 41 4C 4C 59 2C 20 54 48 |C). .INALLY, TH|
00009EC0: 45 20 52 45 4D 41 49 4E 44 45 52 20 4F 46 20 54 |E REMAINDER OF T|
00009ED0: 48 45 20 50 41 43 4B 45 54 2C 20 54 48 45 20 D4 |HE PACKET, THE .|
00009EE0: D9 D0 C5 0D 41 4E 44 20 C4 C1 D4 C1 20 46 49 45 |....AND .... FIE|
00009EF0: 4C 44 53 2C 20 41 52 45 20 54 48 45 20 50 52 4F |LDS, ARE THE PRO|
00009F00: 56 49 4E 43 45 20 4F 46 20 54 48 45 20 41 50 50 |VINCE OF THE APP|
00009F10: 4C 49 43 41 54 49 4F 4E 20 4C 41 59 45 52 3B 20 |LICATION LAYER; |
00009F20: 4F 55 52 20 41 50 50 4C 49 43 41 54 49 4F 4E 2C |OUR APPLICATION,|
00009F30: 20 4F 46 0D 43 4F 55 52 53 45 2C 20 49 53 20 46 | OF.COURSE, IS F|
00009F40: 49 4C 45 20 54 52 41 4E 53 46 45 52 2E 20 20 C9 |ILE TRANSFER. .|
00009F50: 4E 20 41 4E 59 20 50 41 52 54 49 43 55 4C 41 52 |N ANY PARTICULAR|
00009F60: 20 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E 2C | IMPLEMENTATION,|
00009F70: 20 48 4F 57 45 56 45 52 2C 20 54 48 45 0D 4F 52 | HOWEVER, THE.OR|
00009F80: 47 41 4E 49 5A 41 54 49 4F 4E 20 4F 46 20 54 48 |GANIZATION OF TH|
00009F90: 45 20 50 52 4F 47 52 41 4D 20 4D 41 59 20 4E 4F |E PROGRAM MAY NO|
00009FA0: 54 20 53 54 52 49 43 54 4C 59 20 46 4F 4C 4C 4F |T STRICTLY FOLLO|
00009FB0: 57 20 54 48 49 53 20 4D 4F 44 45 4C 2E 20 20 C6 |W THIS MODEL. .|
00009FC0: 4F 52 20 49 4E 53 54 41 4E 43 45 2C 0D 53 49 4E |OR INSTANCE,.SIN|
00009FD0: 43 45 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E 20 |CE TRANSMISSION |
00009FE0: 49 53 20 41 4C 57 41 59 53 20 49 4E 20 53 54 52 |IS ALWAYS IN STR|
00009FF0: 45 41 4D 20 C1 D3 C3 C9 C9 2C 20 C9 C2 CD 20 49 |EAM ....., ... I|
0000A000: 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E 53 20 4D |MPLEMENTATIONS M|
0000A010: 55 53 54 20 43 4F 4E 56 45 52 54 0D 46 52 4F 4D |UST CONVERT.FROM|
0000A020: 20 C5 C2 C3 C4 C9 C3 20 41 4E 44 20 49 4E 53 45 | ...... AND INSE|
0000A030: 52 54 20 C3 D2 CC C6 53 20 42 45 46 4F 52 45 20 |RT ....S BEFORE |
0000A040: 43 48 45 43 4B 53 55 4D 20 43 4F 4D 50 55 54 41 |CHECKSUM COMPUTA|
0000A050: 54 49 4F 4E 2E 0D 0D D4 48 45 20 46 49 45 4C 44 |TION....HE FIELD|
0000A060: 53 20 4F 46 20 41 20 CB C5 D2 CD C9 D4 20 50 41 |S OF A ...... PA|
0000A070: 43 4B 45 54 20 41 52 45 20 41 53 20 46 4F 4C 4C |CKET ARE AS FOLL|
0000A080: 4F 57 53 3A 0D 0D D3 54 41 52 54 2D 4F 46 2D 50 |OWS:...TART-OF-P|
0000A090: 41 43 4B 45 54 20 43 48 41 52 41 43 54 45 52 2C |ACKET CHARACTER,|
0000A0A0: 20 4E 4F 52 4D 41 4C 4C 59 20 D3 CF C8 20 28 C1 | NORMALLY ... (.|
0000A0B0: D3 C3 C9 C9 20 31 29 2E 0D D4 48 45 20 4E 55 4D |.... 1)...HE NUM|
0000A0C0: 42 45 52 20 4F 46 20 C1 D3 C3 C9 C9 20 43 48 41 |BER OF ..... CHA|
0000A0D0: 52 41 43 54 45 52 53 2C 20 49 4E 43 4C 55 44 49 |RACTERS, INCLUDI|
0000A0E0: 4E 47 20 51 55 4F 54 49 4E 47 20 43 48 41 52 41 |NG QUOTING CHARA|
0000A0F0: 43 54 45 52 53 20 41 4E 44 20 54 48 45 20 43 48 |CTERS AND THE CH|
0000A100: 45 43 4B 53 55 4D 2C 0D 57 49 54 48 49 4E 20 54 |ECKSUM,.WITHIN T|
0000A110: 48 45 20 50 41 43 4B 45 54 20 54 48 41 54 20 46 |HE PACKET THAT F|
0000A120: 4F 4C 4C 4F 57 20 54 48 49 53 20 46 49 45 4C 44 |OLLOW THIS FIELD|
0000A130: 2C 20 49 4E 20 4F 54 48 45 52 20 57 4F 52 44 53 |, IN OTHER WORDS|
0000A140: 20 54 48 45 20 50 41 43 4B 45 54 20 4C 45 4E 47 | THE PACKET LENG|
0000A150: 54 48 0D 4D 49 4E 55 53 20 54 57 4F 2E 20 D3 49 |TH.MINUS TWO. .I|
0000A160: 4E 43 45 20 54 48 49 53 20 4E 55 4D 42 45 52 20 |NCE THIS NUMBER |
0000A170: 49 53 20 45 58 50 52 45 53 53 45 44 20 41 53 20 |IS EXPRESSED AS |
0000A180: 41 20 53 49 4E 47 4C 45 20 43 48 41 52 41 43 54 |A SINGLE CHARACT|
0000A190: 45 52 20 56 49 41 20 54 48 45 20 43 48 41 52 0D |ER VIA THE CHAR.|
0000A1A0: 46 55 4E 43 54 49 4F 4E 2C 20 50 41 43 4B 45 54 |FUNCTION, PACKET|
0000A1B0: 20 43 48 41 52 41 43 54 45 52 20 43 4F 55 4E 54 | CHARACTER COUNT|
0000A1C0: 53 20 4F 46 20 30 20 54 4F 20 39 34 20 41 52 45 |S OF 0 TO 94 ARE|
0000A1D0: 20 50 45 52 4D 49 54 54 45 44 2C 20 41 4E 44 20 | PERMITTED, AND |
0000A1E0: 39 36 20 49 53 20 54 48 45 0D 4D 41 58 49 4D 55 |96 IS THE.MAXIMU|
0000A1F0: 4D 20 54 4F 54 41 4C 20 50 41 43 4B 45 54 20 4C |M TOTAL PACKET L|
0000A200: 45 4E 47 54 48 2E 0D 0D D4 48 45 20 50 41 43 4B |ENGTH....HE PACK|
0000A210: 45 54 20 53 45 51 55 45 4E 43 45 20 4E 55 4D 42 |ET SEQUENCE NUMB|
0000A220: 45 52 2E 20 20 D4 48 45 20 53 45 51 55 45 4E 43 |ER. .HE SEQUENC|
0000A230: 45 20 4E 55 4D 42 45 52 53 20 22 57 52 41 50 53 |E NUMBERS "WRAPS|
0000A240: 20 41 52 4F 55 4E 44 22 20 54 4F 20 30 20 41 46 | AROUND" TO 0 AF|
0000A250: 54 45 52 0D 45 41 43 48 20 47 52 4F 55 50 20 4F |TER.EACH GROUP O|
0000A260: 46 20 36 34 20 50 41 43 4B 45 54 53 2E 0D 0D D4 |F 64 PACKETS....|
0000A270: 48 45 20 50 41 43 4B 45 54 20 54 59 50 45 2C 20 |HE PACKET TYPE, |
0000A280: 41 20 53 49 4E 47 4C 45 20 50 52 49 4E 54 41 42 |A SINGLE PRINTAB|
0000A290: 4C 45 20 C1 D3 C3 C9 C9 20 43 48 41 52 41 43 54 |LE ..... CHARACT|
0000A2A0: 45 52 2C 20 4F 4E 45 20 4F 46 20 54 48 45 20 46 |ER, ONE OF THE F|
0000A2B0: 4F 4C 4C 4F 57 49 4E 47 3A 0D 0D C4 41 54 41 0D |OLLOWING:...ATA.|
0000A2C0: C1 43 4B 4E 4F 57 4C 45 44 47 45 20 28 C1 C3 CB |.CKNOWLEDGE (...|
0000A2D0: 29 0D CE 45 47 41 54 49 56 45 20 C1 43 4B 4E 4F |)..EGATIVE .CKNO|
0000A2E0: 57 4C 45 44 47 45 20 28 CE C1 CB 29 0D D3 45 4E |WLEDGE (...)..EN|
0000A2F0: 44 20 C9 4E 49 54 49 41 54 45 20 28 D3 45 4E 44 |D .NITIATE (.END|
0000A300: 2D C9 4E 49 54 29 0D D2 45 43 45 49 56 45 20 C9 |-.NIT)..ECEIVE .|
0000A310: 4E 49 54 49 41 54 45 0D C2 52 45 41 4B 20 D4 52 |NITIATE..REAK .R|
0000A320: 41 4E 53 4D 49 53 53 49 4F 4E 20 28 C5 CF D4 29 |ANSMISSION (...)|
0000A330: 0D C6 49 4C 45 20 C8 45 41 44 45 52 0D C5 4E 44 |..ILE .EADER..ND|
0000A340: 20 4F 46 20 46 49 4C 45 20 28 C5 CF C6 29 0D C5 | OF FILE (...)..|
0000A350: 52 52 4F 52 0D 0D C7 45 4E 45 52 49 43 20 C3 4F |RROR...ENERIC .O|
0000A360: 4D 4D 41 4E 44 2E 20 20 C1 20 53 49 4E 47 4C 45 |MMAND. . SINGLE|
0000A370: 20 43 48 41 52 41 43 54 45 52 20 49 4E 20 54 48 | CHARACTER IN TH|
0000A380: 45 20 44 41 54 41 20 46 49 45 4C 44 2C 20 50 4F |E DATA FIELD, PO|
0000A390: 53 53 49 42 4C 59 20 46 4F 4C 4C 4F 57 45 44 20 |SSIBLY FOLLOWED |
0000A3A0: 42 59 0D 4F 50 45 52 41 4E 44 53 2C 20 52 45 51 |BY.OPERANDS, REQ|
0000A3B0: 55 45 53 54 53 20 48 4F 53 54 2D 49 4E 44 45 50 |UESTS HOST-INDEP|
0000A3C0: 45 4E 44 45 4E 54 20 52 45 4D 4F 54 45 20 45 58 |ENDENT REMOTE EX|
0000A3D0: 45 43 55 54 49 4F 4E 20 54 48 45 20 53 50 45 43 |ECUTION THE SPEC|
0000A3E0: 49 46 49 45 44 20 43 4F 4D 4D 41 4E 44 3A 0D 0D |IFIED COMMAND:..|
0000A3F0: CC 4F 47 4F 55 54 2C 20 C2 59 45 2E 0D C6 49 4E |.OGOUT, .YE...IN|
0000A400: 49 53 48 2C 20 42 55 54 20 44 4F 4E 27 54 20 4C |ISH, BUT DON'T L|
0000A410: 4F 47 4F 55 54 2E 0D C4 49 52 45 43 54 4F 52 59 |OGOUT...IRECTORY|
0000A420: 20 51 55 45 52 59 20 28 46 4F 4C 4C 4F 57 45 44 | QUERY (FOLLOWED|
0000A430: 20 42 59 20 4F 50 54 49 4F 4E 41 4C 20 46 49 4C | BY OPTIONAL FIL|
0000A440: 45 20 53 50 45 43 49 46 49 43 41 54 49 4F 4E 29 |E SPECIFICATION)|
0000A450: 2E 0D C4 49 53 4B 20 55 53 41 47 45 20 51 55 45 |...ISK USAGE QUE|
0000A460: 52 59 2E 0D C5 52 41 53 45 20 28 46 4F 4C 4C 4F |RY...RASE (FOLLO|
0000A470: 57 45 44 20 42 59 20 46 49 4C 45 20 53 50 45 43 |WED BY FILE SPEC|
0000A480: 49 46 49 43 41 54 49 4F 4E 29 2E 0D D4 59 50 45 |IFICATION)...YPE|
0000A490: 20 28 46 4F 4C 4C 4F 57 45 44 20 42 59 20 46 49 | (FOLLOWED BY FI|
0000A4A0: 4C 45 20 53 50 45 43 49 46 49 43 41 54 49 4F 4E |LE SPECIFICATION|
0000A4B0: 29 2E 0D D1 55 45 52 59 20 53 45 52 56 45 52 20 |)...UERY SERVER |
0000A4C0: 53 54 41 54 55 53 2E 0D 41 4E 44 20 4F 54 48 45 |STATUS..AND OTHE|
0000A4D0: 52 53 2E 0D 0D C8 4F 53 54 20 C3 4F 4D 4D 41 4E |RS....OST .OMMAN|
0000A4E0: 44 2E 20 20 D4 48 45 20 44 41 54 41 20 46 49 45 |D. .HE DATA FIE|
0000A4F0: 4C 44 20 43 4F 4E 54 41 49 4E 53 20 41 20 53 54 |LD CONTAINS A ST|
0000A500: 52 49 4E 47 20 54 4F 20 42 45 20 45 58 45 43 55 |RING TO BE EXECU|
0000A510: 54 45 44 20 41 53 20 41 20 53 59 53 54 45 4D 0D |TED AS A SYSTEM.|
0000A520: 44 45 50 45 4E 44 45 4E 54 20 28 4C 49 54 45 52 |DEPENDENT (LITER|
0000A530: 41 4C 29 20 43 4F 4D 4D 41 4E 44 20 42 59 20 54 |AL) COMMAND BY T|
0000A540: 48 45 20 48 4F 53 54 2E 0D 0D D4 45 58 54 20 44 |HE HOST....EXT D|
0000A550: 49 53 50 4C 41 59 20 48 45 41 44 45 52 2C 20 54 |ISPLAY HEADER, T|
0000A560: 4F 20 49 4E 44 49 43 41 54 45 20 54 48 45 20 41 |O INDICATE THE A|
0000A570: 52 52 49 56 41 4C 20 4F 46 20 54 45 58 54 20 54 |RRIVAL OF TEXT T|
0000A580: 4F 20 42 45 20 44 49 53 50 4C 41 59 45 44 20 4F |O BE DISPLAYED O|
0000A590: 4E 20 54 48 45 0D 53 43 52 45 45 4E 2C 20 46 4F |N THE.SCREEN, FO|
0000A5A0: 52 20 49 4E 53 54 41 4E 43 45 20 41 53 20 54 48 |R INSTANCE AS TH|
0000A5B0: 45 20 52 45 53 55 4C 54 20 4F 46 20 41 20 47 45 |E RESULT OF A GE|
0000A5C0: 4E 45 52 49 43 20 4F 52 20 48 4F 53 54 20 43 4F |NERIC OR HOST CO|
0000A5D0: 4D 4D 41 4E 44 20 45 58 45 43 55 54 45 44 20 41 |MMAND EXECUTED A|
0000A5E0: 54 20 54 48 45 0D 4F 54 48 45 52 20 45 4E 44 2E |T THE.OTHER END.|
0000A5F0: 20 CF 50 45 52 41 54 49 4F 4E 20 49 53 20 45 58 | .PERATION IS EX|
0000A600: 41 43 54 4C 59 20 4C 49 4B 45 20 41 20 46 49 4C |ACTLY LIKE A FIL|
0000A610: 45 20 54 52 41 4E 53 46 45 52 2E 0D 0D C4 C1 D4 |E TRANSFER......|
0000A620: C1 20 20 20 D4 48 45 20 22 43 4F 4E 54 45 4E 54 |. .HE "CONTENT|
0000A630: 53 22 20 4F 46 20 54 48 45 20 50 41 43 4B 45 54 |S" OF THE PACKET|
0000A640: 2C 20 49 46 20 41 4E 59 20 43 4F 4E 54 45 4E 54 |, IF ANY CONTENT|
0000A650: 53 20 41 52 45 20 52 45 51 55 49 52 45 44 20 49 |S ARE REQUIRED I|
0000A660: 4E 20 54 48 45 20 47 49 56 45 4E 0D 54 59 50 45 |N THE GIVEN.TYPE|
0000A670: 20 4F 46 20 50 41 43 4B 45 54 2C 20 49 4E 54 45 | OF PACKET, INTE|
0000A680: 52 50 52 45 54 45 44 20 41 43 43 4F 52 44 49 4E |RPRETED ACCORDIN|
0000A690: 47 20 54 4F 20 54 48 45 20 50 41 43 4B 45 54 20 |G TO THE PACKET |
0000A6A0: 54 59 50 45 2E 20 20 CE 4F 4E 50 52 49 4E 54 41 |TYPE. .ONPRINTA|
0000A6B0: 42 4C 45 20 C1 D3 C3 C9 C9 0D 43 48 41 52 41 43 |BLE ......CHARAC|
0000A6C0: 54 45 52 53 20 41 52 45 20 50 52 45 46 49 58 45 |TERS ARE PREFIXE|
0000A6D0: 44 20 57 49 54 48 20 51 55 4F 54 45 20 43 48 41 |D WITH QUOTE CHA|
0000A6E0: 52 41 43 54 45 52 53 20 41 4E 44 20 54 48 45 4E |RACTERS AND THEN|
0000A6F0: 20 22 55 4E 43 4F 4E 54 52 4F 4C 4C 49 46 49 45 | "UNCONTROLLIFIE|
0000A700: 44 22 2E 0D C3 48 41 52 41 43 54 45 52 53 20 57 |D"...HARACTERS W|
0000A710: 49 54 48 20 54 48 45 20 38 54 48 20 42 49 54 20 |ITH THE 8TH BIT |
0000A720: 53 45 54 20 4D 41 59 20 41 4C 53 4F 20 42 45 20 |SET MAY ALSO BE |
0000A730: 50 52 45 46 49 58 45 44 2C 20 41 4E 44 20 41 20 |PREFIXED, AND A |
0000A740: 52 45 50 45 41 54 45 44 20 43 48 41 52 41 43 54 |REPEATED CHARACT|
0000A750: 45 52 0D 43 41 4E 20 42 45 20 50 52 45 46 49 58 |ER.CAN BE PREFIX|
0000A760: 45 44 20 42 59 20 41 20 43 4F 55 4E 54 2E 20 C1 |ED BY A COUNT. .|
0000A770: 20 50 52 45 46 49 58 45 44 20 53 45 51 55 45 4E | PREFIXED SEQUEN|
0000A780: 43 45 20 4D 41 59 20 4E 4F 54 20 42 45 20 42 52 |CE MAY NOT BE BR|
0000A790: 4F 4B 45 4E 20 41 43 52 4F 53 53 0D 50 41 43 4B |OKEN ACROSS.PACK|
0000A7A0: 45 54 53 2E 0D 0D C3 C8 C5 C3 CB 20 20 D4 48 45 |ETS........ .HE|
0000A7B0: 20 42 4C 4F 43 4B 20 43 48 45 43 4B 20 53 45 51 | BLOCK CHECK SEQ|
0000A7C0: 55 45 4E 43 45 2C 20 42 41 53 45 44 20 4F 4E 20 |UENCE, BASED ON |
0000A7D0: 41 4C 4C 20 54 48 45 20 43 48 41 52 41 43 54 45 |ALL THE CHARACTE|
0000A7E0: 52 53 20 49 4E 20 54 48 45 20 50 41 43 4B 45 54 |RS IN THE PACKET|
0000A7F0: 0D 42 45 54 57 45 45 4E 2C 20 42 55 54 20 4E 4F |.BETWEEN, BUT NO|
0000A800: 54 20 49 4E 43 4C 55 44 49 4E 47 2C 20 54 48 45 |T INCLUDING, THE|
0000A810: 20 4D 41 52 4B 20 41 4E 44 20 54 48 45 20 43 48 | MARK AND THE CH|
0000A820: 45 43 4B 20 49 54 53 45 4C 46 2C 20 4F 4E 45 2C |ECK ITSELF, ONE,|
0000A830: 20 54 57 4F 2C 20 4F 52 20 54 48 52 45 45 0D 43 | TWO, OR THREE.C|
0000A840: 48 41 52 41 43 54 45 52 53 20 49 4E 20 4C 45 4E |HARACTERS IN LEN|
0000A850: 47 54 48 20 41 53 20 44 45 53 43 52 49 42 45 44 |GTH AS DESCRIBED|
0000A860: 20 41 42 4F 56 45 2C 20 45 41 43 48 20 43 48 41 | ABOVE, EACH CHA|
0000A870: 52 41 43 54 45 52 20 54 52 41 4E 53 46 4F 52 4D |RACTER TRANSFORM|
0000A880: 45 44 20 42 59 20 43 48 41 52 2E 0D CE 4F 52 4D |ED BY CHAR...ORM|
0000A890: 41 4C 4C 59 2C 20 54 48 45 20 53 49 4E 47 4C 45 |ALLY, THE SINGLE|
0000A8A0: 2D 43 48 41 52 41 43 54 45 52 20 43 48 45 43 4B |-CHARACTER CHECK|
0000A8B0: 53 55 4D 20 49 53 20 55 53 45 44 2E 0D 0D D4 48 |SUM IS USED....H|
0000A8C0: 45 20 50 41 43 4B 45 54 20 4D 41 59 20 42 45 20 |E PACKET MAY BE |
0000A8D0: 46 4F 4C 4C 4F 57 45 44 20 42 59 20 41 4E 59 20 |FOLLOWED BY ANY |
0000A8E0: 4C 49 4E 45 20 54 45 52 4D 49 4E 41 54 4F 52 20 |LINE TERMINATOR |
0000A8F0: 52 45 51 55 49 52 45 44 20 42 59 20 54 48 45 20 |REQUIRED BY THE |
0000A900: 48 4F 53 54 2C 0D 43 41 52 52 49 41 47 45 20 52 |HOST,.CARRIAGE R|
0000A910: 45 54 55 52 4E 20 28 C1 D3 C3 C9 C9 20 31 35 29 |ETURN (..... 15)|
0000A920: 20 42 59 20 44 45 46 41 55 4C 54 2E 20 20 CC 49 | BY DEFAULT. .I|
0000A930: 4E 45 20 54 45 52 4D 49 4E 41 54 4F 52 53 20 41 |NE TERMINATORS A|
0000A940: 52 45 20 4E 4F 54 20 50 41 52 54 20 4F 46 20 54 |RE NOT PART OF T|
0000A950: 48 45 0D 50 41 43 4B 45 54 2C 20 41 4E 44 20 41 |HE.PACKET, AND A|
0000A960: 52 45 20 4E 4F 54 20 49 4E 43 4C 55 44 45 44 20 |RE NOT INCLUDED |
0000A970: 49 4E 20 54 48 45 20 43 4F 55 4E 54 20 4F 52 20 |IN THE COUNT OR |
0000A980: 43 48 45 43 4B 53 55 4D 2E 20 20 D4 45 52 4D 49 |CHECKSUM. .ERMI|
0000A990: 4E 41 54 4F 52 53 20 41 52 45 20 4E 4F 54 0D 4E |NATORS ARE NOT.N|
0000A9A0: 45 43 45 53 53 41 52 59 20 54 4F 20 54 48 45 20 |ECESSARY TO THE |
0000A9B0: 50 52 4F 54 4F 43 4F 4C 2C 20 41 4E 44 20 41 52 |PROTOCOL, AND AR|
0000A9C0: 45 20 49 4E 56 49 53 49 42 4C 45 20 54 4F 20 49 |E INVISIBLE TO I|
0000A9D0: 54 2C 20 41 53 20 41 52 45 20 41 4E 59 20 43 48 |T, AS ARE ANY CH|
0000A9E0: 41 52 41 43 54 45 52 53 20 54 48 41 54 0D 4D 41 |ARACTERS THAT.MA|
0000A9F0: 59 20 41 50 50 45 41 52 20 42 45 54 57 45 45 4E |Y APPEAR BETWEEN|
0000AA00: 20 50 41 43 4B 45 54 53 2E 20 20 C9 46 20 41 20 | PACKETS. .F A |
0000AA10: 48 4F 53 54 20 43 41 4E 4E 4F 54 20 44 4F 20 53 |HOST CANNOT DO S|
0000AA20: 49 4E 47 4C 45 20 43 48 41 52 41 43 54 45 52 20 |INGLE CHARACTER |
0000AA30: 49 4E 50 55 54 20 46 52 4F 4D 20 41 0D D4 D4 D9 |INPUT FROM A....|
0000AA40: 20 4C 49 4E 45 2C 20 54 48 45 4E 20 41 20 54 45 | LINE, THEN A TE|
0000AA50: 52 4D 49 4E 41 54 4F 52 20 57 49 4C 4C 20 42 45 |RMINATOR WILL BE|
0000AA60: 20 52 45 51 55 49 52 45 44 20 46 4F 52 20 54 48 | REQUIRED FOR TH|
0000AA70: 41 54 20 48 4F 53 54 2E 20 C8 45 52 45 20 41 52 |AT HOST. .ERE AR|
0000AA80: 45 20 53 4F 4D 45 0D 53 41 4D 50 4C 45 20 CB C5 |E SOME.SAMPLE ..|
0000AA90: D2 CD C9 D4 20 44 41 54 41 20 50 41 43 4B 45 54 |.... DATA PACKET|
0000AAA0: 53 3A 0D 0D 5E C1 C5 22 C4 20 20 20 CE 4F 20 43 |S:..^..". .O C|
0000AAB0: 45 4C 45 53 54 49 41 4C 20 42 4F 44 59 20 48 41 |ELESTIAL BODY HA|
0000AAC0: 53 20 52 45 51 55 49 52 45 44 20 CA 0D 5E C1 C5 |S REQUIRED ..^..|
0000AAD0: 23 C4 41 53 20 4D 55 43 48 20 4C 41 42 4F 52 20 |#.AS MUCH LABOR |
0000AAE0: 46 4F 52 20 54 48 45 20 53 54 55 44 59 20 4F 46 |FOR THE STUDY OF|
0000AAF0: 20 49 54 53 23 0D 5E C1 C5 24 C4 23 CD 23 CA 4D | ITS#.^..$.#.#.M|
0000AB00: 4F 54 49 4F 4E 20 41 53 20 54 48 45 20 4D 4F 4F |OTION AS THE MOO|
0000AB10: 4E 2E 20 20 D3 49 4E 43 45 20 C3 4C 41 C1 0D 5E |N. .INCE .LA..^|
0000AB20: C1 C5 25 C4 49 52 41 55 4C 54 20 28 31 37 34 37 |..%.IRAULT (1747|
0000AB30: 29 2C 20 57 48 4F 20 49 4E 44 49 43 41 54 45 44 |), WHO INDICATED|
0000AB40: 20 41 20 57 41 59 37 0D 5E C1 C5 26 C4 20 4F 46 | A WAY7.^..&. OF|
0000AB50: 23 CD 23 CA 43 4F 4E 53 54 52 55 43 54 49 4E 47 |#.#.CONSTRUCTING|
0000AB60: 20 41 20 54 48 45 4F 52 59 20 43 4F 4E 54 41 35 | A THEORY CONTA5|
0000AB70: 0D 0D D4 48 45 20 22 5E C1 22 20 52 45 50 52 45 |...HE "^." REPRE|
0000AB80: 53 45 4E 54 53 20 54 48 45 20 D3 CF C8 20 28 4F |SENTS THE ... (O|
0000AB90: 52 20 C3 4F 4E 54 52 4F 4C 2D C1 29 20 43 48 41 |R .ONTROL-.) CHA|
0000ABA0: 52 41 43 54 45 52 2E 20 C9 4E 20 54 48 45 20 46 |RACTER. .N THE F|
0000ABB0: 49 4E 41 4C 20 50 41 43 4B 45 54 0D 53 48 4F 57 |INAL PACKET.SHOW|
0000ABC0: 4E 2C 20 22 C5 22 20 49 53 20 54 48 45 20 4C 45 |N, "." IS THE LE|
0000ABD0: 4E 47 54 48 2E 20 20 D4 48 45 20 C1 D3 C3 C9 C9 |NGTH. .HE .....|
0000ABE0: 20 56 41 4C 55 45 20 4F 46 20 54 48 45 20 22 C5 | VALUE OF THE ".|
0000ABF0: 22 20 43 48 41 52 41 43 54 45 52 20 49 53 20 36 |" CHARACTER IS 6|
0000AC00: 39 2C 20 4C 45 53 53 20 33 32 0D 28 54 48 45 20 |9, LESS 32.(THE |
0000AC10: 55 4E 43 48 41 52 20 54 52 41 4E 53 46 4F 52 4D |UNCHAR TRANSFORM|
0000AC20: 41 54 49 4F 4E 2C 20 57 48 49 43 48 20 49 53 20 |ATION, WHICH IS |
0000AC30: 54 48 45 20 4F 50 50 4F 53 49 54 45 20 4F 46 20 |THE OPPOSITE OF |
0000AC40: 43 48 41 52 29 20 47 49 56 45 53 20 41 20 4C 45 |CHAR) GIVES A LE|
0000AC50: 4E 47 54 48 20 4F 46 0D 33 37 2E 20 D4 48 45 20 |NGTH OF.37. .HE |
0000AC60: 4E 45 58 54 20 43 48 41 52 41 43 54 45 52 20 54 |NEXT CHARACTER T|
0000AC70: 45 4C 4C 53 20 54 48 45 20 50 41 43 4B 45 54 20 |ELLS THE PACKET |
0000AC80: 53 45 51 55 45 4E 43 45 20 4E 55 4D 42 45 52 2C |SEQUENCE NUMBER,|
0000AC90: 20 49 4E 20 54 48 49 53 20 43 41 53 45 20 36 20 | IN THIS CASE 6 |
0000ACA0: 28 22 26 22 20 49 53 0D C1 D3 C3 C9 C9 20 33 38 |("&" IS...... 38|
0000ACB0: 29 2E 20 D4 48 45 20 4E 45 58 54 20 49 53 20 54 |). .HE NEXT IS T|
0000ACC0: 48 45 20 50 41 43 4B 45 54 20 54 59 50 45 20 22 |HE PACKET TYPE "|
0000ACD0: C4 22 20 46 4F 52 20 C4 41 54 41 2E 20 20 D4 48 |." FOR .ATA. .H|
0000ACE0: 45 20 4E 45 58 54 20 43 48 41 52 41 43 54 45 52 |E NEXT CHARACTER|
0000ACF0: 53 2C 0D 22 40 51 3C 20 4F 46 23 CD 23 CA 43 4F |S,."@Q< OF#.#.CO|
0000AD00: 4E 53 54 52 55 43 54 49 4E 47 20 41 20 54 48 45 |NSTRUCTING A THE|
0000AD10: 4F 52 59 20 43 4F 4E 54 41 3E 22 2C 20 46 4F 52 |ORY CONTA>", FOR|
0000AD20: 4D 20 54 48 45 20 44 41 54 41 3B 20 4E 4F 54 45 |M THE DATA; NOTE|
0000AD30: 20 54 48 45 20 50 52 45 46 49 58 45 44 0D 43 41 | THE PREFIXED.CA|
0000AD40: 52 52 49 41 47 45 20 52 45 54 55 52 4E 20 41 4E |RRIAGE RETURN AN|
0000AD50: 44 20 4C 49 4E 45 20 46 45 45 44 2E 20 D4 48 45 |D LINE FEED. .HE|
0000AD60: 20 46 49 4E 41 4C 20 43 48 41 52 41 43 54 45 52 | FINAL CHARACTER|
0000AD70: 2C 20 22 35 22 20 49 53 20 54 48 45 20 43 48 45 |, "5" IS THE CHE|
0000AD80: 43 4B 53 55 4D 2C 0D 57 48 49 43 48 20 52 45 50 |CKSUM,.WHICH REP|
0000AD90: 52 45 53 45 4E 54 53 20 54 48 45 20 4E 55 4D 42 |RESENTS THE NUMB|
0000ADA0: 45 52 20 32 31 20 28 41 4C 4C 20 4E 55 4D 42 45 |ER 21 (ALL NUMBE|
0000ADB0: 52 53 20 49 4E 20 54 48 49 53 20 50 41 52 41 47 |RS IN THIS PARAG|
0000ADC0: 52 41 50 48 20 41 52 45 20 49 4E 20 44 45 43 49 |RAPH ARE IN DECI|
0000ADD0: 4D 41 4C 29 2E 0D 0D 0D C5 46 46 45 43 54 53 20 |MAL).....FFECTS |
0000ADE0: 4F 46 20 D0 41 43 4B 45 54 20 C3 4F 52 52 55 50 |OF .ACKET .ORRUP|
0000ADF0: 54 49 4F 4E 0D 0D D7 48 41 54 20 41 52 45 20 54 |TION...HAT ARE T|
0000AE00: 48 45 20 43 4F 4E 53 45 51 55 45 4E 43 45 53 20 |HE CONSEQUENCES |
0000AE10: 4F 46 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E 20 |OF TRANSMISSION |
0000AE20: 45 52 52 4F 52 53 20 49 4E 20 54 48 45 20 56 41 |ERRORS IN THE VA|
0000AE30: 52 49 4F 55 53 20 46 49 45 4C 44 53 3F 20 20 C9 |RIOUS FIELDS? .|
0000AE40: 46 0D 54 48 45 20 D3 CF C8 20 49 53 20 47 41 52 |F.THE ... IS GAR|
0000AE50: 42 4C 45 44 2C 20 54 48 45 20 50 41 43 4B 45 54 |BLED, THE PACKET|
0000AE60: 20 57 49 4C 4C 20 42 45 20 54 52 45 41 54 45 44 | WILL BE TREATED|
0000AE70: 20 41 53 20 49 4E 54 45 52 50 41 43 4B 45 54 20 | AS INTERPACKET |
0000AE80: 47 41 52 42 41 47 45 2C 20 41 4E 44 0D 4C 4F 53 |GARBAGE, AND.LOS|
0000AE90: 54 2E 20 C9 46 20 41 4E 59 20 4F 54 48 45 52 20 |T. .F ANY OTHER |
0000AEA0: 43 48 41 52 41 43 54 45 52 20 57 49 54 48 49 4E |CHARACTER WITHIN|
0000AEB0: 20 54 48 45 20 50 41 43 4B 45 54 20 49 53 20 47 | THE PACKET IS G|
0000AEC0: 41 52 42 4C 45 44 20 49 4E 54 4F 20 D3 CF C8 2C |ARBLED INTO ...,|
0000AED0: 20 54 48 45 20 43 55 52 52 45 4E 54 0D 50 41 43 | THE CURRENT.PAC|
0000AEE0: 4B 45 54 20 57 49 4C 4C 20 42 45 20 44 49 53 43 |KET WILL BE DISC|
0000AEF0: 41 52 44 45 44 2C 20 41 4E 44 20 41 20 4E 45 57 |ARDED, AND A NEW|
0000AF00: 20 28 53 50 55 52 49 4F 55 53 29 20 50 41 43 4B | (SPURIOUS) PACK|
0000AF10: 45 54 20 44 45 54 45 43 54 45 44 2E 20 C9 46 20 |ET DETECTED. .F |
0000AF20: 54 48 45 20 4C 45 4E 47 54 48 0D 49 53 20 47 41 |THE LENGTH.IS GA|
0000AF30: 52 42 4C 45 44 20 49 4E 54 4F 20 41 20 53 4D 41 |RBLED INTO A SMA|
0000AF40: 4C 4C 45 52 20 4E 55 4D 42 45 52 2C 20 54 48 45 |LLER NUMBER, THE|
0000AF50: 4E 20 41 20 43 48 41 52 41 43 54 45 52 20 46 52 |N A CHARACTER FR|
0000AF60: 4F 4D 20 54 48 45 20 44 41 54 41 20 46 49 45 4C |OM THE DATA FIEL|
0000AF70: 44 20 57 49 4C 4C 20 42 45 0D 4D 49 53 49 4E 54 |D WILL BE.MISINT|
0000AF80: 45 52 50 52 45 54 45 44 20 41 53 20 54 48 45 20 |ERPRETED AS THE |
0000AF90: 43 48 45 43 4B 53 55 4D 3B 20 49 46 20 4C 41 52 |CHECKSUM; IF LAR|
0000AFA0: 47 45 52 2C 20 54 48 45 4E 20 54 48 45 20 50 52 |GER, THEN THE PR|
0000AFB0: 4F 47 52 41 4D 20 57 49 4C 4C 20 50 52 4F 42 41 |OGRAM WILL PROBA|
0000AFC0: 42 4C 59 0D 42 45 43 4F 4D 45 20 53 54 55 43 4B |BLY.BECOME STUCK|
0000AFD0: 20 54 52 59 49 4E 47 20 54 4F 20 49 4E 50 55 54 | TRYING TO INPUT|
0000AFE0: 20 43 48 41 52 41 43 54 45 52 53 20 54 48 41 54 | CHARACTERS THAT|
0000AFF0: 20 57 49 4C 4C 20 4E 4F 54 20 42 45 20 53 45 4E | WILL NOT BE SEN|
0000B000: 54 20 55 4E 54 49 4C 20 4F 4E 45 20 53 49 44 45 |T UNTIL ONE SIDE|
0000B010: 20 4F 52 0D 54 48 45 20 4F 54 48 45 52 20 54 49 | OR.THE OTHER TI|
0000B020: 4D 45 53 20 4F 55 54 20 41 4E 44 20 52 45 54 52 |MES OUT AND RETR|
0000B030: 41 4E 53 4D 49 54 53 2E 20 20 C9 46 20 54 48 45 |ANSMITS. .F THE|
0000B040: 20 53 45 51 55 45 4E 43 45 20 4E 55 4D 42 45 52 | SEQUENCE NUMBER|
0000B050: 2C 20 54 59 50 45 2C 20 41 4E 59 20 4F 46 20 54 |, TYPE, ANY OF T|
0000B060: 48 45 0D 44 41 54 41 20 43 48 41 52 41 43 54 45 |HE.DATA CHARACTE|
0000B070: 52 53 2C 20 4F 52 20 54 48 45 20 43 48 45 43 4B |RS, OR THE CHECK|
0000B080: 53 55 4D 20 49 54 53 45 4C 46 20 49 53 20 47 41 |SUM ITSELF IS GA|
0000B090: 52 42 4C 45 44 2C 20 54 48 45 20 43 48 45 43 4B |RBLED, THE CHECK|
0000B0A0: 53 55 4D 20 53 48 4F 55 4C 44 20 42 45 0D 57 52 |SUM SHOULD BE.WR|
0000B0B0: 4F 4E 47 2E 20 C9 46 20 43 48 41 52 41 43 54 45 |ONG. .F CHARACTE|
0000B0C0: 52 53 20 41 52 45 20 4C 4F 53 54 2C 20 54 48 45 |RS ARE LOST, THE|
0000B0D0: 52 45 20 57 49 4C 4C 20 4D 4F 53 54 20 4C 49 4B |RE WILL MOST LIK|
0000B0E0: 45 4C 59 20 42 45 20 41 20 54 49 4D 45 4F 55 54 |ELY BE A TIMEOUT|
0000B0F0: 2E 20 C9 46 20 4E 4F 49 53 45 0D 43 48 41 52 41 |. .F NOISE.CHARA|
0000B100: 43 54 45 52 53 20 41 52 45 20 53 50 4F 4E 54 41 |CTERS ARE SPONTA|
0000B110: 4E 45 4F 55 53 4C 59 20 47 45 4E 45 52 41 54 45 |NEOUSLY GENERATE|
0000B120: 44 2C 20 54 48 45 59 20 57 49 4C 4C 20 42 45 20 |D, THEY WILL BE |
0000B130: 49 47 4E 4F 52 45 44 20 49 46 20 54 48 45 59 20 |IGNORED IF THEY |
0000B140: 41 52 45 0D 42 45 54 57 45 45 4E 20 50 41 43 4B |ARE.BETWEEN PACK|
0000B150: 45 54 53 2C 20 4F 52 20 57 49 4C 4C 20 43 41 55 |ETS, OR WILL CAU|
0000B160: 53 45 20 54 48 45 20 57 52 4F 4E 47 20 43 48 41 |SE THE WRONG CHA|
0000B170: 52 41 43 54 45 52 20 54 4F 20 42 45 20 49 4E 54 |RACTER TO BE INT|
0000B180: 45 52 50 52 45 54 45 44 20 41 53 20 54 48 45 0D |ERPRETED AS THE.|
0000B190: 43 48 45 43 4B 53 55 4D 20 49 46 20 54 48 45 59 |CHECKSUM IF THEY|
0000B1A0: 20 43 4F 4D 45 20 44 55 52 49 4E 47 20 50 41 43 | COME DURING PAC|
0000B1B0: 4B 45 54 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E |KET TRANSMISSION|
0000B1C0: 2E 20 CD 4F 53 54 20 4B 49 4E 44 53 20 4F 46 20 |. .OST KINDS OF |
0000B1D0: 45 52 52 4F 52 53 20 41 52 45 0D 43 41 55 47 48 |ERRORS ARE.CAUGH|
0000B1E0: 54 20 42 59 20 54 48 45 20 43 48 45 43 4B 53 55 |T BY THE CHECKSU|
0000B1F0: 4D 20 43 4F 4D 50 41 52 49 53 4F 4E 2C 20 41 4E |M COMPARISON, AN|
0000B200: 44 20 41 52 45 20 48 41 4E 44 4C 45 44 20 42 59 |D ARE HANDLED BY|
0000B210: 20 49 4D 4D 45 44 49 41 54 45 20 52 45 54 52 41 | IMMEDIATE RETRA|
0000B220: 4E 53 4D 49 53 53 49 4F 4E 2E 0D D4 49 4D 45 4F |NSMISSION...IMEO|
0000B230: 55 54 53 20 41 52 45 20 4D 4F 52 45 20 43 4F 53 |UTS ARE MORE COS|
0000B240: 54 4C 59 20 42 45 43 41 55 53 45 20 54 48 45 20 |TLY BECAUSE THE |
0000B250: 4C 49 4E 45 20 53 49 54 53 20 49 44 4C 45 20 46 |LINE SITS IDLE F|
0000B260: 4F 52 20 54 48 45 20 54 49 4D 45 4F 55 54 20 50 |OR THE TIMEOUT P|
0000B270: 45 52 49 4F 44 2E 0D D4 48 45 20 50 41 43 4B 45 |ERIOD...HE PACKE|
0000B280: 54 20 44 45 53 49 47 4E 20 4D 49 4E 49 4D 49 5A |T DESIGN MINIMIZ|
0000B290: 45 53 20 54 48 45 20 4E 45 43 45 53 53 49 54 59 |ES THE NECESSITY|
0000B2A0: 20 46 4F 52 20 54 49 4D 45 4F 55 54 53 20 44 55 | FOR TIMEOUTS DU|
0000B2B0: 45 20 54 4F 20 50 41 43 4B 45 54 0D 43 4F 52 52 |E TO PACKET.CORR|
0000B2C0: 55 50 54 49 4F 4E 3A 20 54 48 45 20 4F 4E 4C 59 |UPTION: THE ONLY|
0000B2D0: 20 46 49 45 4C 44 53 20 54 48 41 54 20 43 41 4E | FIELDS THAT CAN|
0000B2E0: 20 42 45 20 43 4F 52 52 55 50 54 45 44 20 54 4F | BE CORRUPTED TO|
0000B2F0: 20 43 41 55 53 45 20 41 20 54 49 4D 45 4F 55 54 | CAUSE A TIMEOUT|
0000B300: 20 41 52 45 20 54 48 45 0D D3 CF C8 20 41 4E 44 | ARE THE.... AND|
0000B310: 20 54 48 45 20 50 41 43 4B 45 54 20 4C 45 4E 47 | THE PACKET LENG|
0000B320: 54 48 2C 20 41 4E 44 20 54 48 45 20 4C 41 54 54 |TH, AND THE LATT|
0000B330: 45 52 20 4F 4E 4C 59 20 48 41 4C 46 20 54 48 45 |ER ONLY HALF THE|
0000B340: 20 54 49 4D 45 2E 20 CC 4F 53 54 20 43 48 41 52 | TIME. .OST CHAR|
0000B350: 41 43 54 45 52 53 2C 0D 48 4F 57 45 56 45 52 2C |ACTERS,.HOWEVER,|
0000B360: 20 43 41 4E 20 50 52 4F 44 55 43 45 20 54 48 45 | CAN PRODUCE THE|
0000B370: 20 53 41 4D 45 20 45 46 46 45 43 54 20 28 41 53 | SAME EFFECT (AS|
0000B380: 20 54 48 45 59 20 57 4F 55 4C 44 20 57 49 54 48 | THEY WOULD WITH|
0000B390: 20 41 20 46 49 58 45 44 2D 4C 45 4E 47 54 48 20 | A FIXED-LENGTH |
0000B3A0: 42 4C 4F 43 4B 0D 50 52 4F 54 4F 43 4F 4C 29 2E |BLOCK.PROTOCOL).|
0000B3B0: 20 20 C8 41 44 20 41 20 44 49 53 54 49 4E 47 55 | .AD A DISTINGU|
0000B3C0: 49 53 48 45 44 20 45 4E 44 2D 4F 46 2D 50 41 43 |ISHED END-OF-PAC|
0000B3D0: 4B 45 54 20 43 48 41 52 41 43 54 45 52 20 42 45 |KET CHARACTER BE|
0000B3E0: 45 4E 20 55 53 45 44 20 52 41 54 48 45 52 20 54 |EN USED RATHER T|
0000B3F0: 48 41 4E 20 41 0D 4C 45 4E 47 54 48 20 46 49 45 |HAN A.LENGTH FIE|
0000B400: 4C 44 2C 20 54 48 45 4E 20 54 48 45 52 45 20 57 |LD, THEN THERE W|
0000B410: 4F 55 4C 44 20 42 45 20 41 20 54 49 4D 45 4F 55 |OULD BE A TIMEOU|
0000B420: 54 20 45 56 45 52 59 20 54 49 4D 45 20 49 54 20 |T EVERY TIME IT |
0000B430: 57 41 53 20 43 4F 52 52 55 50 54 45 44 2E 20 20 |WAS CORRUPTED. |
0000B440: C9 54 20 49 53 0D 41 4C 57 41 59 53 20 42 45 54 |.T IS.ALWAYS BET|
0000B450: 54 45 52 20 54 4F 20 52 45 54 52 41 4E 53 4D 49 |TER TO RETRANSMI|
0000B460: 54 20 49 4D 4D 45 44 49 41 54 45 4C 59 20 54 48 |T IMMEDIATELY TH|
0000B470: 41 4E 20 54 4F 20 54 49 4D 45 20 4F 55 54 2E 0D |AN TO TIME OUT..|
0000B480: 0D 0D D0 52 4F 54 4F 43 4F 4C 0D 3D 3D 3D 3D 3D |...ROTOCOL.=====|
0000B490: 3D 3D 3D 0D 0D D4 48 45 20 CB C5 D2 CD C9 D4 20 |===...HE ...... |
0000B4A0: 50 52 4F 54 4F 43 4F 4C 20 43 41 4E 20 42 45 20 |PROTOCOL CAN BE |
0000B4B0: 44 45 53 43 52 49 42 45 44 20 41 53 20 41 20 53 |DESCRIBED AS A S|
0000B4C0: 45 54 20 4F 46 20 53 54 41 54 45 53 20 41 4E 44 |ET OF STATES AND|
0000B4D0: 20 41 20 53 45 54 20 4F 46 0D 54 52 41 4E 53 49 | A SET OF.TRANSI|
0000B4E0: 54 49 4F 4E 53 20 54 48 41 54 20 44 45 46 49 4E |TIONS THAT DEFIN|
0000B4F0: 45 2C 20 46 4F 52 20 41 20 47 49 56 45 4E 20 45 |E, FOR A GIVEN E|
0000B500: 56 45 4E 54 2C 20 57 48 41 54 20 41 43 54 49 4F |VENT, WHAT ACTIO|
0000B510: 4E 20 54 4F 20 54 41 4B 45 20 41 4E 44 20 57 48 |N TO TAKE AND WH|
0000B520: 41 54 20 4E 45 57 0D 53 54 41 54 45 20 54 4F 20 |AT NEW.STATE TO |
0000B530: 43 48 41 4E 47 45 20 54 4F 2E 20 D4 48 45 20 49 |CHANGE TO. .HE I|
0000B540: 4E 48 45 52 45 4E 54 20 53 49 4D 50 4C 49 43 49 |NHERENT SIMPLICI|
0000B550: 54 59 20 4F 46 20 54 48 45 20 44 45 53 49 47 4E |TY OF THE DESIGN|
0000B560: 2C 20 50 41 52 54 49 43 55 4C 41 52 4C 59 20 54 |, PARTICULARLY T|
0000B570: 48 45 0D 52 45 51 55 49 52 45 4D 45 4E 54 20 54 |HE.REQUIREMENT T|
0000B580: 48 41 54 20 45 41 43 48 20 50 41 43 4B 45 54 20 |HAT EACH PACKET |
0000B590: 4D 55 53 54 20 42 45 20 41 43 4B 4E 4F 57 4C 45 |MUST BE ACKNOWLE|
0000B5A0: 44 47 45 44 2C 20 52 45 44 55 43 45 53 20 54 48 |DGED, REDUCES TH|
0000B5B0: 45 20 4E 55 4D 42 45 52 20 4F 46 20 53 54 41 54 |E NUMBER OF STAT|
0000B5C0: 45 53 0D 41 4E 44 20 41 43 54 49 4F 4E 53 2C 20 |ES.AND ACTIONS, |
0000B5D0: 41 4E 44 20 54 48 45 20 41 4D 4F 55 4E 54 20 4F |AND THE AMOUNT O|
0000B5E0: 46 20 53 54 41 54 45 20 49 4E 46 4F 52 4D 41 54 |F STATE INFORMAT|
0000B5F0: 49 4F 4E 20 54 48 41 54 20 4D 55 53 54 20 42 45 |ION THAT MUST BE|
0000B600: 20 4D 41 49 4E 54 41 49 4E 45 44 2C 20 54 4F 20 | MAINTAINED, TO |
0000B610: 41 0D 4D 49 4E 49 4D 55 4D 2E 20 C8 45 52 45 20 |A.MINIMUM. .ERE |
0000B620: 49 53 20 41 20 53 49 4D 50 4C 49 46 49 45 44 20 |IS A SIMPLIFIED |
0000B630: 56 45 52 53 49 4F 4E 20 4F 46 20 41 20 53 54 41 |VERSION OF A STA|
0000B640: 54 45 20 44 49 41 47 52 41 4D 20 46 4F 52 20 CB |TE DIAGRAM FOR .|
0000B650: C5 D2 CD C9 D4 20 52 45 43 45 49 56 49 4E 47 20 |..... RECEIVING |
0000B660: 41 0D 46 49 4C 45 3A 0D 0D 20 20 20 20 20 20 20 |A.FILE:.. |
0000B670: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B680: 20 20 20 20 20 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D | +----------|
0000B690: 2D 2D 2D 2D 2B 0D 20 20 20 20 20 20 20 20 20 20 |----+. |
0000B6A0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B6B0: 20 20 21 20 D2 45 43 45 49 56 45 20 C9 4E 49 54 | ! .ECEIVE .NIT|
0000B6C0: 20 21 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 | !. |
0000B6D0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 2B | +|
0000B6E0: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D |--------------+.|
0000B6F0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B700: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B710: 20 20 20 20 21 0D 20 20 20 20 20 20 20 20 20 20 | !. |
0000B720: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B730: 20 20 20 20 20 20 20 20 20 20 21 20 28 C7 45 54 | ! (.ET|
0000B740: 20 D3 45 4E 44 20 C9 4E 49 54 20 D0 41 43 4B 45 | .END .NIT .ACKE|
0000B750: 54 29 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 |T). |
0000B760: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B770: 20 20 20 20 20 20 20 21 0D 20 20 20 20 20 20 20 | !. |
0000B780: 20 20 20 20 28 C7 45 54 20 C5 CF D4 20 D0 41 43 | (.ET ... .AC|
0000B790: 4B 45 54 29 20 20 20 20 20 20 20 20 20 D6 0D 20 |KET) .. |
0000B7A0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B7B0: 20 20 20 20 20 20 20 20 20 20 20 2B 2D 2D 2D 2D | +----|
0000B7C0: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 28 C4 |----------+. (.|
0000B7D0: 4F 4E 45 29 20 3C 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D |ONE) <----------|
0000B7E0: 2D 2D 2D 2D 2D 2D 2D 2D 21 20 D2 45 43 45 49 56 |--------! .ECEIV|
0000B7F0: 45 20 C6 49 4C 45 20 21 3C 2D 2D 2D 2D 2D 2D 2D |E .ILE !<-------|
0000B800: 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 20 20 20 20 |--------+. |
0000B810: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B820: 20 20 20 20 20 20 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D | +---------|
0000B830: 2D 2D 2D 2D 2D 2B 20 20 20 20 20 20 20 20 20 20 |-----+ |
0000B840: 20 20 20 20 20 20 21 0D 20 20 20 20 20 20 20 20 | !. |
0000B850: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B860: 20 20 20 20 20 20 20 20 20 20 20 20 21 20 20 20 | ! |
0000B870: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B880: 20 20 20 20 21 0D 20 20 20 20 20 20 20 20 20 20 | !. |
0000B890: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B8A0: 20 20 20 20 20 20 20 20 20 20 21 20 28 C7 45 54 | ! (.ET|
0000B8B0: 20 C6 49 4C 45 20 20 20 20 20 20 20 20 20 20 20 | .ILE |
0000B8C0: 20 20 21 20 28 C7 45 54 20 C5 CF C6 20 D0 41 43 | ! (.ET ... .AC|
0000B8D0: 4B 45 54 29 0D 20 20 20 20 20 20 20 20 20 20 20 |KET). |
0000B8E0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B8F0: 20 20 20 20 20 20 20 20 20 21 20 20 C8 45 41 44 | ! .EAD|
0000B900: 45 52 20 D0 41 43 4B 45 54 29 20 20 20 20 20 20 |ER .ACKET) |
0000B910: 20 21 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 | !. |
0000B920: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B930: 20 20 20 20 20 20 20 D6 20 20 20 20 20 20 20 20 | . |
0000B940: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 | !|
0000B950: 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |. |
0000B960: 20 20 20 20 20 20 20 20 20 20 20 20 20 2B 2D 2D | +--|
0000B970: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 20 20 20 |------------+ |
0000B980: 20 20 20 20 20 20 20 20 20 20 20 20 20 21 0D 20 | !. |
0000B990: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B9A0: 20 20 20 2B 2D 2D 2D 2D 2D 2D 3E 21 20 D2 45 43 | +------>! .EC|
0000B9B0: 45 49 56 45 20 C4 41 54 41 20 21 2D 2D 2D 2D 2D |EIVE .ATA !-----|
0000B9C0: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 20 |-----------+. |
0000B9D0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000B9E0: 20 21 20 20 20 20 20 20 20 2B 2D 2D 2D 2D 2D 2D | ! +------|
0000B9F0: 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 20 20 20 20 |--------+. |
0000BA00: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 20 | ! |
0000BA10: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 0D | !.|
0000BA20: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000BA30: 20 20 20 20 21 20 20 20 20 20 20 20 20 20 20 20 | ! |
0000BA40: 20 20 20 20 21 20 28 C7 45 54 20 C4 41 54 41 20 | ! (.ET .ATA |
0000BA50: D0 41 43 4B 45 54 29 0D 20 20 20 20 20 20 20 20 |.ACKET). |
0000BA60: 20 20 20 20 20 20 20 20 20 20 20 20 21 20 20 20 | ! |
0000BA70: 20 20 20 20 20 20 20 20 20 20 20 20 21 0D 20 20 | !. |
0000BA80: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000BA90: 20 20 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D | +-------------|
0000BAA0: 2D 2D 2B 0D 0D C6 4F 52 20 53 49 4D 50 4C 49 43 |--+...OR SIMPLIC|
0000BAB0: 49 54 59 2C 20 53 4F 4D 45 20 54 52 41 4E 53 49 |ITY, SOME TRANSI|
0000BAC0: 54 49 4F 4E 53 20 41 52 45 20 4E 4F 54 20 53 48 |TIONS ARE NOT SH|
0000BAD0: 4F 57 4E 20 49 4E 20 54 48 45 20 44 49 41 47 52 |OWN IN THE DIAGR|
0000BAE0: 41 4D 3A 0D 0D C9 46 20 49 4E 20 41 4E 59 20 53 |AM:...F IN ANY S|
0000BAF0: 54 41 54 45 20 41 20 42 41 44 20 50 41 43 4B 45 |TATE A BAD PACKE|
0000BB00: 54 20 49 53 20 52 45 43 45 49 56 45 44 20 4F 52 |T IS RECEIVED OR|
0000BB10: 20 41 20 54 49 4D 45 4F 55 54 20 4F 43 43 55 52 | A TIMEOUT OCCUR|
0000BB20: 53 2C 20 41 20 4E 55 4C 4C 20 54 52 41 4E 53 49 |S, A NULL TRANSI|
0000BB30: 54 49 4F 4E 0D 42 41 43 4B 20 54 4F 20 54 48 45 |TION.BACK TO THE|
0000BB40: 20 53 41 4D 45 20 53 54 41 54 45 20 4F 43 43 55 | SAME STATE OCCU|
0000BB50: 52 53 2C 20 57 49 54 48 20 41 20 CE C1 CB 20 46 |RS, WITH A ... F|
0000BB60: 4F 52 20 54 48 45 20 45 58 50 45 43 54 45 44 20 |OR THE EXPECTED |
0000BB70: 50 41 43 4B 45 54 2E 20 C9 4E 20 41 4E 59 20 53 |PACKET. .N ANY S|
0000BB80: 54 41 54 45 0D 41 4E 20 45 52 52 4F 52 20 4D 41 |TATE.AN ERROR MA|
0000BB90: 59 20 4F 43 43 55 52 20 54 48 41 54 20 43 41 4E |Y OCCUR THAT CAN|
0000BBA0: 20 43 41 55 53 45 20 54 48 45 20 54 52 41 4E 53 | CAUSE THE TRANS|
0000BBB0: 46 45 52 20 54 4F 20 54 45 52 4D 49 4E 41 54 45 |FER TO TERMINATE|
0000BBC0: 2E 20 20 C6 4F 52 20 49 4E 53 54 41 4E 43 45 2C |. .OR INSTANCE,|
0000BBD0: 20 54 48 45 0D 54 41 52 47 45 54 20 44 49 53 4B | THE.TARGET DISK|
0000BBE0: 20 4D 49 47 48 54 20 46 49 4C 4C 20 55 50 2E 20 | MIGHT FILL UP. |
0000BBF0: 20 D4 48 45 20 53 49 44 45 20 54 48 41 54 20 45 | .HE SIDE THAT E|
0000BC00: 4E 43 4F 55 4E 54 45 52 45 44 20 54 48 45 20 45 |NCOUNTERED THE E|
0000BC10: 52 52 4F 52 20 53 45 4E 44 53 20 41 4E 20 45 52 |RROR SENDS AN ER|
0000BC20: 52 4F 52 0D 50 41 43 4B 45 54 2C 20 43 4F 4E 54 |ROR.PACKET, CONT|
0000BC30: 41 49 4E 49 4E 47 20 41 4E 20 49 4E 46 4F 52 4D |AINING AN INFORM|
0000BC40: 41 54 49 56 45 20 45 52 52 4F 52 20 4D 45 53 53 |ATIVE ERROR MESS|
0000BC50: 41 47 45 2C 20 41 4E 44 20 51 55 49 54 53 2E 20 |AGE, AND QUITS. |
0000BC60: D5 50 4F 4E 20 52 45 43 45 49 50 54 20 4F 46 20 |.PON RECEIPT OF |
0000BC70: 54 48 45 0D 45 52 52 4F 52 20 50 41 43 4B 45 54 |THE.ERROR PACKET|
0000BC80: 2C 20 54 48 45 20 4F 54 48 45 52 20 53 49 44 45 |, THE OTHER SIDE|
0000BC90: 20 44 49 53 50 4C 41 59 53 20 54 48 45 20 4D 45 | DISPLAYS THE ME|
0000BCA0: 53 53 41 47 45 20 4F 4E 20 54 48 45 20 53 43 52 |SSAGE ON THE SCR|
0000BCB0: 45 45 4E 20 28 49 46 20 49 54 20 49 53 20 49 4E |EEN (IF IT IS IN|
0000BCC0: 0D 43 4F 4E 54 52 4F 4C 20 4F 46 20 54 48 45 20 |.CONTROL OF THE |
0000BCD0: 53 43 52 45 45 4E 29 20 41 4E 44 20 41 4C 53 4F |SCREEN) AND ALSO|
0000BCE0: 20 51 55 49 54 53 2E 20 C1 43 54 49 4F 4E 53 20 | QUITS. .CTIONS |
0000BCF0: 54 48 41 54 20 41 52 45 20 54 41 4B 45 4E 20 4F |THAT ARE TAKEN O|
0000BD00: 4E 20 45 41 43 48 0D 54 52 41 4E 53 49 54 49 4F |N EACH.TRANSITIO|
0000BD10: 4E 2C 20 53 55 43 48 20 41 53 20 4F 50 45 4E 49 |N, SUCH AS OPENI|
0000BD20: 4E 47 20 41 20 46 49 4C 45 20 57 48 45 4E 20 41 |NG A FILE WHEN A|
0000BD30: 20 C6 49 4C 45 20 C8 45 41 44 45 52 20 50 41 43 | .ILE .EADER PAC|
0000BD40: 4B 45 54 20 49 53 20 52 45 43 45 49 56 45 44 2C |KET IS RECEIVED,|
0000BD50: 20 41 52 45 0D 4E 4F 54 20 53 48 4F 57 4E 3B 20 | ARE.NOT SHOWN; |
0000BD60: 49 4E 20 50 41 52 54 49 43 55 4C 41 52 20 45 41 |IN PARTICULAR EA|
0000BD70: 43 48 20 50 41 43 4B 45 54 20 53 55 43 43 45 53 |CH PACKET SUCCES|
0000BD80: 53 46 55 4C 4C 59 20 52 45 43 45 49 56 45 44 20 |SFULLY RECEIVED |
0000BD90: 49 53 20 C1 C3 CB 27 44 2E 0D 0D D4 48 45 20 52 |IS ...'D....HE R|
0000BDA0: 45 43 45 49 56 45 52 20 53 54 41 52 54 53 20 4F |ECEIVER STARTS O|
0000BDB0: 55 54 20 49 4E 20 D2 45 43 45 49 56 45 20 C9 4E |UT IN .ECEIVE .N|
0000BDC0: 49 54 20 53 54 41 54 45 20 41 4E 44 20 57 41 49 |IT STATE AND WAI|
0000BDD0: 54 53 20 46 4F 52 20 54 48 45 20 4F 54 48 45 52 |TS FOR THE OTHER|
0000BDE0: 20 53 49 44 45 20 54 4F 0D 53 45 4E 44 20 41 20 | SIDE TO.SEND A |
0000BDF0: D3 45 4E 44 2D C9 4E 49 54 20 50 41 43 4B 45 54 |.END-.NIT PACKET|
0000BE00: 2E 20 C9 46 20 41 4E 59 20 4F 54 48 45 52 20 4B |. .F ANY OTHER K|
0000BE10: 49 4E 44 20 4F 46 20 50 41 43 4B 45 54 20 49 53 |IND OF PACKET IS|
0000BE20: 20 52 45 43 45 49 56 45 44 2C 20 4F 52 20 54 48 | RECEIVED, OR TH|
0000BE30: 45 20 D3 45 4E 44 2D 0D C9 4E 49 54 20 44 4F 45 |E .END-..NIT DOE|
0000BE40: 53 20 4E 4F 54 20 41 52 52 49 56 45 20 57 49 54 |S NOT ARRIVE WIT|
0000BE50: 48 49 4E 20 54 48 45 20 54 49 4D 45 4F 55 54 20 |HIN THE TIMEOUT |
0000BE60: 49 4E 54 45 52 56 41 4C 2C 20 41 20 CE C1 CB 20 |INTERVAL, A ... |
0000BE70: 49 53 20 53 45 4E 54 2E 20 D4 49 4D 45 4F 55 54 |IS SENT. .IMEOUT|
0000BE80: 53 20 4F 52 0D CE C1 CB 53 20 43 41 4E 20 4F 43 |S OR....S CAN OC|
0000BE90: 43 55 52 20 55 50 20 54 4F 20 41 20 54 48 52 45 |CUR UP TO A THRE|
0000BEA0: 53 48 4F 4C 44 20 57 48 49 43 48 2C 20 57 48 45 |SHOLD WHICH, WHE|
0000BEB0: 4E 20 45 58 43 45 45 44 45 44 20 46 4F 52 20 41 |N EXCEEDED FOR A|
0000BEC0: 20 50 41 52 54 49 43 55 4C 41 52 20 50 41 43 4B | PARTICULAR PACK|
0000BED0: 45 54 2C 0D 43 41 55 53 45 53 20 54 48 45 20 50 |ET,.CAUSES THE P|
0000BEE0: 52 4F 54 4F 43 4F 4C 20 54 4F 20 41 53 53 55 4D |ROTOCOL TO ASSUM|
0000BEF0: 45 20 54 48 41 54 20 54 48 45 20 43 4F 4E 4E 45 |E THAT THE CONNE|
0000BF00: 43 54 49 4F 4E 20 48 41 53 20 42 45 43 4F 4D 45 |CTION HAS BECOME|
0000BF10: 20 55 4E 55 53 41 42 4C 45 2C 20 41 4E 44 20 54 | UNUSABLE, AND T|
0000BF20: 4F 0D 47 49 56 45 20 55 50 2E 0D 0D C1 46 54 45 |O.GIVE UP....FTE|
0000BF30: 52 20 54 48 45 20 D3 45 4E 44 2D C9 4E 49 54 20 |R THE .END-.NIT |
0000BF40: 41 52 52 49 56 45 53 2C 20 54 48 45 20 53 54 41 |ARRIVES, THE STA|
0000BF50: 54 45 20 42 45 43 4F 4D 45 53 20 D2 45 43 45 49 |TE BECOMES .ECEI|
0000BF60: 56 45 20 C6 49 4C 45 3B 20 CB C5 D2 CD C9 D4 20 |VE .ILE; ...... |
0000BF70: 57 41 49 54 53 20 46 4F 52 0D 41 20 C6 49 4C 45 |WAITS FOR.A .ILE|
0000BF80: 20 C8 45 41 44 45 52 20 50 41 43 4B 45 54 20 43 | .EADER PACKET C|
0000BF90: 4F 4E 54 41 49 4E 49 4E 47 20 54 48 45 20 4E 41 |ONTAINING THE NA|
0000BFA0: 4D 45 20 4F 46 20 54 48 45 20 46 49 4C 45 20 57 |ME OF THE FILE W|
0000BFB0: 48 49 43 48 20 49 53 20 54 4F 20 43 4F 4D 45 2E |HICH IS TO COME.|
0000BFC0: 20 20 D7 48 45 4E 0D 54 48 45 20 46 49 4C 45 20 | .HEN.THE FILE |
0000BFD0: 48 45 41 44 45 52 20 41 52 52 49 56 45 53 2C 20 |HEADER ARRIVES, |
0000BFE0: CB C5 D2 CD C9 D4 20 4F 50 45 4E 53 20 41 20 4E |...... OPENS A N|
0000BFF0: 45 57 20 46 49 4C 45 20 55 53 49 4E 47 20 54 48 |EW FILE USING TH|
0000C000: 45 20 4E 41 4D 45 20 50 52 4F 56 49 44 45 44 0D |E NAME PROVIDED.|
0000C010: 28 50 45 52 48 41 50 53 20 54 52 41 4E 53 46 4F |(PERHAPS TRANSFO|
0000C020: 52 4D 45 44 20 54 4F 20 53 55 49 54 20 4C 4F 43 |RMED TO SUIT LOC|
0000C030: 41 4C 20 4E 41 4D 49 4E 47 20 43 4F 4E 56 45 4E |AL NAMING CONVEN|
0000C040: 54 49 4F 4E 53 2C 20 4F 52 20 54 4F 20 41 56 4F |TIONS, OR TO AVO|
0000C050: 49 44 20 41 20 4E 41 4D 45 0D 43 4F 4C 4C 49 53 |ID A NAME.COLLIS|
0000C060: 49 4F 4E 29 2C 20 41 4E 44 20 53 57 49 54 43 48 |ION), AND SWITCH|
0000C070: 45 53 20 54 4F 20 D2 45 43 45 49 56 45 20 C4 41 |ES TO .ECEIVE .A|
0000C080: 54 41 20 53 54 41 54 45 2E 20 20 CB C5 D2 CD C9 |TA STATE. .....|
0000C090: D4 20 54 48 45 4E 20 52 45 43 45 49 56 45 53 20 |. THEN RECEIVES |
0000C0A0: 54 48 45 0D 43 4F 4E 54 45 4E 54 53 20 4F 46 20 |THE.CONTENTS OF |
0000C0B0: 54 48 45 20 46 49 4C 45 2C 20 55 4E 54 49 4C 20 |THE FILE, UNTIL |
0000C0C0: 41 4E 20 C5 CF C6 20 28 C5 4E 44 20 CF 46 20 C6 |AN ... (.ND .F .|
0000C0D0: 49 4C 45 29 20 50 41 43 4B 45 54 20 41 52 52 49 |ILE) PACKET ARRI|
0000C0E0: 56 45 53 2E 20 20 C1 54 20 54 48 41 54 20 50 4F |VES. .T THAT PO|
0000C0F0: 49 4E 54 0D CB C5 D2 CD C9 D4 20 53 57 49 54 43 |INT....... SWITC|
0000C100: 48 45 53 20 42 41 43 4B 20 54 4F 20 D2 45 43 45 |HES BACK TO .ECE|
0000C110: 49 56 45 20 C6 49 4C 45 20 53 54 41 54 45 2E 20 |IVE .ILE STATE. |
0000C120: 20 C9 46 20 41 4E 4F 54 48 45 52 20 46 49 4C 45 | .F ANOTHER FILE|
0000C130: 20 49 53 20 54 4F 20 42 45 20 53 45 4E 54 2C 0D | IS TO BE SENT,.|
0000C140: 41 4E 4F 54 48 45 52 20 C6 49 4C 45 20 C8 45 41 |ANOTHER .ILE .EA|
0000C150: 44 45 52 20 50 41 43 4B 45 54 20 57 49 4C 4C 20 |DER PACKET WILL |
0000C160: 46 4F 4C 4C 4F 57 2C 20 4F 54 48 45 52 57 49 53 |FOLLOW, OTHERWIS|
0000C170: 45 20 41 4E 20 C5 CF D4 20 28 C5 4E 44 20 CF 46 |E AN ... (.ND .F|
0000C180: 20 D4 52 41 4E 53 4D 49 53 53 49 4F 4E 29 0D 50 | .RANSMISSION).P|
0000C190: 41 43 4B 45 54 20 57 49 4C 4C 20 54 45 52 4D 49 |ACKET WILL TERMI|
0000C1A0: 4E 41 54 45 20 54 48 45 20 54 52 41 4E 53 46 45 |NATE THE TRANSFE|
0000C1B0: 52 2E 20 20 D4 48 45 20 44 49 53 54 49 4E 43 54 |R. .HE DISTINCT|
0000C1C0: 49 4F 4E 20 42 45 54 57 45 45 4E 20 C5 CF C6 20 |ION BETWEEN ... |
0000C1D0: 41 4E 44 20 C5 CF D4 2C 20 50 4C 55 53 0D 54 48 |AND ..., PLUS.TH|
0000C1E0: 45 20 C6 49 4C 45 20 C8 45 41 44 45 52 20 49 54 |E .ILE .EADER IT|
0000C1F0: 53 45 4C 46 2C 20 41 4C 4C 4F 57 53 20 46 49 4C |SELF, ALLOWS FIL|
0000C200: 45 53 20 54 4F 20 42 45 20 53 45 4E 54 20 49 4E |ES TO BE SENT IN|
0000C210: 20 47 52 4F 55 50 53 2E 20 20 C5 CF C6 20 4D 41 | GROUPS. ... MA|
0000C220: 52 4B 53 20 54 48 45 20 45 4E 44 0D 4F 46 20 41 |RKS THE END.OF A|
0000C230: 20 46 49 4C 45 2C 20 C5 CF D4 20 4D 41 52 4B 53 | FILE, ... MARKS|
0000C240: 20 54 48 45 20 45 4E 44 20 4F 46 20 41 20 47 52 | THE END OF A GR|
0000C250: 4F 55 50 2E 20 D4 48 49 53 20 44 49 53 54 49 4E |OUP. .HIS DISTIN|
0000C260: 43 54 49 4F 4E 20 41 4C 53 4F 20 41 4C 4C 4F 57 |CTION ALSO ALLOW|
0000C270: 53 20 54 48 45 20 54 57 4F 0D 53 49 44 45 53 20 |S THE TWO.SIDES |
0000C280: 54 4F 20 44 49 53 43 4F 4E 4E 45 43 54 20 43 4C |TO DISCONNECT CL|
0000C290: 45 41 4E 4C 59 3A 20 54 48 45 20 C5 CF C6 20 4D |EANLY: THE ... M|
0000C2A0: 55 53 54 20 42 45 20 C1 C3 CB 27 44 20 42 45 46 |UST BE ...'D BEF|
0000C2B0: 4F 52 45 20 54 48 45 20 53 45 4E 44 45 52 20 57 |ORE THE SENDER W|
0000C2C0: 49 4C 4C 0D 42 45 4C 49 45 56 45 20 54 48 45 20 |ILL.BELIEVE THE |
0000C2D0: 46 49 4C 45 20 48 41 53 20 42 45 45 4E 20 54 52 |FILE HAS BEEN TR|
0000C2E0: 41 4E 53 4D 49 54 54 45 44 20 43 4F 52 52 45 43 |ANSMITTED CORREC|
0000C2F0: 54 4C 59 3B 20 54 48 45 20 C5 CF D4 20 57 49 4C |TLY; THE ... WIL|
0000C300: 4C 20 46 4F 4C 4C 4F 57 2C 20 42 55 54 20 49 46 |L FOLLOW, BUT IF|
0000C310: 0D 54 48 45 20 C1 C3 CB 20 57 48 49 43 48 20 49 |.THE ... WHICH I|
0000C320: 53 20 53 45 4E 54 20 49 4E 20 52 45 53 50 4F 4E |S SENT IN RESPON|
0000C330: 53 45 20 49 53 20 4C 4F 53 54 2C 20 4E 4F 20 48 |SE IS LOST, NO H|
0000C340: 41 52 4D 20 57 49 4C 4C 20 42 45 20 44 4F 4E 45 |ARM WILL BE DONE|
0000C350: 20 53 49 4E 43 45 20 42 4F 54 48 0D 53 49 44 45 | SINCE BOTH.SIDE|
0000C360: 53 20 41 52 45 20 54 45 52 4D 49 4E 41 54 49 4E |S ARE TERMINATIN|
0000C370: 47 20 41 4E 59 57 41 59 2E 20 D4 48 45 20 53 54 |G ANYWAY. .HE ST|
0000C380: 41 54 45 20 54 52 41 4E 53 49 54 49 4F 4E 53 20 |ATE TRANSITIONS |
0000C390: 46 4F 52 20 41 20 53 45 4E 44 49 4E 47 20 CB C5 |FOR A SENDING ..|
0000C3A0: D2 CD C9 D4 20 41 52 45 0D 53 49 4D 49 4C 41 52 |.... ARE.SIMILAR|
0000C3B0: 2E 20 C9 4E 20 45 41 43 48 20 53 54 41 54 45 2C |. .N EACH STATE,|
0000C3C0: 20 49 4E 53 54 45 41 44 20 4F 46 20 57 41 49 54 | INSTEAD OF WAIT|
0000C3D0: 49 4E 47 20 46 4F 52 20 50 41 52 54 49 43 55 4C |ING FOR PARTICUL|
0000C3E0: 41 52 20 50 41 43 4B 45 54 20 54 59 50 45 53 2C |AR PACKET TYPES,|
0000C3F0: 20 CB C5 D2 CD C9 D4 0D 53 45 4E 44 53 20 54 48 | .......SENDS TH|
0000C400: 45 20 41 50 50 52 4F 50 52 49 41 54 45 20 50 41 |E APPROPRIATE PA|
0000C410: 43 4B 45 54 20 41 4E 44 20 57 41 49 54 53 20 46 |CKET AND WAITS F|
0000C420: 4F 52 20 41 4E 20 C1 C3 CB 2E 20 20 C9 46 20 54 |OR AN .... .F T|
0000C430: 48 45 20 C1 C3 CB 20 44 4F 45 53 20 4E 4F 54 20 |HE ... DOES NOT |
0000C440: 41 52 52 49 56 45 0D 57 49 54 48 49 4E 20 54 48 |ARRIVE.WITHIN TH|
0000C450: 45 20 41 4C 4C 4F 54 54 45 44 20 54 49 4D 45 2C |E ALLOTTED TIME,|
0000C460: 20 4F 52 20 41 20 CE C1 CB 20 41 50 50 45 41 52 | OR A ... APPEAR|
0000C470: 53 20 49 4E 53 54 45 41 44 20 4F 46 20 41 4E 20 |S INSTEAD OF AN |
0000C480: C1 C3 CB 2C 20 54 48 45 20 53 41 4D 45 20 50 41 |..., THE SAME PA|
0000C490: 43 4B 45 54 0D 49 53 20 52 45 54 52 41 4E 53 4D |CKET.IS RETRANSM|
0000C4A0: 49 54 54 45 44 2E 20 20 C1 20 53 45 4E 44 20 4F |ITTED. . SEND O|
0000C4B0: 50 45 52 41 54 49 4F 4E 20 42 45 47 49 4E 53 20 |PERATION BEGINS |
0000C4C0: 57 49 54 48 20 41 20 D3 45 4E 44 2D C9 4E 49 54 |WITH A .END-.NIT|
0000C4D0: 20 50 41 43 4B 45 54 2C 20 49 4E 43 4C 55 44 45 | PACKET, INCLUDE|
0000C4E0: 53 0D 4F 4E 45 20 4F 52 20 4D 4F 52 45 20 46 49 |S.ONE OR MORE FI|
0000C4F0: 4C 45 53 2C 20 45 41 43 48 20 53 54 41 52 54 49 |LES, EACH STARTI|
0000C500: 4E 47 20 57 49 54 48 20 41 20 C6 49 4C 45 20 C8 |NG WITH A .ILE .|
0000C510: 45 41 44 45 52 2C 20 46 4F 4C 4C 4F 57 45 44 20 |EADER, FOLLOWED |
0000C520: 42 59 20 4F 4E 45 20 4F 52 20 4D 4F 52 45 0D 44 |BY ONE OR MORE.D|
0000C530: 41 54 41 20 50 41 43 4B 45 54 53 2C 20 46 4F 4C |ATA PACKETS, FOL|
0000C540: 4C 4F 57 45 44 20 42 59 20 C5 CF C6 2E 20 20 D7 |LOWED BY .... .|
0000C550: 48 45 4E 20 41 4C 4C 20 54 48 45 20 53 50 45 43 |HEN ALL THE SPEC|
0000C560: 49 46 49 45 44 20 46 49 4C 45 53 20 48 41 56 45 |IFIED FILES HAVE|
0000C570: 20 42 45 45 4E 20 53 45 4E 54 2C 20 41 4E 0D C5 | BEEN SENT, AN..|
0000C580: CF D4 20 50 41 43 4B 45 54 20 43 4C 4F 53 45 53 |.. PACKET CLOSES|
0000C590: 20 54 48 45 20 43 4F 4E 4E 45 43 54 49 4F 4E 20 | THE CONNECTION |
0000C5A0: 41 4E 44 20 54 45 52 4D 49 4E 41 54 45 53 20 54 |AND TERMINATES T|
0000C5B0: 48 45 20 4F 50 45 52 41 54 49 4F 4E 2E 0D 0D 20 |HE OPERATION... |
0000C5C0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C5D0: 20 20 20 20 20 20 20 20 20 20 20 2B 2D 2D 2D 2D | +----|
0000C5E0: 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 20 20 20 20 20 |-------+. |
0000C5F0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C600: 20 20 20 20 20 21 20 D3 45 4E 44 20 C9 4E 49 54 | ! .END .NIT|
0000C610: 20 21 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 | !. |
0000C620: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 2B | +|
0000C630: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 20 |-----------+. |
0000C640: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C650: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C660: 20 21 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 | !. |
0000C670: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C680: 20 20 20 20 20 20 20 21 20 28 C7 45 54 20 C7 4F | ! (.ET .O|
0000C690: 4F 44 20 C1 C3 CB 29 0D 20 20 20 20 20 20 20 20 |OD ...). |
0000C6A0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C6B0: 20 20 20 20 20 20 20 20 20 20 20 20 21 0D 20 20 | !. |
0000C6C0: 20 28 CE 4F 20 4D 4F 52 45 20 46 49 4C 45 53 20 | (.O MORE FILES |
0000C6D0: 54 4F 20 53 45 4E 44 29 20 20 20 20 20 20 20 20 |TO SEND) |
0000C6E0: 20 20 D6 0D 20 20 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D | .. +---------|
0000C6F0: 2D 2B 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |-+ |
0000C700: 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 |+-----------+. |
0000C710: 21 20 D3 45 4E 44 20 C5 CF D4 20 21 3C 2D 2D 2D |! .END ... !<---|
0000C720: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 21 20 D3 45 4E 44 |----------! .END|
0000C730: 20 C6 49 4C 45 20 21 3C 2D 2D 2D 2D 2D 2D 2D 2D | .ILE !<--------|
0000C740: 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 2B 2D 2D 2D 2D |-------+. +----|
0000C750: 2D 2D 2D 2D 2D 2D 2B 20 20 20 20 20 20 20 20 20 |------+ |
0000C760: 20 20 20 20 20 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D | +----------|
0000C770: 2D 2B 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |-+ |
0000C780: 20 20 21 0D 20 20 20 20 20 20 20 20 20 20 20 20 | !. |
0000C790: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C7A0: 20 20 20 20 20 20 20 20 21 20 20 20 20 20 20 20 | ! |
0000C7B0: 20 20 20 20 20 20 20 20 20 20 20 20 20 21 0D 20 | !. |
0000C7C0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C7D0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C7E0: 20 20 20 21 20 28 C7 4F 4F 44 20 C1 C3 CB 29 20 | ! (.OOD ...) |
0000C7F0: 20 20 20 20 20 20 20 20 21 20 28 C5 CF C6 29 0D | ! (...).|
0000C800: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C810: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C820: 20 20 20 20 21 20 20 20 20 20 20 20 20 20 20 20 | ! |
0000C830: 20 20 20 20 20 20 20 20 20 21 0D 20 20 20 20 20 | !. |
0000C840: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C850: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 D6 | .|
0000C860: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C870: 20 20 20 20 21 0D 20 20 20 20 20 20 20 20 20 20 | !. |
0000C880: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C890: 20 20 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 20 | +-----------+ |
0000C8A0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 | !|
0000C8B0: 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |. |
0000C8C0: 20 20 20 20 20 2B 2D 2D 2D 2D 2D 2D 3E 21 20 D3 | +------>! .|
0000C8D0: 45 4E 44 20 C4 41 54 41 20 21 2D 2D 2D 2D 2D 2D |END .ATA !------|
0000C8E0: 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2B 0D 20 20 20 20 |----------+. |
0000C8F0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C900: 21 20 20 20 20 20 20 20 2B 2D 2D 2D 2D 2D 2D 2D |! +-------|
0000C910: 2D 2D 2D 2D 2B 0D 20 20 20 20 20 20 20 20 20 20 |----+. |
0000C920: 20 20 20 20 20 20 20 20 20 20 21 20 20 20 20 20 | ! |
0000C930: 20 20 20 20 20 20 20 20 20 20 21 0D 20 20 20 20 | !. |
0000C940: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C950: 21 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |! |
0000C960: 21 20 28 C7 4F 4F 44 20 C1 C3 CB 29 0D 20 20 20 |! (.OOD ...). |
0000C970: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000C980: 20 21 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | ! |
0000C990: 20 21 0D 20 20 20 20 20 20 20 20 20 20 20 20 20 | !. |
0000C9A0: 20 20 20 20 20 20 20 2B 2D 2D 2D 2D 2D 2D 2D 2D | +--------|
0000C9B0: 2D 2D 2D 2D 2D 2D 2D 2B 0D 0D 0D C2 41 53 45 2D |-------+....ASE-|
0000C9C0: 4C 45 56 45 4C 20 CB C5 D2 CD C9 D4 20 50 52 4F |LEVEL ...... PRO|
0000C9D0: 56 49 44 45 53 20 54 48 41 54 20 44 55 52 49 4E |VIDES THAT DURIN|
0000C9E0: 47 20 41 4E 59 20 50 41 52 54 49 43 55 4C 41 52 |G ANY PARTICULAR|
0000C9F0: 20 54 52 41 4E 53 41 43 54 49 4F 4E 2C 20 54 48 | TRANSACTION, TH|
0000CA00: 45 20 53 45 4E 44 45 52 0D 49 53 20 54 48 45 20 |E SENDER.IS THE |
0000CA10: 22 4D 41 53 54 45 52 22 20 41 4E 44 20 54 48 45 |"MASTER" AND THE|
0000CA20: 20 52 45 43 45 49 56 45 52 20 49 53 20 54 48 45 | RECEIVER IS THE|
0000CA30: 20 22 53 4C 41 56 45 22 2E 20 20 D4 48 45 53 45 | "SLAVE". .HESE|
0000CA40: 20 52 4F 4C 45 53 20 4D 41 59 20 42 45 20 52 45 | ROLES MAY BE RE|
0000CA50: 56 45 52 53 45 44 0D 49 4E 20 54 48 45 20 4E 45 |VERSED.IN THE NE|
0000CA60: 58 54 20 54 52 41 4E 53 41 43 54 49 4F 4E 3B 20 |XT TRANSACTION; |
0000CA70: 41 4E 59 20 CB C5 D2 CD C9 D4 20 49 4D 50 4C 45 |ANY ...... IMPLE|
0000CA80: 4D 45 4E 54 41 54 49 4F 4E 20 49 53 20 43 41 50 |MENTATION IS CAP|
0000CA90: 41 42 4C 45 20 4F 46 20 41 43 54 49 4E 47 20 41 |ABLE OF ACTING A|
0000CAA0: 53 0D 45 49 54 48 45 52 20 4D 41 53 54 45 52 20 |S.EITHER MASTER |
0000CAB0: 4F 52 20 53 4C 41 56 45 2E 20 20 C9 4E 20 41 44 |OR SLAVE. .N AD|
0000CAC0: 44 49 54 49 4F 4E 2C 20 4D 41 49 4E 46 52 41 4D |DITION, MAINFRAM|
0000CAD0: 45 20 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E |E IMPLEMENTATION|
0000CAE0: 53 20 4D 41 59 20 41 4C 53 4F 20 42 45 20 50 55 |S MAY ALSO BE PU|
0000CAF0: 54 0D 49 4E 20 41 20 4B 49 4E 44 20 4F 46 20 50 |T.IN A KIND OF P|
0000CB00: 45 52 4D 41 4E 45 4E 54 20 53 4C 41 56 45 2C 20 |ERMANENT SLAVE, |
0000CB10: 4F 52 20 22 53 45 52 56 45 52 22 2C 20 4D 4F 44 |OR "SERVER", MOD|
0000CB20: 45 20 49 4E 20 57 48 49 43 48 20 41 4C 4C 20 43 |E IN WHICH ALL C|
0000CB30: 4F 4D 4D 41 4E 44 53 20 43 4F 4D 45 20 49 4E 0D |OMMANDS COME IN.|
0000CB40: 43 4F 4D 4D 41 4E 44 20 50 41 43 4B 45 54 53 20 |COMMAND PACKETS |
0000CB50: 46 52 4F 4D 20 54 48 45 20 4D 41 53 54 45 52 2C |FROM THE MASTER,|
0000CB60: 20 4F 52 20 22 55 53 45 52 22 20 CB C5 D2 CD C9 | OR "USER" .....|
0000CB70: D4 2E 0D C9 4E 49 54 49 41 4C 20 C3 4F 4E 4E 45 |....NITIAL .ONNE|
0000CB80: 43 54 49 4F 4E 0D 0D D4 4F 20 41 4C 4C 4F 57 20 |CTION...O ALLOW |
0000CB90: 41 20 44 49 56 45 52 53 45 20 47 52 4F 55 50 20 |A DIVERSE GROUP |
0000CBA0: 4F 46 20 43 4F 4D 50 55 54 45 52 53 20 54 4F 20 |OF COMPUTERS TO |
0000CBB0: 43 4F 4D 4D 55 4E 49 43 41 54 45 20 57 49 54 48 |COMMUNICATE WITH|
0000CBC0: 20 4F 4E 45 20 41 4E 4F 54 48 45 52 2C 20 41 4E | ONE ANOTHER, AN|
0000CBD0: 0D 45 58 43 48 41 4E 47 45 20 54 41 4B 45 53 20 |.EXCHANGE TAKES |
0000CBE0: 50 4C 41 43 45 53 20 44 55 52 49 4E 47 20 49 4E |PLACES DURING IN|
0000CBF0: 49 54 49 41 4C 20 43 4F 4E 4E 45 43 54 49 4F 4E |ITIAL CONNECTION|
0000CC00: 20 49 4E 20 57 48 49 43 48 20 54 48 45 20 54 57 | IN WHICH THE TW|
0000CC10: 4F 20 53 49 44 45 53 0D 22 43 4F 4E 46 49 47 55 |O SIDES."CONFIGU|
0000CC20: 52 45 22 20 45 41 43 48 20 4F 54 48 45 52 2E 20 |RE" EACH OTHER. |
0000CC30: 20 D4 48 45 20 53 45 4E 44 49 4E 47 20 CB C5 D2 | .HE SENDING ...|
0000CC40: CD C9 D4 20 49 4E 43 4C 55 44 45 53 20 53 45 54 |... INCLUDES SET|
0000CC50: 55 50 20 50 41 52 41 4D 45 54 45 52 53 20 49 4E |UP PARAMETERS IN|
0000CC60: 0D 49 54 53 20 D3 45 4E 44 2D C9 4E 49 54 20 50 |.ITS .END-.NIT P|
0000CC70: 41 43 4B 45 54 20 41 4E 44 20 54 48 45 20 52 45 |ACKET AND THE RE|
0000CC80: 43 45 49 56 49 4E 47 20 CB C5 D2 CD C9 D4 20 52 |CEIVING ...... R|
0000CC90: 45 53 50 4F 4E 44 53 20 57 49 54 48 20 41 4E 20 |ESPONDS WITH AN |
0000CCA0: C1 C3 CB 20 50 41 43 4B 45 54 0D 43 4F 4E 54 41 |... PACKET.CONTA|
0000CCB0: 49 4E 49 4E 47 20 54 48 45 20 43 4F 52 52 45 53 |INING THE CORRES|
0000CCC0: 50 4F 4E 44 49 4E 47 20 50 41 52 41 4D 45 54 45 |PONDING PARAMETE|
0000CCD0: 52 53 20 41 53 20 54 48 45 59 20 41 50 50 4C 59 |RS AS THEY APPLY|
0000CCE0: 20 54 4F 20 49 54 53 45 4C 46 2E 20 20 D4 48 45 | TO ITSELF. .HE|
0000CCF0: 20 C4 41 54 41 0D 46 49 45 4C 44 20 4F 46 20 54 | .ATA.FIELD OF T|
0000CD00: 48 45 20 D3 45 4E 44 2D C9 4E 49 54 20 50 41 43 |HE .END-.NIT PAC|
0000CD10: 4B 45 54 20 4C 4F 4F 4B 53 20 4C 49 4B 45 20 54 |KET LOOKS LIKE T|
0000CD20: 48 49 53 3A 0D 0D 31 20 20 20 20 20 20 32 20 20 |HIS:..1 2 |
0000CD30: 20 20 20 20 33 20 20 20 20 20 20 34 20 20 20 20 | 3 4 |
0000CD40: 20 20 35 20 20 20 20 20 20 36 20 20 20 20 20 20 | 5 6 |
0000CD50: 37 20 20 20 20 20 20 38 20 20 20 20 20 20 39 20 |7 8 9 |
0000CD60: 20 20 20 20 20 31 30 0D 2B 2D 2D 2D 2D 2D 2D 2B | 10.+------+|
0000CD70: 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D |------+------+--|
0000CD80: 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D |----+------+----|
0000CD90: 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D |--+------+------|
0000CDA0: 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2D 2D |+------+--------|
0000CDB0: 2D 2D 2D 2D 2D 0D 21 20 CD C1 D8 CC 20 21 20 D4 |-----.! .... ! .|
0000CDC0: C9 CD C5 20 21 20 CE D0 C1 C4 20 21 20 D0 C1 C4 |... ! .... ! ...|
0000CDD0: C3 20 21 20 C5 CF CC 20 20 21 20 D1 C3 D4 CC 20 |. ! ... ! .... |
0000CDE0: 21 20 D1 C2 C9 CE 20 21 20 C3 C8 CB D4 20 21 20 |! .... ! .... ! |
0000CDF0: D2 C5 D0 D4 20 21 20 20 C3 C1 D0 C1 D3 2E 2E 2E |.... ! ........|
0000CE00: 0D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B |.+------+------+|
0000CE10: 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D |------+------+--|
0000CE20: 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D |----+------+----|
0000CE30: 2D 2D 2B 2D 2D 2D 2D 2D 2D 2B 2D 2D 2D 2D 2D 2D |--+------+------|
0000CE40: 2B 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 2D 0D 0D |+-------------..|
0000CE50: D4 48 45 20 46 49 45 4C 44 53 20 41 52 45 20 41 |.HE FIELDS ARE A|
0000CE60: 53 20 46 4F 4C 4C 4F 57 53 20 28 54 48 45 20 46 |S FOLLOWS (THE F|
0000CE70: 49 52 53 54 20 41 4E 44 20 53 45 43 4F 4E 44 20 |IRST AND SECOND |
0000CE80: 50 45 52 53 4F 4E 20 22 C9 22 20 41 4E 44 20 22 |PERSON "." AND "|
0000CE90: 59 4F 55 22 20 41 52 45 20 55 53 45 44 0D 54 4F |YOU" ARE USED.TO|
0000CEA0: 20 44 49 53 54 49 4E 47 55 49 53 48 20 54 48 45 | DISTINGUISH THE|
0000CEB0: 20 54 57 4F 20 53 49 44 45 53 29 2E 20 20 C6 49 | TWO SIDES). .I|
0000CEC0: 45 4C 44 53 20 41 52 45 20 45 4E 43 4F 44 45 44 |ELDS ARE ENCODED|
0000CED0: 20 50 52 49 4E 54 41 42 4C 59 20 55 53 49 4E 47 | PRINTABLY USING|
0000CEE0: 20 54 48 45 20 43 48 41 52 0D 46 55 4E 43 54 49 | THE CHAR.FUNCTI|
0000CEF0: 4F 4E 20 28 C1 D3 C3 C9 C9 20 56 41 4C 55 45 20 |ON (..... VALUE |
0000CF00: 2B 20 33 32 29 20 55 4E 4C 45 53 53 20 49 4E 44 |+ 32) UNLESS IND|
0000CF10: 49 43 41 54 45 44 20 4F 54 48 45 52 57 49 53 45 |ICATED OTHERWISE|
0000CF20: 2E 0D 0D CD C1 D8 CC 20 20 D4 48 45 20 4D 41 58 |....... .HE MAX|
0000CF30: 49 4D 55 4D 20 4C 45 4E 47 54 48 20 50 41 43 4B |IMUM LENGTH PACK|
0000CF40: 45 54 20 C9 20 57 41 4E 54 20 54 4F 20 52 45 43 |ET . WANT TO REC|
0000CF50: 45 49 56 45 2C 20 41 20 4E 55 4D 42 45 52 20 55 |EIVE, A NUMBER U|
0000CF60: 50 20 54 4F 20 39 34 2E 20 D9 4F 55 0D 52 45 53 |P TO 94. .OU.RES|
0000CF70: 50 4F 4E 44 20 57 49 54 48 20 54 48 45 20 4D 41 |POND WITH THE MA|
0000CF80: 58 49 4D 55 4D 20 59 4F 55 20 57 41 4E 54 20 4D |XIMUM YOU WANT M|
0000CF90: 45 20 54 4F 20 53 45 4E 44 2E 20 D4 48 49 53 20 |E TO SEND. .HIS |
0000CFA0: 41 4C 4C 4F 57 53 20 53 59 53 54 45 4D 53 20 54 |ALLOWS SYSTEMS T|
0000CFB0: 4F 20 41 44 4A 55 53 54 20 54 4F 0D 45 41 43 48 |O ADJUST TO.EACH|
0000CFC0: 20 4F 54 48 45 52 27 53 20 42 55 46 46 45 52 20 | OTHER'S BUFFER |
0000CFD0: 53 49 5A 45 53 2C 20 4F 52 20 54 4F 20 54 48 45 |SIZES, OR TO THE|
0000CFE0: 20 43 4F 4E 44 49 54 49 4F 4E 20 4F 46 20 54 48 | CONDITION OF TH|
0000CFF0: 45 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E 20 4D |E TRANSMISSION M|
0000D000: 45 44 49 55 4D 2E 0D 0D D4 C9 CD C5 20 20 D4 48 |EDIUM....... .H|
0000D010: 45 20 4E 55 4D 42 45 52 20 4F 46 20 53 45 43 4F |E NUMBER OF SECO|
0000D020: 4E 44 53 20 41 46 54 45 52 20 57 48 49 43 48 20 |NDS AFTER WHICH |
0000D030: C9 20 57 41 4E 54 20 59 4F 55 20 54 4F 20 54 49 |. WANT YOU TO TI|
0000D040: 4D 45 20 4D 45 20 4F 55 54 20 57 48 49 4C 45 20 |ME ME OUT WHILE |
0000D050: 57 41 49 54 49 4E 47 0D 46 4F 52 20 41 20 50 41 |WAITING.FOR A PA|
0000D060: 43 4B 45 54 20 46 52 4F 4D 20 4D 45 2E 20 20 D9 |CKET FROM ME. .|
0000D070: 4F 55 20 52 45 53 50 4F 4E 44 20 57 49 54 48 20 |OU RESPOND WITH |
0000D080: 54 48 45 20 41 4D 4F 55 4E 54 20 4F 46 20 54 49 |THE AMOUNT OF TI|
0000D090: 4D 45 20 C9 20 53 48 4F 55 4C 44 20 57 41 49 54 |ME . SHOULD WAIT|
0000D0A0: 20 46 4F 52 0D 50 41 43 4B 45 54 53 20 46 52 4F | FOR.PACKETS FRO|
0000D0B0: 4D 20 59 4F 55 2E 20 20 D4 48 49 53 20 41 4C 4C |M YOU. .HIS ALL|
0000D0C0: 4F 57 53 20 54 48 45 20 54 57 4F 20 53 49 44 45 |OWS THE TWO SIDE|
0000D0D0: 53 20 54 4F 20 41 43 43 4F 4D 4D 4F 44 41 54 45 |S TO ACCOMMODATE|
0000D0E0: 20 54 4F 20 44 49 46 46 45 52 45 4E 54 20 4C 49 | TO DIFFERENT LI|
0000D0F0: 4E 45 0D 53 50 45 45 44 53 20 4F 52 20 4F 54 48 |NE.SPEEDS OR OTH|
0000D100: 45 52 20 46 41 43 54 4F 52 53 20 54 48 41 54 20 |ER FACTORS THAT |
0000D110: 43 4F 55 4C 44 20 43 41 55 53 45 20 54 49 4D 49 |COULD CAUSE TIMI|
0000D120: 4E 47 20 50 52 4F 42 4C 45 4D 53 2E 0D 0D CE D0 |NG PROBLEMS.....|
0000D130: C1 C4 20 20 D4 48 45 20 4E 55 4D 42 45 52 20 4F |.. .HE NUMBER O|
0000D140: 46 20 50 41 44 44 49 4E 47 20 43 48 41 52 41 43 |F PADDING CHARAC|
0000D150: 54 45 52 53 20 C9 20 57 41 4E 54 20 54 4F 20 50 |TERS . WANT TO P|
0000D160: 52 45 43 45 44 45 20 45 41 43 48 20 49 4E 43 4F |RECEDE EACH INCO|
0000D170: 4D 49 4E 47 20 50 41 43 4B 45 54 3B 0D 59 4F 55 |MING PACKET;.YOU|
0000D180: 20 52 45 53 50 4F 4E 44 20 49 4E 20 4B 49 4E 44 | RESPOND IN KIND|
0000D190: 2E 20 20 D0 41 44 44 49 4E 47 20 4D 41 59 20 42 |. .ADDING MAY B|
0000D1A0: 45 20 4E 45 43 45 53 53 41 52 59 20 46 4F 52 20 |E NECESSARY FOR |
0000D1B0: 41 20 48 41 4C 46 20 44 55 50 4C 45 58 20 53 59 |A HALF DUPLEX SY|
0000D1C0: 53 54 45 4D 20 54 48 41 54 0D 52 45 51 55 49 52 |STEM THAT.REQUIR|
0000D1D0: 45 53 20 53 4F 4D 45 20 54 49 4D 45 20 54 4F 20 |ES SOME TIME TO |
0000D1E0: 43 48 41 4E 47 45 20 54 48 45 20 44 49 52 45 43 |CHANGE THE DIREC|
0000D1F0: 54 49 4F 4E 20 4F 46 20 54 52 41 4E 53 4D 49 53 |TION OF TRANSMIS|
0000D200: 53 49 4F 4E 2E 0D 0D D0 C1 C4 C3 20 20 D4 48 45 |SION....... .HE|
0000D210: 20 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 43 54 | CONTROL CHARACT|
0000D220: 45 52 20 C9 20 4E 45 45 44 20 46 4F 52 20 50 41 |ER . NEED FOR PA|
0000D230: 44 44 49 4E 47 2C 20 49 46 20 41 4E 59 2C 20 D8 |DDING, IF ANY, .|
0000D240: CF D2 27 44 20 57 49 54 48 20 31 30 30 20 4F 43 |..'D WITH 100 OC|
0000D250: 54 41 4C 0D 54 4F 20 4D 41 4B 45 20 49 54 20 50 |TAL.TO MAKE IT P|
0000D260: 52 49 4E 54 41 42 4C 45 2E 20 20 D9 4F 55 20 52 |RINTABLE. .OU R|
0000D270: 45 53 50 4F 4E 44 20 49 4E 20 4B 49 4E 44 2E 20 |ESPOND IN KIND. |
0000D280: 20 CE 4F 52 4D 41 4C 4C 59 20 CE D5 CC 20 28 C1 | .ORMALLY ... (.|
0000D290: D3 C3 C9 C9 20 30 29 2C 20 53 4F 4D 45 0D 53 59 |.... 0), SOME.SY|
0000D2A0: 53 54 45 4D 53 20 55 53 45 20 C4 C5 CC 20 28 C1 |STEMS USE ... (.|
0000D2B0: D3 C3 C9 C9 20 31 37 37 29 2E 20 20 D4 48 49 53 |.... 177). .HIS|
0000D2C0: 20 46 49 45 4C 44 20 49 53 20 49 47 4E 4F 52 45 | FIELD IS IGNORE|
0000D2D0: 44 20 49 46 20 54 48 45 20 56 41 4C 55 45 20 CE |D IF THE VALUE .|
0000D2E0: D0 C1 C4 20 49 53 20 5A 45 52 4F 2E 0D 0D C5 CF |... IS ZERO.....|
0000D2F0: CC 20 20 D4 48 45 20 43 48 41 52 41 43 54 45 52 |. .HE CHARACTER|
0000D300: 20 C9 20 4E 45 45 44 20 54 4F 20 54 45 52 4D 49 | . NEED TO TERMI|
0000D310: 4E 41 54 45 20 41 4E 20 49 4E 43 4F 4D 49 4E 47 |NATE AN INCOMING|
0000D320: 20 50 41 43 4B 45 54 2C 20 49 46 20 41 4E 59 2E | PACKET, IF ANY.|
0000D330: 20 D9 4F 55 20 52 45 53 50 4F 4E 44 0D 49 4E 20 | .OU RESPOND.IN |
0000D340: 4B 49 4E 44 2E 20 20 CD 4F 53 54 20 53 59 53 54 |KIND. .OST SYST|
0000D350: 45 4D 53 20 54 48 41 54 20 52 45 51 55 49 52 45 |EMS THAT REQUIRE|
0000D360: 20 41 20 4C 49 4E 45 20 54 45 52 4D 49 4E 41 54 | A LINE TERMINAT|
0000D370: 4F 52 20 46 4F 52 20 54 45 52 4D 49 4E 41 4C 20 |OR FOR TERMINAL |
0000D380: 49 4E 50 55 54 20 41 43 43 45 50 54 0D 43 41 52 |INPUT ACCEPT.CAR|
0000D390: 52 49 41 47 45 20 52 45 54 55 52 4E 20 46 4F 52 |RIAGE RETURN FOR|
0000D3A0: 20 54 48 49 53 20 50 55 52 50 4F 53 45 2E 20 20 | THIS PURPOSE. |
0000D3B0: 28 C3 41 4E 20 59 4F 55 20 53 45 45 20 54 48 45 |(.AN YOU SEE THE|
0000D3C0: 20 C3 41 54 43 48 2D 32 32 20 48 45 52 45 3F 29 | .ATCH-22 HERE?)|
0000D3D0: 0D 0D D1 C3 D4 CC 20 20 D4 48 45 20 50 52 49 4E |...... .HE PRIN|
0000D3E0: 54 41 42 4C 45 20 C1 D3 C3 C9 C9 20 43 48 41 52 |TABLE ..... CHAR|
0000D3F0: 41 43 54 45 52 20 C9 20 57 49 4C 4C 20 55 53 45 |ACTER . WILL USE|
0000D400: 20 54 4F 20 51 55 4F 54 45 20 43 4F 4E 54 52 4F | TO QUOTE CONTRO|
0000D410: 4C 20 43 48 41 52 41 43 54 45 52 53 20 41 4E 44 |L CHARACTERS AND|
0000D420: 0D 50 52 45 46 49 58 20 43 48 41 52 41 43 54 45 |.PREFIX CHARACTE|
0000D430: 52 53 2C 20 4E 4F 52 4D 41 4C 4C 59 20 22 23 22 |RS, NORMALLY "#"|
0000D440: 2E 20 D9 4F 55 20 52 45 53 50 4F 4E 44 20 57 49 |. .OU RESPOND WI|
0000D450: 54 48 20 54 48 45 20 4F 4E 45 20 59 4F 55 20 57 |TH THE ONE YOU W|
0000D460: 49 4C 4C 20 55 53 45 2E 0D 0D D1 C2 C9 CE 20 20 |ILL USE....... |
0000D470: D4 48 45 20 50 52 49 4E 54 41 42 4C 45 20 C1 D3 |.HE PRINTABLE ..|
0000D480: C3 C9 C9 20 43 48 41 52 41 43 54 45 52 20 C9 20 |... CHARACTER . |
0000D490: 57 41 4E 54 20 54 4F 20 55 53 45 20 54 4F 20 51 |WANT TO USE TO Q|
0000D4A0: 55 4F 54 45 20 43 48 41 52 41 43 54 45 52 53 20 |UOTE CHARACTERS |
0000D4B0: 57 48 49 43 48 0D 48 41 56 45 20 54 48 45 20 38 |WHICH.HAVE THE 8|
0000D4C0: 54 48 20 42 49 54 20 53 45 54 2C 20 46 4F 52 20 |TH BIT SET, FOR |
0000D4D0: 54 52 41 4E 53 4D 49 54 54 49 4E 47 20 42 49 4E |TRANSMITTING BIN|
0000D4E0: 41 52 59 20 46 49 4C 45 53 20 57 48 45 4E 20 4F |ARY FILES WHEN O|
0000D4F0: 4E 45 20 4F 52 20 42 4F 54 48 20 53 59 53 54 45 |NE OR BOTH SYSTE|
0000D500: 4D 53 0D 43 41 4E 4E 4F 54 20 55 53 45 20 54 48 |MS.CANNOT USE TH|
0000D510: 45 20 50 41 52 49 54 59 20 42 49 54 20 46 4F 52 |E PARITY BIT FOR|
0000D520: 20 44 41 54 41 2E 20 20 D3 49 4E 43 45 20 54 48 | DATA. .INCE TH|
0000D530: 49 53 20 4B 49 4E 44 20 4F 46 20 51 55 4F 54 49 |IS KIND OF QUOTI|
0000D540: 4E 47 20 49 4E 43 52 45 41 53 45 53 20 42 4F 54 |NG INCREASES BOT|
0000D550: 48 0D 50 52 4F 43 45 53 53 4F 52 20 41 4E 44 20 |H.PROCESSOR AND |
0000D560: 54 52 41 4E 53 4D 49 53 53 49 4F 4E 20 4F 56 45 |TRANSMISSION OVE|
0000D570: 52 48 45 41 44 2C 20 49 54 20 49 53 20 4E 4F 52 |RHEAD, IT IS NOR|
0000D580: 4D 41 4C 4C 59 20 54 4F 20 42 45 20 41 56 4F 49 |MALLY TO BE AVOI|
0000D590: 44 45 44 2E 0D 0D C3 C8 CB D4 20 20 C3 48 45 43 |DED....... .HEC|
0000D5A0: 4B 20 D4 59 50 45 2C 20 54 48 45 20 4D 45 54 48 |K .YPE, THE METH|
0000D5B0: 4F 44 20 46 4F 52 20 44 45 54 45 43 54 49 4E 47 |OD FOR DETECTING|
0000D5C0: 20 45 52 52 4F 52 53 2E 20 22 31 22 20 46 4F 52 | ERRORS. "1" FOR|
0000D5D0: 20 53 49 4E 47 4C 45 2D 43 48 41 52 41 43 54 45 | SINGLE-CHARACTE|
0000D5E0: 52 0D 43 48 45 43 4B 53 55 4D 20 28 54 48 45 20 |R.CHECKSUM (THE |
0000D5F0: 4E 4F 52 4D 41 4C 20 4D 45 54 48 4F 44 29 2C 20 |NORMAL METHOD), |
0000D600: 22 32 22 20 46 4F 52 20 54 57 4F 2D 43 48 41 52 |"2" FOR TWO-CHAR|
0000D610: 41 43 54 45 52 20 43 48 45 43 4B 53 55 4D 2C 20 |ACTER CHECKSUM, |
0000D620: 22 33 22 20 46 4F 52 20 54 48 52 45 45 2D 0D 43 |"3" FOR THREE-.C|
0000D630: 48 41 52 41 43 54 45 52 20 C3 D2 C3 2D C3 C3 C9 |HARACTER ...-...|
0000D640: D4 D4 2E 20 20 C9 46 20 59 4F 55 52 20 52 45 53 |... .F YOUR RES|
0000D650: 50 4F 4E 53 45 20 41 47 52 45 45 53 2C 20 54 48 |PONSE AGREES, TH|
0000D660: 45 20 44 45 53 49 47 4E 41 54 45 44 20 4D 45 54 |E DESIGNATED MET|
0000D670: 48 4F 44 20 57 49 4C 4C 20 42 45 0D 55 53 45 44 |HOD WILL BE.USED|
0000D680: 3B 20 4F 54 48 45 52 57 49 53 45 20 54 48 45 20 |; OTHERWISE THE |
0000D690: 53 49 4E 47 4C 45 2D 43 48 41 52 41 43 54 45 52 |SINGLE-CHARACTER|
0000D6A0: 20 43 48 45 43 4B 53 55 4D 20 57 49 4C 4C 20 42 | CHECKSUM WILL B|
0000D6B0: 45 20 55 53 45 44 2E 20 20 CF 54 48 45 52 20 43 |E USED. .THER C|
0000D6C0: 48 45 43 4B 20 54 59 50 45 53 0D 4D 41 59 20 41 |HECK TYPES.MAY A|
0000D6D0: 4C 53 4F 20 42 45 20 41 44 44 45 44 2E 0D 0D D2 |LSO BE ADDED....|
0000D6E0: C5 D0 D4 20 20 D4 48 45 20 50 52 45 46 49 58 20 |... .HE PREFIX |
0000D6F0: 43 48 41 52 41 43 54 45 52 20 C9 20 57 49 4C 4C |CHARACTER . WILL|
0000D700: 20 55 53 45 20 54 4F 20 49 4E 44 49 43 41 54 45 | USE TO INDICATE|
0000D710: 20 41 20 52 45 50 45 41 54 45 44 20 43 48 41 52 | A REPEATED CHAR|
0000D720: 41 43 54 45 52 2E 20 D4 48 49 53 0D 43 41 4E 20 |ACTER. .HIS.CAN |
0000D730: 42 45 20 41 4E 59 20 50 52 49 4E 54 41 42 4C 45 |BE ANY PRINTABLE|
0000D740: 20 43 48 41 52 41 43 54 45 52 20 4F 54 48 45 52 | CHARACTER OTHER|
0000D750: 20 54 48 41 4E 20 42 4C 41 4E 4B 20 28 57 48 49 | THAN BLANK (WHI|
0000D760: 43 48 20 44 45 4E 4F 54 45 53 20 4E 4F 20 52 45 |CH DENOTES NO RE|
0000D770: 50 45 41 54 20 43 4F 55 4E 54 0D 50 52 45 46 49 |PEAT COUNT.PREFI|
0000D780: 58 29 2C 20 42 55 54 20 22 3E 22 20 49 53 20 52 |X), BUT ">" IS R|
0000D790: 45 43 4F 4D 4D 45 4E 44 45 44 2E 20 20 C9 46 20 |ECOMMENDED. .F |
0000D7A0: 59 4F 55 20 44 4F 4E 27 54 20 52 45 53 50 4F 4E |YOU DON'T RESPON|
0000D7B0: 44 20 49 44 45 4E 54 49 43 41 4C 4C 59 2C 20 52 |D IDENTICALLY, R|
0000D7C0: 45 50 45 41 54 0D 43 4F 55 4E 54 53 20 57 49 4C |EPEAT.COUNTS WIL|
0000D7D0: 4C 20 4E 4F 54 20 42 45 20 44 4F 4E 45 2E 20 20 |L NOT BE DONE. |
0000D7E0: C7 52 4F 55 50 53 20 4F 46 20 34 20 4F 52 20 4D |.ROUPS OF 4 OR M|
0000D7F0: 4F 52 45 20 49 44 45 4E 54 49 43 41 4C 20 43 48 |ORE IDENTICAL CH|
0000D800: 41 52 41 43 54 45 52 53 20 4D 41 59 20 42 45 0D |ARACTERS MAY BE.|
0000D810: 54 52 41 4E 53 4D 49 54 54 45 44 20 4D 4F 52 45 |TRANSMITTED MORE|
0000D820: 20 45 46 46 49 43 49 45 4E 54 4C 59 20 55 53 49 | EFFICIENTLY USI|
0000D830: 4E 47 20 41 20 52 45 50 45 41 54 20 43 4F 55 4E |NG A REPEAT COUN|
0000D840: 54 2C 20 54 48 4F 55 47 48 20 41 4E 20 49 4E 44 |T, THOUGH AN IND|
0000D850: 49 56 49 44 55 41 4C 0D 49 4D 50 4C 45 4D 45 4E |IVIDUAL.IMPLEMEN|
0000D860: 54 41 54 49 4F 4E 20 4D 41 59 20 57 49 53 48 20 |TATION MAY WISH |
0000D870: 54 4F 20 53 45 54 20 41 20 48 49 47 48 45 52 20 |TO SET A HIGHER |
0000D880: 54 48 52 45 53 48 48 4F 4C 44 2E 0D 0D C3 C1 D0 |THRESHHOLD......|
0000D890: C1 D3 20 20 C1 4E 20 45 58 54 45 4E 44 41 42 4C |.. .N EXTENDABL|
0000D8A0: 45 20 42 49 54 20 4D 41 53 4B 20 45 4E 43 4F 44 |E BIT MASK ENCOD|
0000D8B0: 45 44 20 50 52 49 4E 54 41 42 4C 59 2C 20 54 4F |ED PRINTABLY, TO|
0000D8C0: 20 49 4E 44 49 43 41 54 45 20 57 48 45 54 48 45 | INDICATE WHETHE|
0000D8D0: 52 20 43 45 52 54 41 49 4E 0D 41 44 56 41 4E 43 |R CERTAIN.ADVANC|
0000D8E0: 45 44 20 43 41 50 41 42 49 4C 49 54 49 45 53 2C |ED CAPABILITIES,|
0000D8F0: 20 53 55 43 48 20 41 53 20 46 49 4C 45 2D 41 54 | SUCH AS FILE-AT|
0000D900: 54 52 49 42 55 54 45 20 50 41 43 4B 45 54 53 2C |TRIBUTE PACKETS,|
0000D910: 20 41 52 45 20 53 55 50 50 4F 52 54 45 44 2E 0D | ARE SUPPORTED..|
0000D920: 0D 5B D2 45 53 45 52 56 45 44 20 C6 49 45 4C 44 |.[.ESERVED .IELD|
0000D930: 53 5D 20 20 D4 48 45 20 4E 45 58 54 20 46 4F 55 |S] .HE NEXT FOU|
0000D940: 52 20 46 49 45 4C 44 53 20 41 52 45 20 52 45 53 |R FIELDS ARE RES|
0000D950: 45 52 56 45 44 20 46 4F 52 20 46 55 54 55 52 45 |ERVED FOR FUTURE|
0000D960: 20 55 53 45 2E 20 D3 49 54 45 53 0D 57 49 53 48 | USE. .ITES.WISH|
0000D970: 49 4E 47 20 54 4F 20 41 44 44 20 54 48 45 49 52 |ING TO ADD THEIR|
0000D980: 20 4F 57 4E 20 50 41 52 41 4D 45 54 45 52 53 20 | OWN PARAMETERS |
0000D990: 54 4F 20 54 48 45 20 49 4E 49 54 49 41 4C 20 43 |TO THE INITIAL C|
0000D9A0: 4F 4E 4E 45 43 54 49 4F 4E 20 45 58 43 48 41 4E |ONNECTION EXCHAN|
0000D9B0: 47 45 20 53 48 4F 55 4C 44 0D 53 54 41 52 54 20 |GE SHOULD.START |
0000D9C0: 41 54 20 54 48 45 20 46 49 46 54 48 20 46 49 45 |AT THE FIFTH FIE|
0000D9D0: 4C 44 20 41 46 54 45 52 20 54 48 45 20 43 41 50 |LD AFTER THE CAP|
0000D9E0: 41 42 49 4C 49 54 59 20 4D 41 53 4B 20 49 4E 20 |ABILITY MASK IN |
0000D9F0: 4F 52 44 45 52 20 54 4F 20 52 45 4D 41 49 4E 0D |ORDER TO REMAIN.|
0000DA00: 43 4F 4D 50 41 54 49 42 4C 45 20 57 49 54 48 20 |COMPATIBLE WITH |
0000DA10: 4F 54 48 45 52 20 CB C5 D2 CD C9 D4 20 50 52 4F |OTHER ...... PRO|
0000DA20: 47 52 41 4D 53 2E 0D 0D 0D CE 41 54 55 52 41 4C |GRAMS.....ATURAL|
0000DA30: 4C 59 2C 20 54 48 45 20 54 48 52 45 45 20 50 52 |LY, THE THREE PR|
0000DA40: 45 46 49 58 20 43 48 41 52 41 43 54 45 52 53 20 |EFIX CHARACTERS |
0000DA50: 4D 55 53 54 20 42 45 20 44 49 53 54 49 4E 43 54 |MUST BE DISTINCT|
0000DA60: 20 41 4E 44 20 53 48 4F 55 4C 44 20 42 45 20 43 | AND SHOULD BE C|
0000DA70: 48 4F 53 45 4E 20 54 4F 0D 42 45 20 55 4E 43 4F |HOSEN TO.BE UNCO|
0000DA80: 4D 4D 4F 4E 4C 59 20 55 53 45 44 20 50 52 49 4E |MMONLY USED PRIN|
0000DA90: 54 41 42 4C 45 20 43 48 41 52 41 43 54 45 52 53 |TABLE CHARACTERS|
0000DAA0: 2C 20 54 4F 20 4D 49 4E 49 4D 49 5A 45 20 46 55 |, TO MINIMIZE FU|
0000DAB0: 52 54 48 45 52 20 4F 56 45 52 48 45 41 44 20 46 |RTHER OVERHEAD F|
0000DAC0: 52 4F 4D 0D 48 41 56 49 4E 47 20 54 4F 20 50 52 |ROM.HAVING TO PR|
0000DAD0: 45 46 49 58 20 54 48 45 4D 20 57 48 45 4E 20 54 |EFIX THEM WHEN T|
0000DAE0: 48 45 59 20 41 52 45 20 46 4F 55 4E 44 20 49 4E |HEY ARE FOUND IN|
0000DAF0: 20 54 48 45 20 44 41 54 41 2E 0D 0D D4 52 41 49 | THE DATA....RAI|
0000DB00: 4C 49 4E 47 20 46 49 45 4C 44 53 20 57 49 54 48 |LING FIELDS WITH|
0000DB10: 49 4E 20 54 48 45 20 C4 C1 D4 C1 20 46 49 45 4C |IN THE .... FIEL|
0000DB20: 44 20 4D 41 59 20 42 45 20 4F 4D 49 54 54 45 44 |D MAY BE OMITTED|
0000DB30: 2C 20 49 4E 20 57 48 49 43 48 20 43 41 53 45 20 |, IN WHICH CASE |
0000DB40: 54 48 45 59 20 57 49 4C 4C 0D 41 53 53 55 4D 45 |THEY WILL.ASSUME|
0000DB50: 20 41 50 50 52 4F 50 52 49 41 54 45 20 44 45 46 | APPROPRIATE DEF|
0000DB60: 41 55 4C 54 53 2E 20 20 C4 45 46 41 55 4C 54 53 |AULTS. .EFAULTS|
0000DB70: 20 46 4F 52 20 49 4E 54 45 52 4D 45 44 49 41 54 | FOR INTERMEDIAT|
0000DB80: 45 20 46 49 45 4C 44 53 20 43 41 4E 20 42 45 20 |E FIELDS CAN BE |
0000DB90: 45 4C 45 43 54 45 44 0D 42 59 20 53 45 54 54 49 |ELECTED.BY SETTI|
0000DBA0: 4E 47 20 54 48 4F 53 45 20 46 49 45 4C 44 53 20 |NG THOSE FIELDS |
0000DBB0: 54 4F 20 42 4C 41 4E 4B 2E 20 20 C5 56 45 52 59 |TO BLANK. .VERY|
0000DBC0: 20 50 41 52 41 4D 45 54 45 52 20 48 41 53 20 41 | PARAMETER HAS A|
0000DBD0: 4E 20 41 50 50 52 4F 50 52 49 41 54 45 20 44 45 |N APPROPRIATE DE|
0000DBE0: 46 41 55 4C 54 2C 0D 41 4E 44 20 49 4E 20 46 41 |FAULT,.AND IN FA|
0000DBF0: 43 54 20 54 48 45 20 45 4E 54 49 52 45 20 44 41 |CT THE ENTIRE DA|
0000DC00: 54 41 20 46 49 45 4C 44 20 4F 46 20 54 48 45 20 |TA FIELD OF THE |
0000DC10: D3 45 4E 44 20 C9 4E 49 54 20 50 41 43 4B 45 54 |.END .NIT PACKET|
0000DC20: 20 4F 52 20 49 54 53 20 C1 C3 CB 20 4D 41 59 20 | OR ITS ... MAY |
0000DC30: 42 45 0D 4C 45 46 54 20 45 4D 50 54 59 20 54 4F |BE.LEFT EMPTY TO|
0000DC40: 20 41 43 43 45 50 54 20 41 4C 4C 20 44 45 46 41 | ACCEPT ALL DEFA|
0000DC50: 55 4C 54 53 2E 20 20 D4 48 45 20 4D 4F 52 45 20 |ULTS. .HE MORE |
0000DC60: 45 58 4F 54 49 43 20 50 41 52 41 4D 41 54 45 52 |EXOTIC PARAMATER|
0000DC70: 53 20 41 52 45 20 41 54 20 54 48 45 20 45 4E 44 |S ARE AT THE END|
0000DC80: 2C 0D 41 4E 44 20 52 45 46 4C 45 43 54 20 4D 4F |,.AND REFLECT MO|
0000DC90: 52 45 20 52 45 43 45 4E 54 20 44 45 56 45 4C 4F |RE RECENT DEVELO|
0000DCA0: 50 4D 45 4E 54 53 20 49 4E 20 54 48 45 20 CB C5 |PMENTS IN THE ..|
0000DCB0: D2 CD C9 D4 20 50 52 4F 54 4F 43 4F 4C 3B 20 45 |.... PROTOCOL; E|
0000DCC0: 41 52 4C 49 45 52 0D 49 4D 50 4C 45 4D 45 4E 54 |ARLIER.IMPLEMENT|
0000DCD0: 41 54 49 4F 4E 53 20 43 41 4E 20 53 54 49 4C 4C |ATIONS CAN STILL|
0000DCE0: 20 43 4F 4D 4D 55 4E 49 43 41 54 45 20 57 49 54 | COMMUNICATE WIT|
0000DCF0: 48 20 4E 45 57 45 52 20 4F 4E 45 53 2C 20 53 49 |H NEWER ONES, SI|
0000DD00: 4E 43 45 20 54 48 45 52 45 20 57 49 4C 4C 20 4E |NCE THERE WILL N|
0000DD10: 4F 54 20 42 45 0D 41 47 52 45 45 4D 45 4E 54 20 |OT BE.AGREEMENT |
0000DD20: 54 4F 20 55 53 45 20 54 48 45 53 45 20 4F 50 54 |TO USE THESE OPT|
0000DD30: 49 4F 4E 53 2E 20 D4 48 45 20 D3 45 4E 44 2D C9 |IONS. .HE .END-.|
0000DD40: 4E 49 54 20 4D 45 43 48 41 4E 49 53 4D 20 50 52 |NIT MECHANISM PR|
0000DD50: 45 53 45 52 56 45 53 20 43 4F 4D 50 41 54 49 42 |ESERVES COMPATIB|
0000DD60: 49 4C 49 54 59 0D 46 52 4F 4D 20 54 48 45 20 56 |ILITY.FROM THE V|
0000DD70: 45 52 59 20 45 41 52 4C 49 45 53 54 20 CB C5 D2 |ERY EARLIEST ...|
0000DD80: CD C9 D4 20 54 4F 20 54 48 45 20 56 45 52 59 20 |... TO THE VERY |
0000DD90: 4E 45 57 45 53 54 2E 20 D4 48 45 52 45 20 49 53 |NEWEST. .HERE IS|
0000DDA0: 20 4E 4F 20 50 52 4F 54 52 41 43 54 45 44 0D 4E | NO PROTRACTED.N|
0000DDB0: 45 47 4F 54 49 41 54 49 4F 4E 3B 20 45 56 45 52 |EGOTIATION; EVER|
0000DDC0: 59 54 48 49 4E 47 20 4D 55 53 54 20 42 45 20 53 |YTHING MUST BE S|
0000DDD0: 45 54 54 4C 45 44 20 49 4E 20 41 20 53 49 4E 47 |ETTLED IN A SING|
0000DDE0: 4C 45 20 45 58 43 48 41 4E 47 45 2E 20 20 D3 4F |LE EXCHANGE. .O|
0000DDF0: 4D 45 20 50 41 52 41 4D 45 54 45 52 53 2C 0D 48 |ME PARAMETERS,.H|
0000DE00: 4F 57 45 56 45 52 2C 20 41 52 45 20 4F 55 54 53 |OWEVER, ARE OUTS|
0000DE10: 49 44 45 20 54 48 45 20 53 43 4F 50 45 20 4F 46 |IDE THE SCOPE OF|
0000DE20: 20 54 48 49 53 20 45 58 43 48 41 4E 47 45 20 41 | THIS EXCHANGE A|
0000DE30: 4E 44 20 4D 55 53 54 20 42 45 20 53 45 54 20 45 |ND MUST BE SET E|
0000DE40: 56 45 4E 20 42 45 46 4F 52 45 20 54 48 45 0D 56 |VEN BEFORE THE.V|
0000DE50: 45 52 59 20 46 49 52 53 54 20 50 41 43 4B 45 54 |ERY FIRST PACKET|
0000DE60: 20 49 53 20 53 45 4E 54 2E 20 20 C6 4F 52 20 49 | IS SENT. .OR I|
0000DE70: 4E 53 54 41 4E 43 45 2C 20 49 46 20 54 48 45 20 |NSTANCE, IF THE |
0000DE80: 52 45 43 45 49 56 49 4E 47 20 43 4F 4D 50 55 54 |RECEIVING COMPUT|
0000DE90: 45 52 20 43 41 4E 20 4F 4E 4C 59 0D 52 45 41 44 |ER CAN ONLY.READ|
0000DEA0: 20 43 48 41 52 41 43 54 45 52 53 20 57 49 54 48 | CHARACTERS WITH|
0000DEB0: 20 4F 44 44 20 50 41 52 49 54 59 20 42 55 54 20 | ODD PARITY BUT |
0000DEC0: 54 48 45 20 53 45 4E 44 49 4E 47 20 43 4F 4D 50 |THE SENDING COMP|
0000DED0: 55 54 45 52 20 53 45 4E 44 53 20 54 48 45 4D 20 |UTER SENDS THEM |
0000DEE0: 57 49 54 48 20 45 56 45 4E 0D 50 41 52 49 54 59 |WITH EVEN.PARITY|
0000DEF0: 2C 20 54 48 45 20 D3 45 4E 44 2D C9 4E 49 54 20 |, THE .END-.NIT |
0000DF00: 50 41 43 4B 45 54 20 57 49 4C 4C 20 4E 45 56 45 |PACKET WILL NEVE|
0000DF10: 52 20 41 52 52 49 56 45 20 53 55 43 43 45 53 53 |R ARRIVE SUCCESS|
0000DF20: 46 55 4C 4C 59 2E 20 C9 4E 20 43 41 53 45 53 20 |FULLY. .N CASES |
0000DF30: 4C 49 4B 45 0D 54 48 49 53 2C 20 54 48 45 20 55 |LIKE.THIS, THE U|
0000DF40: 53 45 52 20 4D 41 59 20 48 41 56 45 20 54 4F 20 |SER MAY HAVE TO |
0000DF50: 49 53 53 55 45 20 53 4F 4D 45 20 50 52 45 4C 49 |ISSUE SOME PRELI|
0000DF60: 4D 49 4E 41 52 59 20 43 4F 4D 4D 41 4E 44 53 20 |MINARY COMMANDS |
0000DF70: 54 4F 20 49 4E 46 4F 52 4D 20 4F 4E 45 20 4F 52 |TO INFORM ONE OR|
0000DF80: 0D 42 4F 54 48 20 CB C5 D2 CD C9 D4 53 20 41 42 |.BOTH ......S AB|
0000DF90: 4F 55 54 20 54 48 45 20 56 41 47 41 52 49 45 53 |OUT THE VAGARIES|
0000DFA0: 20 4F 46 20 54 48 45 20 4F 54 48 45 52 20 53 59 | OF THE OTHER SY|
0000DFB0: 53 54 45 4D 2E 0D C1 4E 4F 54 48 45 52 20 45 58 |STEM...NOTHER EX|
0000DFC0: 41 4D 50 4C 45 20 49 53 20 54 48 45 20 20 50 41 |AMPLE IS THE PA|
0000DFD0: 43 4B 45 54 20 54 45 52 4D 49 4E 41 54 4F 52 20 |CKET TERMINATOR |
0000DFE0: 28 C5 CF CC 29 20 4D 45 4E 54 49 4F 4E 45 44 20 |(...) MENTIONED |
0000DFF0: 41 42 4F 56 45 20 2D 20 49 46 20 54 48 45 0D 52 |ABOVE - IF THE.R|
0000E000: 45 43 45 49 56 49 4E 47 20 CB C5 D2 CD C9 D4 20 |ECEIVING ...... |
0000E010: 52 45 51 55 49 52 45 53 20 4F 4E 45 20 54 48 41 |REQUIRES ONE THA|
0000E020: 54 20 54 48 45 20 53 45 4E 44 49 4E 47 20 CB C5 |T THE SENDING ..|
0000E030: D2 CD C9 D4 20 44 4F 45 53 4E 27 54 20 4B 4E 4F |.... DOESN'T KNO|
0000E040: 57 20 41 42 4F 55 54 2C 20 54 48 45 0D D3 45 4E |W ABOUT, THE..EN|
0000E050: 44 2D C9 4E 49 54 20 57 49 4C 4C 20 4E 45 56 45 |D-.NIT WILL NEVE|
0000E060: 52 20 47 45 54 20 54 48 52 4F 55 47 48 2E 0D 0D |R GET THROUGH...|
0000E070: C6 4F 52 20 54 48 45 53 45 20 52 45 41 53 4F 4E |.OR THESE REASON|
0000E080: 53 2C 20 4D 4F 53 54 20 49 4D 50 4C 45 4D 45 4E |S, MOST IMPLEMEN|
0000E090: 54 41 54 49 4F 4E 53 20 4F 46 20 CB C5 D2 CD C9 |TATIONS OF .....|
0000E0A0: D4 20 50 52 4F 56 49 44 45 20 D3 C5 D4 20 43 4F |. PROVIDE ... CO|
0000E0B0: 4D 4D 41 4E 44 53 20 46 4F 52 20 41 4C 4C 0D 54 |MMANDS FOR ALL.T|
0000E0C0: 48 45 20 50 41 52 41 4D 45 54 45 52 53 20 4C 49 |HE PARAMETERS LI|
0000E0D0: 53 54 45 44 20 41 42 4F 56 45 2C 20 41 4E 44 20 |STED ABOVE, AND |
0000E0E0: 53 4F 4D 45 20 4F 54 48 45 52 53 20 41 53 20 57 |SOME OTHERS AS W|
0000E0F0: 45 4C 4C 2E 0D 0D 0D D2 55 4C 45 53 20 41 4E 44 |ELL.....ULES AND|
0000E100: 20 C8 45 55 52 49 53 54 49 43 53 0D 0D C4 55 52 | .EURISTICS...UR|
0000E110: 49 4E 47 20 41 20 46 49 4C 45 20 54 52 41 4E 53 |ING A FILE TRANS|
0000E120: 46 45 52 2C 20 4F 4E 45 20 CB C5 D2 CD C9 D4 20 |FER, ONE ...... |
0000E130: 53 45 4E 44 53 20 49 4E 46 4F 52 4D 41 54 49 4F |SENDS INFORMATIO|
0000E140: 4E 20 50 41 43 4B 45 54 53 20 2D 20 46 49 4C 45 |N PACKETS - FILE|
0000E150: 20 48 45 41 44 45 52 53 2C 0D 44 41 54 41 2C 20 | HEADERS,.DATA, |
0000E160: 41 4E 44 20 53 4F 20 46 4F 52 54 48 2C 20 41 4E |AND SO FORTH, AN|
0000E170: 44 20 54 48 45 20 4F 54 48 45 52 20 CB C5 D2 CD |D THE OTHER ....|
0000E180: C9 D4 20 53 45 4E 44 53 20 4F 4E 4C 59 20 C1 C3 |.. SENDS ONLY ..|
0000E190: CB 53 20 4F 52 20 CE C1 CB 53 20 49 4E 20 52 45 |.S OR ...S IN RE|
0000E1A0: 53 50 4F 4E 53 45 2E 0D D4 48 45 20 4D 4F 53 54 |SPONSE...HE MOST|
0000E1B0: 20 49 4D 50 4F 52 54 41 4E 54 20 52 55 4C 45 20 | IMPORTANT RULE |
0000E1C0: 49 4E 20 54 48 45 20 CB C5 D2 CD C9 D4 20 50 52 |IN THE ...... PR|
0000E1D0: 4F 54 4F 43 4F 4C 20 49 53 0D 0D 31 2E 29 20 20 |OTOCOL IS..1.) |
0000E1E0: D7 41 49 54 20 46 4F 52 20 41 20 52 45 53 50 4F |.AIT FOR A RESPO|
0000E1F0: 4E 53 45 20 42 45 46 4F 52 45 20 53 45 4E 44 49 |NSE BEFORE SENDI|
0000E200: 4E 47 20 54 48 45 20 4E 45 58 54 20 50 41 43 4B |NG THE NEXT PACK|
0000E210: 45 54 2E 0D D4 48 49 53 20 50 52 45 56 45 4E 54 |ET...HIS PREVENT|
0000E220: 53 20 42 55 46 46 45 52 20 4F 56 45 52 52 55 4E |S BUFFER OVERRUN|
0000E230: 53 2C 20 41 4E 44 20 41 4C 4C 4F 57 53 20 50 41 |S, AND ALLOWS PA|
0000E240: 52 54 49 43 49 50 41 54 49 4F 4E 20 42 59 20 48 |RTICIPATION BY H|
0000E250: 41 4C 46 20 44 55 50 4C 45 58 20 53 59 53 54 45 |ALF DUPLEX SYSTE|
0000E260: 4D 53 2E 0D CF 46 20 43 4F 55 52 53 45 2C 20 CB |MS...F COURSE, .|
0000E270: C5 D2 CD C9 D4 20 53 48 4F 55 4C 44 20 4E 4F 54 |..... SHOULD NOT|
0000E280: 20 57 41 49 54 20 46 4F 52 45 56 45 52 3B 20 41 | WAIT FOREVER; A|
0000E290: 20 54 49 4D 45 4F 55 54 20 53 48 4F 55 4C 44 20 | TIMEOUT SHOULD |
0000E2A0: 4F 43 43 55 52 20 41 46 54 45 52 20 41 20 46 45 |OCCUR AFTER A FE|
0000E2B0: 57 0D 53 45 43 4F 4E 44 53 20 49 46 20 54 48 45 |W.SECONDS IF THE|
0000E2C0: 20 45 58 50 45 43 54 45 44 20 50 41 43 4B 45 54 | EXPECTED PACKET|
0000E2D0: 20 48 41 53 20 4E 4F 54 20 41 52 52 49 56 45 44 | HAS NOT ARRIVED|
0000E2E0: 2E 20 20 D5 50 4F 4E 20 54 49 4D 45 4F 55 54 2C |. .PON TIMEOUT,|
0000E2F0: 20 41 20 53 45 4E 44 49 4E 47 20 CB C5 D2 CD C9 | A SENDING .....|
0000E300: D4 0D 52 45 54 52 41 4E 53 4D 49 54 53 20 54 48 |..RETRANSMITS TH|
0000E310: 45 20 43 55 52 52 45 4E 54 20 50 41 43 4B 45 54 |E CURRENT PACKET|
0000E320: 3B 20 41 20 52 45 43 45 49 56 49 4E 47 20 CB C5 |; A RECEIVING ..|
0000E330: D2 CD C9 D4 20 52 45 2D C1 C3 CB 53 20 54 48 45 |.... RE-...S THE|
0000E340: 20 43 55 52 52 45 4E 54 20 50 41 43 4B 45 54 0D | CURRENT PACKET.|
0000E350: 4F 52 20 CE C1 CB 53 20 54 48 45 20 45 58 50 45 |OR ...S THE EXPE|
0000E360: 43 54 45 44 20 4F 4E 45 2E 0D D3 4F 4D 45 20 49 |CTED ONE...OME I|
0000E370: 4E 54 45 52 45 53 54 49 4E 47 20 48 45 55 52 49 |NTERESTING HEURI|
0000E380: 53 54 49 43 53 20 41 52 45 20 55 53 45 44 20 49 |STICS ARE USED I|
0000E390: 4E 20 54 48 45 20 CB C5 D2 CD C9 D4 20 50 52 4F |N THE ...... PRO|
0000E3A0: 54 4F 43 4F 4C 20 54 4F 20 42 4F 4F 53 54 20 45 |TOCOL TO BOOST E|
0000E3B0: 46 46 49 43 49 45 4E 43 59 0D 41 4E 44 20 49 4D |FFICIENCY.AND IM|
0000E3C0: 50 52 4F 56 45 20 45 52 52 4F 52 20 52 45 43 4F |PROVE ERROR RECO|
0000E3D0: 56 45 52 59 2E 20 20 C1 20 4E 55 4D 42 45 52 20 |VERY. . NUMBER |
0000E3E0: 4F 46 20 49 4D 50 4F 52 54 41 4E 54 20 52 55 4C |OF IMPORTANT RUL|
0000E3F0: 45 53 20 54 41 4B 45 20 43 41 52 45 20 4F 46 20 |ES TAKE CARE OF |
0000E400: 54 48 45 20 43 41 53 45 53 0D 57 48 45 4E 20 50 |THE CASES.WHEN P|
0000E410: 41 43 4B 45 54 53 20 41 52 45 20 4C 4F 53 54 20 |ACKETS ARE LOST |
0000E420: 49 4E 20 54 52 41 4E 53 4D 49 53 53 49 4F 4E 2E |IN TRANSMISSION.|
0000E430: 20 20 D4 48 45 20 46 49 52 53 54 20 43 41 4E 20 | .HE FIRST CAN |
0000E440: 42 45 20 53 54 41 54 45 44 20 41 53 0D 0D 32 2E |BE STATED AS..2.|
0000E450: 29 20 20 C1 20 CE C1 CB 20 46 4F 52 20 54 48 45 |) . ... FOR THE|
0000E460: 20 4E 45 58 54 20 50 41 43 4B 45 54 20 49 4D 50 | NEXT PACKET IMP|
0000E470: 4C 49 45 53 20 41 4E 20 C1 C3 CB 20 46 4F 52 20 |LIES AN ... FOR |
0000E480: 54 48 45 20 43 55 52 52 45 4E 54 20 50 41 43 4B |THE CURRENT PACK|
0000E490: 45 54 2E 0D C1 20 CE C1 CB 20 57 49 54 48 20 50 |ET... ... WITH P|
0000E4A0: 41 43 4B 45 54 20 4E 55 4D 42 45 52 20 4E 2B 31 |ACKET NUMBER N+1|
0000E4B0: 20 4D 45 41 4E 53 20 54 48 45 20 52 45 43 45 49 | MEANS THE RECEI|
0000E4C0: 56 49 4E 47 20 CB C5 D2 CD C9 D4 20 47 4F 54 20 |VING ...... GOT |
0000E4D0: 50 41 43 4B 45 54 20 4E 2C 20 53 45 4E 54 20 41 |PACKET N, SENT A|
0000E4E0: 4E 0D C1 C3 CB 20 54 48 41 54 20 57 41 53 20 4E |N.... THAT WAS N|
0000E4F0: 45 56 45 52 20 52 45 43 45 49 56 45 44 2C 20 41 |EVER RECEIVED, A|
0000E500: 4E 44 20 4E 4F 54 20 4B 4E 4F 57 49 4E 47 20 54 |ND NOT KNOWING T|
0000E510: 48 41 54 20 54 48 45 20 C1 C3 CB 20 44 49 44 4E |HAT THE ... DIDN|
0000E520: 27 54 20 47 45 54 20 54 48 52 4F 55 47 48 0D 28 |'T GET THROUGH.(|
0000E530: 53 49 4E 43 45 20 57 45 20 44 4F 4E 27 54 20 C1 |SINCE WE DON'T .|
0000E540: C3 CB 20 41 4E 20 C1 C3 CB 29 2C 20 49 53 20 4E |.. AN ...), IS N|
0000E550: 4F 57 20 57 41 49 54 49 4E 47 20 46 4F 52 20 50 |OW WAITING FOR P|
0000E560: 41 43 4B 45 54 20 4E 2B 31 2C 20 57 48 49 43 48 |ACKET N+1, WHICH|
0000E570: 20 57 41 53 20 4E 45 56 45 52 0D 53 45 4E 54 2E | WAS NEVER.SENT.|
0000E580: 20 20 C9 4E 20 54 48 49 53 20 43 41 53 45 2C 20 | .N THIS CASE, |
0000E590: 57 45 20 53 49 4D 50 4C 59 20 53 45 4E 44 20 50 |WE SIMPLY SEND P|
0000E5A0: 41 43 4B 45 54 20 4E 2B 31 2E 20 C1 4E 20 49 4D |ACKET N+1. .N IM|
0000E5B0: 50 4F 52 54 41 4E 54 20 45 58 43 45 50 54 49 4F |PORTANT EXCEPTIO|
0000E5C0: 4E 20 49 53 20 57 48 45 4E 0D 54 48 45 20 4D 49 |N IS WHEN.THE MI|
0000E5D0: 53 53 49 4E 47 20 C1 C3 CB 20 49 53 20 46 4F 52 |SSING ... IS FOR|
0000E5E0: 20 41 20 D3 45 4E 44 2D C9 4E 49 54 20 50 41 43 | A .END-.NIT PAC|
0000E5F0: 4B 45 54 3B 20 44 4F 20 59 4F 55 20 53 45 45 20 |KET; DO YOU SEE |
0000E600: 57 48 59 3F 20 20 D4 48 45 20 4E 45 58 54 20 52 |WHY? .HE NEXT R|
0000E610: 55 4C 45 2C 0D 0D 33 2E 29 20 20 C1 C3 CB 20 41 |ULE,..3.) ... A|
0000E620: 4E 44 20 44 49 53 43 41 52 44 20 52 45 44 55 4E |ND DISCARD REDUN|
0000E630: 44 41 4E 54 20 50 41 43 4B 45 54 53 2E 0D 48 41 |DANT PACKETS..HA|
0000E640: 4E 44 4C 45 53 20 54 48 45 20 53 49 54 55 41 54 |NDLES THE SITUAT|
0000E650: 49 4F 4E 20 57 48 45 52 45 20 54 48 45 20 53 41 |ION WHERE THE SA|
0000E660: 4D 45 20 50 41 43 4B 45 54 20 41 52 52 49 56 45 |ME PACKET ARRIVE|
0000E670: 53 20 41 47 41 49 4E 2E 20 20 D4 48 45 20 53 45 |S AGAIN. .HE SE|
0000E680: 4E 44 49 4E 47 20 CB C5 D2 CD C9 D4 0D 54 49 4D |NDING .......TIM|
0000E690: 45 44 20 4F 55 54 20 57 41 49 54 49 4E 47 20 46 |ED OUT WAITING F|
0000E6A0: 4F 52 20 41 4E 20 C1 C3 CB 20 57 48 49 43 48 20 |OR AN ... WHICH |
0000E6B0: 57 41 53 20 53 45 4E 54 2C 20 42 55 54 20 4C 4F |WAS SENT, BUT LO|
0000E6C0: 53 54 2C 20 41 4E 44 20 52 45 54 52 41 4E 53 4D |ST, AND RETRANSM|
0000E6D0: 49 54 54 45 44 20 54 48 45 0D 50 41 43 4B 45 54 |ITTED THE.PACKET|
0000E6E0: 2E 20 20 D4 48 45 20 52 45 43 45 49 56 45 52 20 |. .HE RECEIVER |
0000E6F0: 4D 55 53 54 20 44 49 53 43 41 52 44 20 54 48 45 |MUST DISCARD THE|
0000E700: 20 52 45 44 55 4E 44 41 4E 54 20 44 41 54 41 20 | REDUNDANT DATA |
0000E710: 41 4E 44 20 C1 C3 CB 20 54 48 45 20 50 41 43 4B |AND ... THE PACK|
0000E720: 45 54 20 41 47 41 49 4E 3B 0D 54 4F 20 44 4F 20 |ET AGAIN;.TO DO |
0000E730: 4F 54 48 45 52 57 49 53 45 20 43 4F 55 4C 44 20 |OTHERWISE COULD |
0000E740: 48 41 56 45 20 55 4E 44 45 53 49 52 41 42 4C 45 |HAVE UNDESIRABLE|
0000E750: 20 45 46 46 45 43 54 53 2C 20 4C 49 4B 45 20 41 | EFFECTS, LIKE A|
0000E760: 44 44 49 4E 47 20 54 48 45 20 53 41 4D 45 20 44 |DDING THE SAME D|
0000E770: 41 54 41 20 54 4F 20 41 0D 46 49 4C 45 20 54 57 |ATA TO A.FILE TW|
0000E780: 49 43 45 20 4F 52 20 4F 50 45 4E 49 4E 47 20 54 |ICE OR OPENING T|
0000E790: 48 45 20 53 41 4D 45 20 46 49 4C 45 20 4D 55 4C |HE SAME FILE MUL|
0000E7A0: 54 49 50 4C 45 20 54 49 4D 45 53 2E 20 CE 4F 54 |TIPLE TIMES. .OT|
0000E7B0: 45 20 54 48 41 54 20 54 48 45 20 53 49 54 55 41 |E THAT THE SITUA|
0000E7C0: 54 49 4F 4E 0D 52 45 53 55 4C 54 49 4E 47 20 46 |TION.RESULTING F|
0000E7D0: 52 4F 4D 20 41 20 4C 4F 53 54 20 C1 C3 CB 20 44 |ROM A LOST ... D|
0000E7E0: 45 50 45 4E 44 53 20 55 50 4F 4E 20 57 48 49 43 |EPENDS UPON WHIC|
0000E7F0: 48 20 53 49 44 45 20 54 49 4D 45 53 20 4F 55 54 |H SIDE TIMES OUT|
0000E800: 20 46 49 52 53 54 2E 0D 0D CB C5 D2 CD C9 D4 20 | FIRST......... |
0000E810: 4D 55 53 54 20 48 41 4E 44 4C 45 20 41 4E 4F 54 |MUST HANDLE ANOT|
0000E820: 48 45 52 20 53 49 54 55 41 54 49 4F 4E 20 41 52 |HER SITUATION AR|
0000E830: 49 53 49 4E 47 20 46 52 4F 4D 20 50 4F 53 53 49 |ISING FROM POSSI|
0000E840: 42 4C 45 20 4C 4F 53 54 20 50 41 43 4B 45 54 53 |BLE LOST PACKETS|
0000E850: 3A 0D 0D 34 2E 29 20 20 CE C1 CB 20 54 48 45 20 |:..4.) ... THE |
0000E860: 45 58 50 45 43 54 45 44 20 43 4F 4D 4D 41 4E 44 |EXPECTED COMMAND|
0000E870: 2E 0D D4 48 45 20 50 4F 54 45 4E 54 49 41 4C 20 |...HE POTENTIAL |
0000E880: 50 52 4F 42 4C 45 4D 20 4F 43 43 55 52 53 20 49 |PROBLEM OCCURS I|
0000E890: 4E 20 45 49 54 48 45 52 20 54 48 45 20 D2 45 43 |N EITHER THE .EC|
0000E8A0: 45 49 56 45 20 C9 4E 49 54 20 53 54 41 54 45 20 |EIVE .NIT STATE |
0000E8B0: 4F 52 20 57 48 45 4E 20 41 20 CB C5 D2 CD C9 D4 |OR WHEN A ......|
0000E8C0: 0D 53 45 52 56 45 52 20 49 53 20 57 41 49 54 49 |.SERVER IS WAITI|
0000E8D0: 4E 47 20 46 4F 52 20 41 20 43 4F 4D 4D 41 4E 44 |NG FOR A COMMAND|
0000E8E0: 2E 20 20 C9 4E 20 45 49 54 48 45 52 20 43 41 53 |. .N EITHER CAS|
0000E8F0: 45 20 CB C5 D2 CD C9 D4 20 57 4F 4E 27 54 20 4B |E ...... WON'T K|
0000E900: 4E 4F 57 20 57 48 45 54 48 45 52 0D 43 4F 4D 4D |NOW WHETHER.COMM|
0000E910: 55 4E 49 43 41 54 49 4F 4E 20 48 41 53 20 42 45 |UNICATION HAS BE|
0000E920: 47 55 4E 20 49 46 20 54 48 45 20 4F 54 48 45 52 |GUN IF THE OTHER|
0000E930: 20 53 49 44 45 27 53 20 49 4E 49 54 49 41 4C 20 | SIDE'S INITIAL |
0000E940: 50 41 43 4B 45 54 20 57 41 53 20 4C 4F 53 54 2E |PACKET WAS LOST.|
0000E950: 20 20 CB C5 D2 CD C9 D4 0D 43 41 4E 27 54 20 41 | .......CAN'T A|
0000E960: 53 53 55 4D 45 20 54 48 45 20 4F 54 48 45 52 20 |SSUME THE OTHER |
0000E970: 53 49 44 45 20 57 49 4C 4C 20 54 49 4D 45 20 4F |SIDE WILL TIME O|
0000E980: 55 54 20 41 4E 44 20 52 45 54 52 41 4E 53 4D 49 |UT AND RETRANSMI|
0000E990: 54 2C 20 53 4F 20 49 54 20 4D 55 53 54 20 43 48 |T, SO IT MUST CH|
0000E9A0: 45 43 4B 0D 50 45 52 49 4F 44 49 43 41 4C 4C 59 |ECK.PERIODICALLY|
0000E9B0: 20 42 59 20 53 45 4E 44 49 4E 47 20 41 20 CE C1 | BY SENDING A ..|
0000E9C0: CB 20 46 4F 52 20 50 41 43 4B 45 54 20 5A 45 52 |. FOR PACKET ZER|
0000E9D0: 4F 2E 20 20 C9 46 20 CB C5 D2 CD C9 D4 20 47 45 |O. .F ...... GE|
0000E9E0: 54 53 20 4E 4F 20 52 45 53 50 4F 4E 53 45 20 49 |TS NO RESPONSE I|
0000E9F0: 54 0D 41 53 53 55 4D 45 53 20 4E 4F 54 48 49 4E |T.ASSUMES NOTHIN|
0000EA00: 47 20 48 41 53 20 48 41 50 50 45 4E 45 44 20 59 |G HAS HAPPENED Y|
0000EA10: 45 54 20 41 4E 44 20 47 4F 45 53 20 42 41 43 4B |ET AND GOES BACK|
0000EA20: 20 54 4F 20 53 4C 45 45 50 20 46 4F 52 20 41 20 | TO SLEEP FOR A |
0000EA30: 57 48 49 4C 45 2E 0D C2 55 54 20 53 45 4E 44 49 |WHILE...UT SENDI|
0000EA40: 4E 47 20 50 45 52 49 4F 44 49 43 20 CE C1 CB 53 |NG PERIODIC ...S|
0000EA50: 20 4F 50 45 4E 53 20 54 48 45 20 44 4F 4F 52 20 | OPENS THE DOOR |
0000EA60: 54 4F 20 54 48 45 20 42 55 46 46 45 52 49 4E 47 |TO THE BUFFERING|
0000EA70: 20 50 52 4F 42 4C 45 4D 2E 20 20 D3 4F 4D 45 0D | PROBLEM. .OME.|
0000EA80: 53 59 53 54 45 4D 53 20 42 55 46 46 45 52 20 49 |SYSTEMS BUFFER I|
0000EA90: 4E 50 55 54 20 46 4F 52 20 41 20 44 45 56 49 43 |NPUT FOR A DEVIC|
0000EAA0: 45 3B 20 57 48 45 4E 20 41 20 50 52 4F 47 52 41 |E; WHEN A PROGRA|
0000EAB0: 4D 20 49 53 4E 27 54 20 4C 4F 4F 4B 49 4E 47 20 |M ISN'T LOOKING |
0000EAC0: 46 4F 52 20 49 4E 50 55 54 20 53 4F 4D 45 0D 4F |FOR INPUT SOME.O|
0000EAD0: 52 20 41 4C 4C 20 54 48 45 20 49 4E 50 55 54 20 |R ALL THE INPUT |
0000EAE0: 49 53 20 53 41 56 45 44 20 42 59 20 54 48 45 20 |IS SAVED BY THE |
0000EAF0: 43 4F 4D 50 55 54 45 52 20 46 4F 52 20 46 55 54 |COMPUTER FOR FUT|
0000EB00: 55 52 45 20 52 45 51 55 45 53 54 53 2E 20 20 D4 |URE REQUESTS. .|
0000EB10: 48 49 53 20 43 41 4E 20 43 41 55 53 45 0D 50 52 |HIS CAN CAUSE.PR|
0000EB20: 4F 42 4C 45 4D 53 20 57 48 45 4E 20 54 41 4C 4B |OBLEMS WHEN TALK|
0000EB30: 49 4E 47 20 54 4F 20 41 20 CB C5 D2 CD C9 D4 20 |ING TO A ...... |
0000EB40: 53 45 52 56 45 52 20 4F 52 20 53 45 4E 44 49 4E |SERVER OR SENDIN|
0000EB50: 47 20 41 20 46 49 4C 45 20 54 4F 20 41 20 CB C5 |G A FILE TO A ..|
0000EB60: D2 CD C9 D4 20 49 4E 0D 52 45 43 45 49 56 45 20 |.... IN.RECEIVE |
0000EB70: 57 41 49 54 2E 20 C9 46 20 53 4F 4D 45 20 54 49 |WAIT. .F SOME TI|
0000EB80: 4D 45 20 48 41 53 20 45 4C 41 50 53 45 44 20 53 |ME HAS ELAPSED S|
0000EB90: 49 4E 43 45 20 41 43 54 49 56 41 54 49 4E 47 20 |INCE ACTIVATING |
0000EBA0: 54 48 45 20 52 45 4D 4F 54 45 20 CB C5 D2 CD C9 |THE REMOTE .....|
0000EBB0: D4 20 41 4E 44 0D 45 53 43 41 50 49 4E 47 20 42 |. AND.ESCAPING B|
0000EBC0: 41 43 4B 20 41 4E 44 20 53 54 41 52 54 49 4E 47 |ACK AND STARTING|
0000EBD0: 20 55 50 20 54 48 45 20 4C 4F 43 41 4C 20 CB C5 | UP THE LOCAL ..|
0000EBE0: D2 CD C9 D4 2C 20 41 20 4E 55 4D 42 45 52 20 4F |...., A NUMBER O|
0000EBF0: 46 20 CE C1 CB 53 20 4D 41 59 20 48 41 56 45 0D |F ...S MAY HAVE.|
0000EC00: 41 43 43 55 4D 55 4C 41 54 45 44 20 49 4E 20 54 |ACCUMULATED IN T|
0000EC10: 48 45 20 4C 4F 43 41 4C 20 CB C5 D2 CD C9 D4 27 |HE LOCAL ......'|
0000EC20: 53 20 49 4E 50 55 54 20 42 55 46 46 45 52 2C 20 |S INPUT BUFFER, |
0000EC30: 53 4F 3A 0D 0D 35 2E 29 20 20 C3 4C 45 41 52 20 |SO:..5.) .LEAR |
0000EC40: 54 48 45 20 49 4E 50 55 54 20 42 55 46 46 45 52 |THE INPUT BUFFER|
0000EC50: 20 41 54 20 54 48 45 20 42 45 47 49 4E 4E 49 4E | AT THE BEGINNIN|
0000EC60: 47 20 4F 46 20 41 20 54 52 41 4E 53 46 45 52 2E |G OF A TRANSFER.|
0000EC70: 0D C9 46 20 54 48 45 20 49 4E 50 55 54 20 42 55 |..F THE INPUT BU|
0000EC80: 46 46 45 52 20 49 53 20 4E 4F 54 20 43 4C 45 41 |FFER IS NOT CLEA|
0000EC90: 52 45 44 2C 20 54 48 45 20 4C 4F 43 41 4C 20 CB |RED, THE LOCAL .|
0000ECA0: C5 D2 CD C9 D4 20 57 49 4C 4C 20 54 48 49 4E 4B |..... WILL THINK|
0000ECB0: 20 54 48 45 20 52 45 4D 4F 54 45 20 53 49 44 45 | THE REMOTE SIDE|
0000ECC0: 0D 49 53 20 48 41 56 49 4E 47 20 54 52 4F 55 42 |.IS HAVING TROUB|
0000ECD0: 4C 45 20 52 45 43 45 49 56 49 4E 47 20 54 48 45 |LE RECEIVING THE|
0000ECE0: 20 46 49 52 53 54 20 50 41 43 4B 45 54 2E 20 20 | FIRST PACKET. |
0000ECF0: C9 4E 20 41 4E 20 45 46 46 4F 52 54 20 54 4F 20 |.N AN EFFORT TO |
0000ED00: 47 45 54 20 54 48 45 20 50 41 43 4B 45 54 0D 54 |GET THE PACKET.T|
0000ED10: 48 52 4F 55 47 48 2C 20 49 54 20 57 49 4C 4C 20 |HROUGH, IT WILL |
0000ED20: 42 45 20 53 45 4E 54 20 41 47 41 49 4E 3B 20 54 |BE SENT AGAIN; T|
0000ED30: 48 49 53 20 52 45 50 45 41 54 53 20 46 4F 52 20 |HIS REPEATS FOR |
0000ED40: 45 56 45 52 59 20 CE C1 CB 20 57 41 49 54 49 4E |EVERY ... WAITIN|
0000ED50: 47 20 49 4E 20 54 48 45 20 49 4E 50 55 54 0D 42 |G IN THE INPUT.B|
0000ED60: 55 46 46 45 52 2E 20 20 C2 59 20 54 48 45 20 54 |UFFER. .Y THE T|
0000ED70: 49 4D 45 20 54 48 45 20 46 49 52 53 54 20 C1 C3 |IME THE FIRST ..|
0000ED80: CB 20 49 53 20 46 49 4E 41 4C 4C 59 20 45 4E 43 |. IS FINALLY ENC|
0000ED90: 4F 55 4E 54 45 52 45 44 20 49 4E 20 54 48 45 20 |OUNTERED IN THE |
0000EDA0: 42 55 46 46 45 52 2C 20 41 0D 4E 55 4D 42 45 52 |BUFFER, A.NUMBER|
0000EDB0: 20 4F 46 20 44 55 50 4C 49 43 41 54 45 53 20 4F | OF DUPLICATES O|
0000EDC0: 46 20 54 48 45 20 46 49 52 53 54 20 50 41 43 4B |F THE FIRST PACK|
0000EDD0: 45 54 20 57 49 4C 4C 20 48 41 56 45 20 42 45 45 |ET WILL HAVE BEE|
0000EDE0: 4E 20 53 45 4E 54 20 4F 55 54 2E 20 20 C9 46 20 |N SENT OUT. .F |
0000EDF0: 54 48 49 53 0D 4E 55 4D 42 45 52 20 45 58 43 45 |THIS.NUMBER EXCE|
0000EE00: 45 44 53 20 54 48 45 20 CE C1 CB 20 54 48 52 45 |EDS THE ... THRE|
0000EE10: 53 48 48 4F 4C 44 2C 20 54 48 45 20 43 4F 4E 4E |SHHOLD, THE CONN|
0000EE20: 45 43 54 49 4F 4E 20 57 49 4C 4C 20 42 45 20 42 |ECTION WILL BE B|
0000EE30: 52 4F 4B 45 4E 2E 20 20 C9 46 20 4E 4F 54 2C 0D |ROKEN. .F NOT,.|
0000EE40: 48 4F 57 45 56 45 52 2C 20 54 48 45 20 53 45 43 |HOWEVER, THE SEC|
0000EE50: 4F 4E 44 20 50 41 43 4B 45 54 20 57 49 4C 4C 20 |OND PACKET WILL |
0000EE60: 42 45 20 52 45 54 52 41 4E 53 4D 49 54 54 45 44 |BE RETRANSMITTED|
0000EE70: 20 4F 4E 43 45 20 46 4F 52 20 45 41 43 48 20 4F | ONCE FOR EACH O|
0000EE80: 46 20 54 48 45 20 45 58 54 52 41 0D C1 C3 CB 53 |F THE EXTRA....S|
0000EE90: 20 54 48 45 20 52 45 4D 4F 54 45 20 CB C5 D2 CD | THE REMOTE ....|
0000EEA0: C9 D4 20 43 4F 52 52 45 43 54 4C 59 20 53 45 4E |.. CORRECTLY SEN|
0000EEB0: 54 20 46 4F 52 20 54 48 45 20 44 55 50 4C 49 43 |T FOR THE DUPLIC|
0000EEC0: 41 54 45 20 46 49 52 53 54 20 50 41 43 4B 45 54 |ATE FIRST PACKET|
0000EED0: 53 2E 20 20 D4 48 49 53 0D 43 41 4E 20 43 4F 4E |S. .HIS.CAN CON|
0000EEE0: 54 49 4E 55 45 20 54 48 52 4F 55 47 48 4F 55 54 |TINUE THROUGHOUT|
0000EEF0: 20 54 48 45 20 46 49 4C 45 20 54 52 41 4E 53 46 | THE FILE TRANSF|
0000EF00: 45 52 2C 20 43 41 55 53 49 4E 47 20 45 41 43 48 |ER, CAUSING EACH|
0000EF10: 20 50 41 43 4B 45 54 20 54 4F 20 42 45 20 53 45 | PACKET TO BE SE|
0000EF20: 4E 54 20 4D 41 4E 59 0D 54 49 4D 45 53 2E 20 20 |NT MANY.TIMES. |
0000EF30: D3 4F 2C 20 49 4E 20 41 44 44 49 54 49 4F 4E 2C |.O, IN ADDITION,|
0000EF40: 0D 0D 36 2E 29 20 20 C3 4C 45 41 52 20 54 48 45 |..6.) .LEAR THE|
0000EF50: 20 49 4E 50 55 54 20 42 55 46 46 45 52 20 41 46 | INPUT BUFFER AF|
0000EF60: 54 45 52 20 52 45 41 44 49 4E 47 20 45 41 43 48 |TER READING EACH|
0000EF70: 20 50 41 43 4B 45 54 2E 0D C1 4E 59 20 43 4F 4D | PACKET...NY COM|
0000EF80: 50 55 54 45 52 20 54 48 41 54 20 42 55 46 46 45 |PUTER THAT BUFFE|
0000EF90: 52 53 20 49 54 53 20 49 4E 50 55 54 20 53 48 4F |RS ITS INPUT SHO|
0000EFA0: 55 4C 44 20 43 4C 45 41 52 20 49 54 53 20 49 4E |ULD CLEAR ITS IN|
0000EFB0: 50 55 54 20 42 55 46 46 45 52 20 42 45 46 4F 52 |PUT BUFFER BEFOR|
0000EFC0: 45 20 54 48 45 0D 54 52 41 4E 53 46 45 52 20 41 |E THE.TRANSFER A|
0000EFD0: 4E 44 20 41 46 54 45 52 20 45 41 43 48 20 50 41 |ND AFTER EACH PA|
0000EFE0: 43 4B 45 54 20 54 48 41 54 20 41 52 52 49 56 45 |CKET THAT ARRIVE|
0000EFF0: 53 20 53 55 43 43 45 53 53 46 55 4C 4C 59 2E 20 |S SUCCESSFULLY. |
0000F000: 20 C2 55 54 20 53 49 4E 43 45 20 4E 4F 54 20 41 | .UT SINCE NOT A|
0000F010: 4C 4C 0D 53 59 53 54 45 4D 53 20 50 52 4F 56 49 |LL.SYSTEMS PROVI|
0000F020: 44 45 20 41 20 43 4C 45 41 52 2D 42 55 46 46 45 |DE A CLEAR-BUFFE|
0000F030: 52 20 46 55 4E 43 54 49 4F 4E 2C 20 57 45 20 4D |R FUNCTION, WE M|
0000F040: 41 59 20 41 44 44 20 41 4E 4F 54 48 45 52 20 52 |AY ADD ANOTHER R|
0000F050: 55 4C 45 3A 0D 0D 37 2E 29 20 20 C4 49 53 43 41 |ULE:..7.) .ISCA|
0000F060: 52 44 20 52 45 44 55 4E 44 41 4E 54 20 C1 C3 CB |RD REDUNDANT ...|
0000F070: 53 2E 0D C9 4E 20 54 48 45 20 53 49 54 55 41 54 |S...N THE SITUAT|
0000F080: 49 4F 4E 20 4A 55 53 54 20 44 45 53 43 52 49 42 |ION JUST DESCRIB|
0000F090: 45 44 2C 20 54 48 45 20 46 49 52 53 54 20 50 41 |ED, THE FIRST PA|
0000F0A0: 43 4B 45 54 20 57 4F 55 4C 44 20 42 45 20 53 45 |CKET WOULD BE SE|
0000F0B0: 4E 54 20 4F 55 54 20 4D 55 4C 54 49 50 4C 45 0D |NT OUT MULTIPLE.|
0000F0C0: 54 49 4D 45 53 2C 20 4F 4E 43 45 20 46 4F 52 20 |TIMES, ONCE FOR |
0000F0D0: 45 41 43 48 20 42 55 46 46 45 52 45 44 20 CE C1 |EACH BUFFERED ..|
0000F0E0: CB 2E 20 20 D5 50 4F 4E 20 52 45 43 45 49 50 54 |.. .PON RECEIPT|
0000F0F0: 20 4F 46 20 54 48 45 20 46 49 52 53 54 20 C1 C3 | OF THE FIRST ..|
0000F100: CB 2C 20 54 48 45 20 53 45 43 4F 4E 44 0D 50 41 |., THE SECOND.PA|
0000F110: 43 4B 45 54 20 57 4F 55 4C 44 20 47 4F 20 4F 55 |CKET WOULD GO OU|
0000F120: 54 2C 20 42 55 54 20 54 48 45 20 4E 45 58 54 20 |T, BUT THE NEXT |
0000F130: 52 45 53 50 4F 4E 53 45 20 57 4F 55 4C 44 20 42 |RESPONSE WOULD B|
0000F140: 45 20 41 4E 4F 54 48 45 52 20 C1 C3 CB 20 46 4F |E ANOTHER ... FO|
0000F150: 52 20 54 48 45 20 46 49 52 53 54 0D 50 41 43 4B |R THE FIRST.PACK|
0000F160: 45 54 3B 20 42 59 20 52 55 4C 45 20 37 2C 20 CB |ET; BY RULE 7, .|
0000F170: C5 D2 CD C9 D4 20 57 4F 55 4C 44 20 53 49 4D 50 |..... WOULD SIMP|
0000F180: 4C 59 20 54 41 4B 45 20 49 4E 20 54 48 45 20 52 |LY TAKE IN THE R|
0000F190: 45 44 55 4E 44 41 4E 54 20 C1 C3 CB 2C 20 49 47 |EDUNDANT ..., IG|
0000F1A0: 4E 4F 52 45 20 49 54 2C 0D 41 4E 44 20 4C 4F 4F |NORE IT,.AND LOO|
0000F1B0: 4B 20 46 4F 52 20 54 48 45 20 4E 45 58 54 20 C1 |K FOR THE NEXT .|
0000F1C0: C3 CB 2C 20 55 4E 54 49 4C 20 49 54 20 47 4F 54 |.., UNTIL IT GOT|
0000F1D0: 20 54 48 45 20 44 45 53 49 52 45 44 20 4F 4E 45 | THE DESIRED ONE|
0000F1E0: 2C 20 49 4E 20 56 49 4F 4C 41 54 49 4F 4E 20 4F |, IN VIOLATION O|
0000F1F0: 46 20 54 48 45 0D 53 50 49 52 49 54 20 4F 46 20 |F THE.SPIRIT OF |
0000F200: D2 55 4C 45 20 31 2E 0D C9 46 20 57 45 20 41 4C |.ULE 1...F WE AL|
0000F210: 4C 4F 57 45 44 20 4F 55 52 53 45 4C 56 45 53 20 |LOWED OURSELVES |
0000F220: 54 4F 20 56 49 4F 4C 41 54 45 20 D2 55 4C 45 20 |TO VIOLATE .ULE |
0000F230: 31 2C 20 57 45 20 43 4F 55 4C 44 20 41 44 44 20 |1, WE COULD ADD |
0000F240: 41 20 46 49 4E 41 4C 20 52 55 4C 45 2C 0D 0D C1 |A FINAL RULE,...|
0000F250: 4E 20 C1 C3 CB 20 46 4F 52 20 50 41 43 4B 45 54 |N ... FOR PACKET|
0000F260: 20 4E 20 41 4C 53 4F 20 C1 C3 CB 53 20 41 4C 4C | N ALSO ...S ALL|
0000F270: 20 50 52 45 56 49 4F 55 53 20 50 41 43 4B 45 54 | PREVIOUS PACKET|
0000F280: 53 2C 20 41 53 20 49 53 20 44 4F 4E 45 20 49 4E |S, AS IS DONE IN|
0000F290: 20 4E 45 54 57 4F 52 4B 0D 50 52 4F 54 4F 43 4F | NETWORK.PROTOCO|
0000F2A0: 4C 53 20 4C 49 4B 45 20 C4 C4 C3 CD D0 2C 20 41 |LS LIKE ....., A|
0000F2B0: 4C 4C 4F 57 49 4E 47 20 44 41 54 41 20 50 41 43 |LLOWING DATA PAC|
0000F2C0: 4B 45 54 53 20 54 4F 20 42 45 20 53 45 4E 54 20 |KETS TO BE SENT |
0000F2D0: 49 4E 20 41 20 43 4F 4E 54 49 4E 55 4F 55 53 20 |IN A CONTINUOUS |
0000F2E0: 53 54 52 45 41 4D 2E 0D CB C5 D2 CD C9 D4 20 43 |STREAM........ C|
0000F2F0: 41 4E 4E 4F 54 20 55 53 45 20 54 48 49 53 20 52 |ANNOT USE THIS R|
0000F300: 55 4C 45 20 46 4F 52 20 4D 41 4E 59 20 52 45 41 |ULE FOR MANY REA|
0000F310: 53 4F 4E 53 3A 20 53 45 51 55 45 4E 43 45 20 4E |SONS: SEQUENCE N|
0000F320: 55 4D 42 45 52 20 57 52 41 50 41 52 4F 55 4E 44 |UMBER WRAPAROUND|
0000F330: 2C 0D 42 55 46 46 45 52 20 4F 56 45 52 46 4C 4F |,.BUFFER OVERFLO|
0000F340: 57 53 2C 20 4C 4F 43 4B 49 4E 47 20 4F 55 54 20 |WS, LOCKING OUT |
0000F350: 48 41 4C 46 20 44 55 50 4C 45 58 20 53 59 53 54 |HALF DUPLEX SYST|
0000F360: 45 4D 53 20 28 48 4F 57 20 43 41 4E 20 54 48 45 |EMS (HOW CAN THE|
0000F370: 59 20 CE C1 CB 20 41 20 42 41 44 0D 50 41 43 4B |Y ... A BAD.PACK|
0000F380: 45 54 20 49 46 20 54 48 45 59 20 43 41 4E 27 54 |ET IF THEY CAN'T|
0000F390: 20 47 45 54 20 43 4F 4E 54 52 4F 4C 20 4F 46 20 | GET CONTROL OF |
0000F3A0: 54 48 45 20 4C 49 4E 45 3F 29 2E 20 20 D4 48 55 |THE LINE?). .HU|
0000F3B0: 53 20 49 46 20 57 45 20 56 49 4F 4C 41 54 45 20 |S IF WE VIOLATE |
0000F3C0: 52 55 4C 45 20 31 2C 0D 49 54 20 4D 55 53 54 20 |RULE 1,.IT MUST |
0000F3D0: 42 45 20 4F 4E 4C 59 20 49 4E 20 41 20 56 45 52 |BE ONLY IN A VER|
0000F3E0: 59 20 4D 49 4E 4F 52 20 57 41 59 2E 0D 0D C5 58 |Y MINOR WAY....X|
0000F3F0: 41 4D 50 4C 45 0D 0D C8 45 52 45 20 49 53 20 41 |AMPLE...ERE IS A|
0000F400: 20 53 45 51 55 45 4E 43 45 20 4F 46 20 50 41 43 | SEQUENCE OF PAC|
0000F410: 4B 45 54 53 20 46 52 4F 4D 20 41 20 52 45 41 4C |KETS FROM A REAL|
0000F420: 20 46 49 4C 45 20 54 52 41 4E 53 46 45 52 2E 20 | FILE TRANSFER. |
0000F430: 20 C5 41 43 48 20 50 41 43 4B 45 54 20 53 54 41 | .ACH PACKET STA|
0000F440: 52 54 53 0D 57 49 54 48 20 C3 4F 4E 54 52 4F 4C |RTS.WITH .ONTROL|
0000F450: 2D C1 2C 20 53 48 4F 57 4E 20 41 53 20 5E C1 2E |-., SHOWN AS ^..|
0000F460: 0D 0D 5E C1 29 20 D3 C8 28 20 40 2D 23 5E 20 20 |..^.) ..( @-#^ |
0000F470: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F480: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F490: 20 D3 45 4E 44 20 C9 4E 49 54 0D 5E C1 29 20 D9 | .END .NIT.^.) .|
0000F4A0: C8 28 20 40 2D 23 25 20 20 20 20 20 20 20 20 20 |.( @-#% |
0000F4B0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F4C0: 20 20 20 20 20 20 20 20 20 20 C1 C3 CB 20 46 4F | ... FO|
0000F4D0: 52 20 D3 45 4E 44 20 C9 4E 49 54 0D 5E C1 2B 21 |R .END .NIT.^.+!|
0000F4E0: C6 CD CF CF CE 2E C4 CF C3 32 20 20 20 20 20 20 |.........2 |
0000F4F0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F500: 20 20 20 20 20 20 20 20 20 20 20 C6 49 4C 45 20 | .ILE |
0000F510: C8 45 41 44 45 52 0D 5E C1 23 21 D9 3F 20 20 20 |.EADER.^.#!.? |
0000F520: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F530: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F540: 20 20 20 20 20 20 C1 C3 CB 20 46 4F 52 20 C6 49 | ... FOR .I|
0000F550: 4C 45 20 C8 45 41 44 45 52 0D 5E C1 C5 22 C4 20 |LE .EADER.^..". |
0000F560: 20 20 CE 4F 20 43 45 4C 45 53 54 49 41 4C 20 42 | .O CELESTIAL B|
0000F570: 4F 44 59 20 48 41 53 20 52 45 51 55 49 52 45 44 |ODY HAS REQUIRED|
0000F580: 20 CA 20 20 20 20 20 20 20 C6 49 52 53 54 20 C4 | . .IRST .|
0000F590: 41 54 41 20 50 41 43 4B 45 54 0D 5E C1 23 22 D9 |ATA PACKET.^.#".|
0000F5A0: 40 40 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |@@ |
0000F5B0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F5C0: 20 20 20 20 20 20 20 20 20 20 C1 C3 CB 20 46 4F | ... FO|
0000F5D0: 52 20 46 49 52 53 54 20 C4 41 54 41 20 50 41 43 |R FIRST .ATA PAC|
0000F5E0: 4B 45 54 0D 5E C1 C5 23 C4 41 53 20 4D 25 25 25 |KET.^..#.AS M%%%|
0000F5F0: 55 43 48 20 4C 41 42 4F 52 20 46 4F 52 20 54 48 |UCH LABOR FOR TH|
0000F600: 45 20 53 54 55 44 59 20 4F 46 20 49 54 53 23 20 |E STUDY OF ITS# |
0000F610: 20 20 20 D3 45 43 4F 4E 44 20 C4 41 54 41 20 50 | .ECOND .ATA P|
0000F620: 41 43 4B 45 54 2C 20 C2 41 44 0D 5E C1 23 23 CE |ACKET, .AD.^.##.|
0000F630: 38 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |8 |
0000F640: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F650: 20 20 20 20 20 20 20 20 20 20 CE C1 CB 20 46 4F | ... FO|
0000F660: 52 20 53 45 43 4F 4E 44 20 C4 41 54 41 20 50 41 |R SECOND .ATA PA|
0000F670: 43 4B 45 54 0D 5E C1 C5 23 C4 41 53 20 4D 55 43 |CKET.^..#.AS MUC|
0000F680: 48 20 4C 41 42 4F 52 20 46 4F 52 20 54 48 45 20 |H LABOR FOR THE |
0000F690: 53 54 55 44 59 20 4F 46 20 49 54 53 23 20 20 20 |STUDY OF ITS# |
0000F6A0: 20 20 20 20 D3 45 43 4F 4E 44 20 C4 41 54 41 20 | .ECOND .ATA |
0000F6B0: 50 41 43 4B 45 54 20 41 47 41 49 4E 0D 5E C1 23 |PACKET AGAIN.^.#|
0000F6C0: 23 D9 C1 20 20 20 20 20 20 20 20 20 20 20 20 20 |#.. |
0000F6D0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F6E0: 20 20 20 20 20 20 20 20 20 20 20 20 C1 C3 CB 20 | ... |
0000F6F0: 46 4F 52 20 53 45 43 4F 4E 44 20 C4 41 54 41 20 |FOR SECOND .ATA |
0000F700: 50 41 43 4B 45 54 0D 5E C1 C5 24 C4 23 CD 23 CA |PACKET.^..$.#.#.|
0000F710: 4D 4F 54 49 4F 4E 20 41 53 20 54 48 45 20 4D 4F |MOTION AS THE MO|
0000F720: 4F 4E 2E 20 20 D3 49 4E 43 45 20 C3 4C 41 C1 20 |ON. .INCE .LA. |
0000F730: 20 20 20 20 20 20 45 54 43 2E 2E 2E 0D 5E C1 23 | ETC....^.#|
0000F740: 24 D9 C2 0D 28 4D 41 4E 59 20 50 41 43 4B 45 54 |$...(MANY PACKET|
0000F750: 53 20 4F 4D 49 54 54 45 44 20 48 45 52 45 29 0D |S OMITTED HERE).|
0000F760: 5E C1 C4 22 C4 4F 55 54 20 33 30 30 20 54 45 52 |^..".OUT 300 TER|
0000F770: 4D 53 20 41 52 45 20 53 55 46 46 49 43 49 45 4E |MS ARE SUFFICIEN|
0000F780: 54 2E 23 CD 23 CA D5 20 20 20 20 20 20 20 20 CC |T.#.#.. .|
0000F790: 41 53 54 20 C4 41 54 41 20 50 41 43 4B 45 54 0D |AST .ATA PACKET.|
0000F7A0: 5E C1 23 22 D9 40 20 20 20 20 20 20 20 20 20 20 |^.#".@ |
0000F7B0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F7C0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 C1 | .|
0000F7D0: C3 CB 20 46 4F 52 20 4C 41 53 54 20 C4 41 54 41 |.. FOR LAST .ATA|
0000F7E0: 0D 5E C1 23 23 DA C2 20 20 20 20 20 20 20 20 20 |.^.##.. |
0000F7F0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F800: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F810: C5 CF C6 0D 5E C1 23 23 D9 C1 20 20 20 20 20 20 |....^.##.. |
0000F820: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F830: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F840: 20 20 20 C1 C3 CB 20 46 4F 52 20 C5 CF C6 0D 5E | ... FOR ....^|
0000F850: C1 23 24 C2 2B 20 20 20 20 20 20 20 20 20 20 20 |.#$.+ |
0000F860: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F870: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 C5 CF | ..|
0000F880: D4 0D 5E C1 23 24 D9 C2 20 20 20 20 20 20 20 20 |..^.#$.. |
0000F890: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F8A0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
0000F8B0: 20 C1 C3 CB 20 46 4F 52 20 C5 CF D4 0D 0D C9 4E | ... FOR ......N|
0000F8C0: 20 54 48 45 20 46 49 52 53 54 20 50 41 43 4B 45 | THE FIRST PACKE|
0000F8D0: 54 2C 20 57 45 20 53 45 45 20 46 4F 4C 4C 4F 57 |T, WE SEE FOLLOW|
0000F8E0: 49 4E 47 20 54 48 45 20 43 4F 4E 54 52 4F 4C 2D |ING THE CONTROL-|
0000F8F0: C1 20 54 48 45 20 50 41 43 4B 45 54 20 4C 45 4E |. THE PACKET LEN|
0000F900: 47 54 48 20 22 29 22 0D 28 34 31 2C 20 4C 45 53 |GTH ")".(41, LES|
0000F910: 53 20 33 32 2C 20 4F 52 20 39 29 2C 20 46 4F 4C |S 32, OR 9), FOL|
0000F920: 4C 4F 57 45 44 20 42 59 20 54 48 45 20 50 41 43 |LOWED BY THE PAC|
0000F930: 4B 45 54 20 54 59 50 45 2C 20 D3 20 28 D3 45 4E |KET TYPE, . (.EN|
0000F940: 44 2D C9 4E 49 54 29 2C 20 46 4F 4C 4C 4F 57 45 |D-.NIT), FOLLOWE|
0000F950: 44 20 42 59 0D 54 48 45 20 41 50 50 52 4F 50 52 |D BY.THE APPROPR|
0000F960: 49 41 54 45 20 50 41 52 41 4D 45 54 45 52 20 44 |IATE PARAMETER D|
0000F970: 45 43 4C 41 52 41 54 49 4F 4E 53 3A 20 4D 41 58 |ECLARATIONS: MAX|
0000F980: 49 4D 55 4D 20 50 41 43 4B 45 54 20 4C 45 4E 47 |IMUM PACKET LENG|
0000F990: 54 48 20 49 53 20 C8 20 28 37 32 2D 33 32 20 3D |TH IS . (72-32 =|
0000F9A0: 0D 34 30 29 2C 20 54 49 4D 45 4F 55 54 20 49 53 |.40), TIMEOUT IS|
0000F9B0: 20 22 28 22 20 28 34 30 2D 33 32 20 3D 20 38 29 | "(" (40-32 = 8)|
0000F9C0: 2C 20 4E 55 4D 42 45 52 20 4F 46 20 50 41 44 44 |, NUMBER OF PADD|
0000F9D0: 49 4E 47 20 43 48 41 52 41 43 54 45 52 53 20 49 |ING CHARACTERS I|
0000F9E0: 53 20 30 20 28 53 50 41 43 45 20 3D 0D 33 32 2D |S 0 (SPACE =.32-|
0000F9F0: 33 32 20 3D 20 30 29 2C 20 54 48 45 20 50 41 44 |32 = 0), THE PAD|
0000FA00: 44 49 4E 47 20 43 48 41 52 41 43 54 45 52 20 49 |DING CHARACTER I|
0000FA10: 53 20 30 2C 20 45 4E 44 2D 4F 46 2D 4C 49 4E 45 |S 0, END-OF-LINE|
0000FA20: 20 49 53 20 22 2D 22 20 28 34 35 2D 33 32 20 3D | IS "-" (45-32 =|
0000FA30: 20 31 33 2C 20 54 48 45 0D C1 D3 C3 C9 C9 20 56 | 13, THE...... V|
0000FA40: 41 4C 55 45 20 4F 46 20 43 41 52 52 49 41 47 45 |ALUE OF CARRIAGE|
0000FA50: 20 52 45 54 55 52 4E 29 2C 20 54 48 45 20 43 4F | RETURN), THE CO|
0000FA60: 4E 54 52 4F 4C 2D 51 55 4F 54 45 20 43 48 41 52 |NTROL-QUOTE CHAR|
0000FA70: 41 43 54 45 52 20 49 53 20 22 23 22 2C 20 41 4E |ACTER IS "#", AN|
0000FA80: 44 20 54 48 45 0D 52 45 4D 41 49 4E 49 4E 47 20 |D THE.REMAINING |
0000FA90: 46 49 45 4C 44 53 20 41 52 45 20 4F 4D 49 54 54 |FIELDS ARE OMITT|
0000FAA0: 45 44 2C 20 44 45 46 41 55 4C 54 49 4E 47 20 54 |ED, DEFAULTING T|
0000FAB0: 4F 20 41 50 50 52 4F 50 52 49 41 54 45 20 56 41 |O APPROPRIATE VA|
0000FAC0: 4C 55 45 53 2E 20 20 D4 48 45 20 46 49 4E 41 4C |LUES. .HE FINAL|
0000FAD0: 0D 43 48 41 52 41 43 54 45 52 20 22 5E 22 20 49 |.CHARACTER "^" I|
0000FAE0: 53 20 54 48 45 20 53 49 4E 47 4C 45 2D 43 48 41 |S THE SINGLE-CHA|
0000FAF0: 52 41 43 54 45 52 20 43 48 45 43 4B 53 55 4D 2C |RACTER CHECKSUM,|
0000FB00: 20 43 4F 4D 50 55 54 45 44 20 41 53 20 46 4F 4C | COMPUTED AS FOL|
0000FB10: 4C 4F 57 53 20 28 41 4C 4C 0D 4E 55 4D 42 45 52 |LOWS (ALL.NUMBER|
0000FB20: 53 20 41 4E 44 20 43 4F 4D 50 55 54 41 54 49 4F |S AND COMPUTATIO|
0000FB30: 4E 53 20 49 4E 20 4F 43 54 41 4C 2C 20 41 4E 44 |NS IN OCTAL, AND|
0000FB40: 20 22 53 50 22 20 52 45 50 52 45 53 45 4E 54 53 | "SP" REPRESENTS|
0000FB50: 20 41 20 53 50 41 43 45 29 3A 0D 0D 29 20 20 20 | A SPACE):..) |
0000FB60: 20 53 50 20 20 20 D3 20 20 20 20 20 C8 20 20 20 | SP . . |
0000FB70: 20 20 28 20 20 20 20 53 50 20 20 20 40 20 20 20 | ( SP @ |
0000FB80: 20 20 2D 20 20 20 20 23 0D 0D 35 31 20 2B 20 34 | - #..51 + 4|
0000FB90: 30 20 2B 20 31 32 33 20 2B 20 31 31 30 20 2B 20 |0 + 123 + 110 + |
0000FBA0: 35 30 20 2B 20 34 30 20 2B 20 31 30 30 20 2B 20 |50 + 40 + 100 + |
0000FBB0: 35 35 20 2B 20 34 33 20 3D 20 36 37 34 0D 0D 36 |55 + 43 = 674..6|
0000FBC0: 37 34 20 2B 20 28 36 37 34 2F 33 30 30 29 20 3D |74 + (674/300) =|
0000FBD0: 20 36 37 36 0D 0D 36 37 36 20 C1 CE C4 20 37 37 | 676..676 ... 77|
0000FBE0: 20 3D 20 37 36 3B 0D 0D 43 48 41 52 28 37 36 29 | = 76;..CHAR(76)|
0000FBF0: 20 3D 20 37 36 2B 34 30 20 3D 20 31 33 36 20 3D | = 76+40 = 136 =|
0000FC00: 20 22 5E 22 0D 0D D4 48 45 20 52 45 43 45 49 56 | "^"...HE RECEIV|
0000FC10: 45 52 20 C1 C3 CB 53 20 57 49 54 48 20 49 54 53 |ER ...S WITH ITS|
0000FC20: 20 4F 57 4E 20 50 41 52 41 4D 45 54 45 52 53 2C | OWN PARAMETERS,|
0000FC30: 20 57 48 49 43 48 20 41 52 45 20 54 48 45 20 53 | WHICH ARE THE S|
0000FC40: 41 4D 45 2E 20 20 D4 48 45 4E 20 43 4F 4D 45 53 |AME. .HEN COMES|
0000FC50: 20 54 48 45 0D 46 49 4C 45 20 48 45 41 44 45 52 | THE.FILE HEADER|
0000FC60: 2C 20 54 48 45 20 46 49 4C 45 2C 20 C5 CF C6 2C |, THE FILE, ...,|
0000FC70: 20 41 4E 44 20 C5 CF D4 2E 20 20 CF 4E 45 20 44 | AND .... .NE D|
0000FC80: 41 54 41 20 50 41 43 4B 45 54 20 57 41 53 20 43 |ATA PACKET WAS C|
0000FC90: 4F 52 52 55 50 54 45 44 20 42 59 20 41 20 42 55 |ORRUPTED BY A BU|
0000FCA0: 52 53 54 0D 4F 46 20 22 25 22 20 43 48 41 52 41 |RST.OF "%" CHARA|
0000FCB0: 43 54 45 52 53 2C 20 CE C1 CB 27 44 2C 20 41 4E |CTERS, ...'D, AN|
0000FCC0: 44 20 52 45 54 52 41 4E 53 4D 49 54 54 45 44 2E |D RETRANSMITTED.|
0000FCD0: 0D 0D 0D D0 45 52 46 4F 52 4D 41 4E 43 45 0D 3D |....ERFORMANCE.=|
0000FCE0: 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 0D 0D C6 4F 52 20 |==========...OR |
0000FCF0: 54 45 58 54 20 46 49 4C 45 53 20 28 44 4F 43 55 |TEXT FILES (DOCU|
0000FD00: 4D 45 4E 54 53 20 4F 52 20 50 52 4F 47 52 41 4D |MENTS OR PROGRAM|
0000FD10: 20 53 4F 55 52 43 45 29 2C 20 41 53 53 55 4D 49 | SOURCE), ASSUMI|
0000FD20: 4E 47 20 41 4E 20 41 56 45 52 41 47 45 20 4C 49 |NG AN AVERAGE LI|
0000FD30: 4E 45 20 4C 45 4E 47 54 48 0D 4F 46 20 34 30 20 |NE LENGTH.OF 40 |
0000FD40: 57 49 54 48 20 4C 49 4E 45 53 20 53 45 50 41 52 |WITH LINES SEPAR|
0000FD50: 41 54 45 44 20 42 59 20 41 20 43 41 52 52 49 41 |ATED BY A CARRIA|
0000FD60: 47 45 2D 52 45 54 55 52 4E 2F 4C 49 4E 45 46 45 |GE-RETURN/LINEFE|
0000FD70: 45 44 20 50 41 49 52 2C 20 54 48 45 20 4F 4E 4C |ED PAIR, THE ONL|
0000FD80: 59 0D 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 43 |Y.CONTROL CHARAC|
0000FD90: 54 45 52 53 20 4E 4F 52 4D 41 4C 4C 59 20 46 4F |TERS NORMALLY FO|
0000FDA0: 55 4E 44 20 49 4E 20 54 48 45 20 54 45 58 54 20 |UND IN THE TEXT |
0000FDB0: 46 49 4C 45 2C 20 57 45 20 53 45 45 20 41 42 4F |FILE, WE SEE ABO|
0000FDC0: 55 54 20 35 25 20 4F 56 45 52 48 45 41 44 0D 46 |UT 5% OVERHEAD.F|
0000FDD0: 4F 52 20 50 52 45 46 49 58 49 4E 47 20 4F 46 20 |OR PREFIXING OF |
0000FDE0: 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 43 54 45 |CONTROL CHARACTE|
0000FDF0: 52 53 2E 20 20 C1 53 53 55 4D 49 4E 47 20 4E 4F |RS. .SSUMING NO|
0000FE00: 20 4C 49 4E 45 20 54 45 52 4D 49 4E 41 54 4F 52 | LINE TERMINATOR|
0000FE10: 53 20 46 4F 52 20 50 41 43 4B 45 54 53 0D 28 41 |S FOR PACKETS.(A|
0000FE20: 4C 54 48 4F 55 47 48 20 4F 4E 45 20 4F 52 20 42 |LTHOUGH ONE OR B|
0000FE30: 4F 54 48 20 53 49 44 45 53 20 4D 41 59 20 52 45 |OTH SIDES MAY RE|
0000FE40: 51 55 49 52 45 20 54 48 45 4D 29 2C 20 4E 4F 20 |QUIRE THEM), NO |
0000FE50: 52 45 54 52 41 4E 53 4D 49 53 53 49 4F 4E 53 20 |RETRANSMISSIONS |
0000FE60: 4F 52 20 54 49 4D 45 4F 55 54 53 2C 0D 41 4E 44 |OR TIMEOUTS,.AND|
0000FE70: 20 4E 4F 20 54 49 4D 45 20 57 41 53 54 45 44 20 | NO TIME WASTED |
0000FE80: 46 4F 52 20 54 48 45 20 4C 49 4E 45 20 54 4F 20 |FOR THE LINE TO |
0000FE90: 54 55 52 4E 20 41 52 4F 55 4E 44 20 42 45 54 57 |TURN AROUND BETW|
0000FEA0: 45 45 4E 20 50 41 43 4B 45 54 20 41 4E 44 20 52 |EEN PACKET AND R|
0000FEB0: 45 53 50 4F 4E 53 45 2C 0D 54 48 45 4E 20 46 4F |ESPONSE,.THEN FO|
0000FEC0: 52 20 41 56 45 52 41 47 45 20 50 41 43 4B 45 54 |R AVERAGE PACKET|
0000FED0: 20 4C 45 4E 47 54 48 20 50 2C 20 55 53 49 4E 47 | LENGTH P, USING|
0000FEE0: 20 41 20 53 49 4E 47 4C 45 2D 43 48 41 52 41 43 | A SINGLE-CHARAC|
0000FEF0: 54 45 52 20 43 48 45 43 4B 53 55 4D 2C 20 54 48 |TER CHECKSUM, TH|
0000FF00: 45 20 CB C5 D2 CD C9 D4 0D 50 52 4F 54 4F 43 4F |E .......PROTOCO|
0000FF10: 4C 20 4F 56 45 52 48 45 41 44 20 43 4F 4E 53 49 |L OVERHEAD CONSI|
0000FF20: 53 54 53 20 4F 46 3A 0D 0D 20 20 35 20 43 4F 4E |STS OF:.. 5 CON|
0000FF30: 54 52 4F 4C 20 46 49 45 4C 44 20 43 48 41 52 41 |TROL FIELD CHARA|
0000FF40: 43 54 45 52 53 20 49 4E 20 54 48 45 20 44 41 54 |CTERS IN THE DAT|
0000FF50: 41 20 50 41 43 4B 45 54 0D 20 20 35 20 43 48 41 |A PACKET. 5 CHA|
0000FF60: 52 41 43 54 45 52 53 20 49 4E 20 54 48 45 20 41 |RACTERS IN THE A|
0000FF70: 43 4B 4E 4F 57 4C 45 44 47 45 4D 45 4E 54 20 50 |CKNOWLEDGEMENT P|
0000FF80: 41 43 4B 45 54 0D 2B 20 30 2E 30 35 20 50 20 46 |ACKET.+ 0.05 P F|
0000FF90: 4F 52 20 43 4F 4E 54 52 4F 4C 20 43 48 41 52 41 |OR CONTROL CHARA|
0000FFA0: 43 54 45 52 20 51 55 4F 54 49 4E 47 0D 0D D4 48 |CTER QUOTING...H|
0000FFB0: 49 53 20 47 49 56 45 53 20 31 30 2F 50 20 2B 20 |IS GIVES 10/P + |
0000FFC0: 30 2E 30 35 20 4F 56 45 52 48 45 41 44 2E 20 20 |0.05 OVERHEAD. |
0000FFD0: C5 2E 47 2E 20 49 46 20 54 48 45 20 50 41 43 4B |..G. IF THE PACK|
0000FFE0: 45 54 20 4C 45 4E 47 54 48 20 49 53 20 34 30 2C |ET LENGTH IS 40,|
0000FFF0: 20 54 48 45 52 45 20 49 53 20 33 30 25 0D 4F 56 | THERE IS 30%.OV|
00010000: 45 52 48 45 41 44 2E 20 20 C9 46 20 50 20 49 53 |ERHEAD. .F P IS|
00010010: 20 39 36 20 28 54 48 45 20 4D 41 58 49 4D 55 4D | 96 (THE MAXIMUM|
00010020: 29 2C 20 54 48 45 52 45 20 49 53 20 41 42 4F 55 |), THERE IS ABOU|
00010030: 54 20 31 35 25 2E 20 20 D4 48 45 53 45 20 46 49 |T 15%. .HESE FI|
00010040: 47 55 52 45 53 20 57 49 4C 4C 0D 56 41 52 59 20 |GURES WILL.VARY |
00010050: 57 49 54 48 20 54 48 45 20 41 56 45 52 41 47 45 |WITH THE AVERAGE|
00010060: 20 4C 49 4E 45 20 4C 45 4E 47 54 48 20 41 4E 44 | LINE LENGTH AND|
00010070: 20 54 48 45 20 46 52 45 51 55 45 4E 43 59 20 4F | THE FREQUENCY O|
00010080: 46 20 4F 54 48 45 52 20 43 4F 4E 54 52 4F 4C 20 |F OTHER CONTROL |
00010090: 43 48 41 52 41 43 54 45 52 53 0D 28 4C 49 4B 45 |CHARACTERS.(LIKE|
000100A0: 20 54 41 42 53 20 41 4E 44 20 46 4F 52 4D 46 45 | TABS AND FORMFE|
000100B0: 45 44 53 29 20 49 4E 20 54 48 45 20 46 49 4C 45 |EDS) IN THE FILE|
000100C0: 2C 20 41 4E 44 20 57 49 4C 4C 20 47 4F 20 55 50 |, AND WILL GO UP|
000100D0: 20 57 49 54 48 20 49 4D 4D 45 44 49 41 54 45 20 | WITH IMMEDIATE |
000100E0: 52 45 54 52 41 4E 53 2D 0D 4D 49 53 53 49 4F 4E |RETRANS-.MISSION|
000100F0: 53 2C 20 41 4E 44 20 57 41 59 20 55 50 20 57 49 |S, AND WAY UP WI|
00010100: 54 48 20 44 45 4C 41 59 45 44 20 52 45 54 52 41 |TH DELAYED RETRA|
00010110: 4E 53 4D 49 53 53 49 4F 4E 53 2E 20 20 C6 4F 52 |NSMISSIONS. .OR|
00010120: 20 42 49 4E 41 52 59 20 46 49 4C 45 53 2C 20 54 | BINARY FILES, T|
00010130: 48 45 0D 51 55 4F 54 49 4E 47 20 4F 56 45 52 48 |HE.QUOTING OVERH|
00010140: 45 41 44 20 57 49 4C 4C 20 42 45 20 48 49 47 48 |EAD WILL BE HIGH|
00010150: 45 52 2E 20 20 C2 55 54 20 54 52 41 4E 53 4D 49 |ER. .UT TRANSMI|
00010160: 53 53 49 4F 4E 20 4F 56 45 52 48 45 41 44 20 43 |SSION OVERHEAD C|
00010170: 41 4E 20 41 4C 53 4F 20 47 4F 20 44 4F 57 4E 0D |AN ALSO GO DOWN.|
00010180: 44 52 41 4D 41 54 49 43 41 4C 4C 59 20 49 46 20 |DRAMATICALLY IF |
00010190: 50 52 45 46 49 58 20 45 4E 43 4F 44 49 4E 47 20 |PREFIX ENCODING |
000101A0: 49 53 20 55 53 45 44 20 46 4F 52 20 52 45 50 45 |IS USED FOR REPE|
000101B0: 41 54 45 44 20 43 48 41 52 41 43 54 45 52 53 2C |ATED CHARACTERS,|
000101C0: 20 44 45 50 45 4E 44 49 4E 47 20 4F 4E 0D 54 48 | DEPENDING ON.TH|
000101D0: 45 20 4E 41 54 55 52 45 20 4F 46 20 54 48 45 20 |E NATURE OF THE |
000101E0: 44 41 54 41 20 28 42 49 4E 41 52 59 20 44 41 54 |DATA (BINARY DAT|
000101F0: 41 20 43 4F 4E 54 41 49 4E 49 4E 47 20 4D 41 4E |A CONTAINING MAN|
00010200: 59 20 5A 45 52 4F 45 53 2C 20 48 49 47 48 4C 59 |Y ZEROES, HIGHLY|
00010210: 20 49 4E 44 45 4E 54 45 44 20 4F 52 0D 43 4F 4C | INDENTED OR.COL|
00010220: 55 4D 4E 41 52 20 44 41 54 41 20 4F 52 20 50 52 |UMNAR DATA OR PR|
00010230: 4F 47 52 41 4D 20 54 45 58 54 20 57 49 4C 4C 20 |OGRAM TEXT WILL |
00010240: 54 45 4E 44 20 54 4F 20 42 45 4E 45 46 49 54 29 |TEND TO BENEFIT)|
00010250: 2E 20 C5 41 43 48 20 46 49 4C 45 20 54 52 41 4E |. .ACH FILE TRAN|
00010260: 53 46 45 52 20 41 4C 53 4F 0D 47 45 54 53 20 41 |SFER ALSO.GETS A|
00010270: 20 46 49 58 45 44 20 4F 56 45 52 48 45 41 44 20 | FIXED OVERHEAD |
00010280: 46 4F 52 20 54 48 45 20 50 52 45 4C 49 4D 49 4E |FOR THE PRELIMIN|
00010290: 41 52 59 20 28 D3 45 4E 44 20 C9 4E 49 54 2C 20 |ARY (.END .NIT, |
000102A0: C6 49 4C 45 20 C8 45 41 44 45 52 29 20 41 4E 44 |.ILE .EADER) AND|
000102B0: 0D 54 45 52 4D 49 4E 41 54 49 4E 47 20 28 C5 CF |.TERMINATING (..|
000102C0: C6 2C 20 C5 CF D4 29 20 50 41 43 4B 45 54 53 2E |., ...) PACKETS.|
000102D0: 0D 0D C9 46 20 54 48 45 20 4D 41 49 4E 46 52 41 |...F THE MAINFRA|
000102E0: 4D 45 20 45 4E 44 20 4F 46 20 41 20 43 4F 4E 4E |ME END OF A CONN|
000102F0: 45 43 54 49 4F 4E 20 49 53 20 48 45 41 56 49 4C |ECTION IS HEAVIL|
00010300: 59 20 4C 4F 41 44 45 44 2C 20 49 54 20 4D 41 59 |Y LOADED, IT MAY|
00010310: 20 54 41 4B 45 0D 43 4F 4E 53 49 44 45 52 41 42 | TAKE.CONSIDERAB|
00010320: 4C 45 20 54 49 4D 45 20 54 4F 20 44 49 47 45 53 |LE TIME TO DIGES|
00010330: 54 20 41 4E 44 20 50 52 4F 43 45 53 53 20 49 4E |T AND PROCESS IN|
00010340: 43 4F 4D 49 4E 47 20 43 48 41 52 41 43 54 45 52 |COMING CHARACTER|
00010350: 53 20 42 45 46 4F 52 45 20 52 45 50 4C 59 49 4E |S BEFORE REPLYIN|
00010360: 47 2E 0D CF 4E 20 48 41 4C 46 20 44 55 50 4C 45 |G...N HALF DUPLE|
00010370: 58 20 4D 41 49 4E 46 52 41 4D 45 53 2C 20 54 48 |X MAINFRAMES, TH|
00010380: 45 52 45 20 4D 41 59 20 42 45 20 41 20 50 41 55 |ERE MAY BE A PAU|
00010390: 53 45 20 42 45 54 57 45 45 4E 20 53 45 4E 44 49 |SE BETWEEN SENDI|
000103A0: 4E 47 20 41 4E 44 20 52 45 43 45 49 56 49 4E 47 |NG AND RECEIVING|
000103B0: 2C 0D 45 56 45 4E 20 49 46 20 54 48 45 20 4C 4F |,.EVEN IF THE LO|
000103C0: 41 44 20 49 53 20 4C 49 47 48 54 3B 20 54 48 49 |AD IS LIGHT; THI|
000103D0: 53 20 4D 49 47 48 54 20 42 45 20 55 53 45 44 20 |S MIGHT BE USED |
000103E0: 54 4F 20 41 44 56 41 4E 54 41 47 45 20 42 59 20 |TO ADVANTAGE BY |
000103F0: 50 52 45 50 41 52 49 4E 47 20 54 48 45 0D 4E 45 |PREPARING THE.NE|
00010400: 58 54 20 50 41 43 4B 45 54 20 49 4E 20 41 44 56 |XT PACKET IN ADV|
00010410: 41 4E 43 45 20 57 48 49 4C 45 20 57 41 49 54 49 |ANCE WHILE WAITI|
00010420: 4E 47 20 46 4F 52 20 54 48 45 20 43 55 52 52 45 |NG FOR THE CURRE|
00010430: 4E 54 20 C1 C3 CB 2E 20 20 C1 4E 4F 54 48 45 52 |NT .... .NOTHER|
00010440: 20 50 52 4F 42 4C 45 4D 20 4D 41 59 0D 4F 43 43 | PROBLEM MAY.OCC|
00010450: 55 52 20 4F 4E 20 48 45 41 56 49 4C 59 20 4C 4F |UR ON HEAVILY LO|
00010460: 41 44 45 44 20 4D 41 49 4E 46 52 41 4D 45 53 20 |ADED MAINFRAMES |
00010470: 2D 20 55 4E 44 45 53 49 52 41 42 4C 45 20 54 49 |- UNDESIRABLE TI|
00010480: 4D 45 4F 55 54 53 2E 20 20 D4 49 4D 45 4F 55 54 |MEOUTS. .IMEOUT|
00010490: 53 20 41 52 45 0D 49 4E 54 45 4E 44 45 44 20 54 |S ARE.INTENDED T|
000104A0: 4F 20 44 45 54 45 43 54 20 4C 4F 53 54 20 50 41 |O DETECT LOST PA|
000104B0: 43 4B 45 54 53 2E 20 20 C1 20 48 45 41 56 49 4C |CKETS. . HEAVIL|
000104C0: 59 20 4C 4F 41 44 45 44 20 53 59 53 54 45 4D 20 |Y LOADED SYSTEM |
000104D0: 4D 41 59 20 54 41 4B 45 20 4C 4F 4E 47 45 52 20 |MAY TAKE LONGER |
000104E0: 54 48 41 4E 0D 54 48 45 20 54 49 4D 45 4F 55 54 |THAN.THE TIMEOUT|
000104F0: 20 49 4E 54 45 52 56 41 4C 20 54 4F 20 53 45 4E | INTERVAL TO SEN|
00010500: 44 20 41 20 50 41 43 4B 45 54 2E 20 20 C6 4F 52 |D A PACKET. .OR|
00010510: 20 54 48 49 53 20 52 45 41 53 4F 4E 2C 20 4D 41 | THIS REASON, MA|
00010520: 49 4E 46 52 41 4D 45 20 CB C5 D2 CD C9 D4 53 0D |INFRAME ......S.|
00010530: 53 48 4F 55 4C 44 20 54 41 4B 45 20 54 48 45 20 |SHOULD TAKE THE |
00010540: 52 45 51 55 45 53 54 45 44 20 54 49 4D 45 4F 55 |REQUESTED TIMEOU|
00010550: 54 20 49 4E 54 45 52 56 41 4C 20 4F 4E 4C 59 20 |T INTERVAL ONLY |
00010560: 41 53 20 41 20 4D 49 4E 49 4D 55 4D 2C 20 41 4E |AS A MINIMUM, AN|
00010570: 44 20 53 48 4F 55 4C 44 20 41 44 4A 55 53 54 0D |D SHOULD ADJUST.|
00010580: 49 54 20 46 4F 52 20 45 41 43 48 20 50 41 43 4B |IT FOR EACH PACK|
00010590: 45 54 20 42 41 53 45 44 20 4F 4E 20 54 48 45 20 |ET BASED ON THE |
000105A0: 43 55 52 52 45 4E 54 20 53 59 53 54 45 4D 20 4C |CURRENT SYSTEM L|
000105B0: 4F 41 44 2C 20 55 50 20 54 4F 20 41 20 52 45 41 |OAD, UP TO A REA|
000105C0: 53 4F 4E 41 42 4C 45 0D 4D 41 58 49 4D 55 4D 2E |SONABLE.MAXIMUM.|
000105D0: 20 CF 4E 20 41 20 4E 4F 49 53 59 20 4C 49 4E 45 | .N A NOISY LINE|
000105E0: 2C 20 54 48 45 52 45 20 49 53 20 41 20 47 52 45 |, THERE IS A GRE|
000105F0: 41 54 45 52 20 4C 49 4B 45 4C 49 48 4F 4F 44 20 |ATER LIKELIHOOD |
00010600: 4F 46 20 43 4F 52 52 55 50 54 45 44 20 50 41 43 |OF CORRUPTED PAC|
00010610: 4B 45 54 53 0D 41 4E 44 20 54 48 45 52 45 46 4F |KETS.AND THEREFO|
00010620: 52 45 20 4F 46 20 52 45 54 52 41 4E 53 4D 49 53 |RE OF RETRANSMIS|
00010630: 53 49 4F 4E 20 4F 56 45 52 48 45 41 44 2E 20 20 |SION OVERHEAD. |
00010640: D0 45 52 46 4F 52 4D 41 4E 43 45 20 4F 4E 20 4E |.ERFORMANCE ON N|
00010650: 4F 49 53 59 20 4C 49 4E 45 53 20 43 41 4E 20 42 |OISY LINES CAN B|
00010660: 45 0D 49 4D 50 52 4F 56 45 44 20 42 59 20 52 45 |E.IMPROVED BY RE|
00010670: 44 55 43 49 4E 47 20 54 48 45 20 50 41 43 4B 45 |DUCING THE PACKE|
00010680: 54 20 4C 45 4E 47 54 48 2C 20 41 4E 44 20 54 48 |T LENGTH, AND TH|
00010690: 55 53 20 54 48 45 20 50 52 4F 42 41 42 49 4C 49 |US THE PROBABILI|
000106A0: 54 59 20 54 48 41 54 20 41 4E 59 0D 50 41 52 54 |TY THAT ANY.PART|
000106B0: 49 43 55 4C 41 52 20 50 41 43 4B 45 54 20 57 49 |ICULAR PACKET WI|
000106C0: 4C 4C 20 42 45 20 43 4F 52 52 55 50 54 45 44 2C |LL BE CORRUPTED,|
000106D0: 20 41 4E 44 20 54 48 45 20 41 4D 4F 55 4E 54 20 | AND THE AMOUNT |
000106E0: 4F 46 20 54 49 4D 45 20 52 45 51 55 49 52 45 44 |OF TIME REQUIRED|
000106F0: 20 54 4F 0D 52 45 54 52 41 4E 53 4D 49 54 20 41 | TO.RETRANSMIT A|
00010700: 20 43 4F 52 52 55 50 54 45 44 20 50 41 43 4B 45 | CORRUPTED PACKE|
00010710: 54 2E 20 20 C1 20 CB C5 D2 CD C9 D4 20 50 52 4F |T. . ...... PRO|
00010720: 47 52 41 4D 20 43 41 4E 20 55 4E 49 4C 41 54 45 |GRAM CAN UNILATE|
00010730: 52 41 4C 4C 59 20 41 44 4A 55 53 54 20 54 48 45 |RALLY ADJUST THE|
00010740: 0D 50 41 43 4B 45 54 20 4C 45 4E 47 54 48 20 41 |.PACKET LENGTH A|
00010750: 43 43 4F 52 44 49 4E 47 20 54 4F 20 54 48 45 20 |CCORDING TO THE |
00010760: 4E 55 4D 42 45 52 20 4F 46 20 52 45 54 52 41 4E |NUMBER OF RETRAN|
00010770: 53 4D 49 53 53 49 4F 4E 53 20 54 48 41 54 20 41 |SMISSIONS THAT A|
00010780: 52 45 20 4F 43 43 55 52 52 49 4E 47 2E 0D D3 48 |RE OCCURRING...H|
00010790: 4F 52 54 20 50 41 43 4B 45 54 53 20 43 55 54 20 |ORT PACKETS CUT |
000107A0: 44 4F 57 4E 20 4F 4E 20 52 45 54 52 41 4E 53 4D |DOWN ON RETRANSM|
000107B0: 49 53 53 49 4F 4E 20 4F 56 45 52 48 45 41 44 2C |ISSION OVERHEAD,|
000107C0: 20 4C 4F 4E 47 20 50 41 43 4B 45 54 53 20 43 55 | LONG PACKETS CU|
000107D0: 54 20 44 4F 57 4E 20 4F 4E 0D 43 48 41 52 41 43 |T DOWN ON.CHARAC|
000107E0: 54 45 52 20 4F 56 45 52 48 45 41 44 2E 0D 0D 0D |TER OVERHEAD....|
000107F0: 22 D5 53 45 52 20 C9 4E 54 45 52 46 41 43 45 22 |".SER .NTERFACE"|
00010800: 0D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D |.===============|
00010810: 3D 0D 0D CB C5 D2 CD C9 D4 20 57 41 53 20 44 45 |=........ WAS DE|
00010820: 53 49 47 4E 45 44 20 46 52 4F 4D 20 41 20 4D 41 |SIGNED FROM A MA|
00010830: 49 4E 46 52 41 4D 45 20 50 45 52 53 50 45 43 54 |INFRAME PERSPECT|
00010840: 49 56 45 2E 20 CC 49 4B 45 20 4D 41 4E 59 20 4D |IVE. .IKE MANY M|
00010850: 41 49 4E 46 52 41 4D 45 20 50 52 4F 47 52 41 4D |AINFRAME PROGRAM|
00010860: 53 2C 0D CB C5 D2 CD C9 D4 20 49 53 53 55 45 53 |S,....... ISSUES|
00010870: 20 41 20 50 52 4F 4D 50 54 2C 20 54 48 45 20 55 | A PROMPT, THE U|
00010880: 53 45 52 20 54 59 50 45 53 20 41 20 43 4F 4D 4D |SER TYPES A COMM|
00010890: 41 4E 44 2C 20 CB C5 D2 CD C9 D4 20 45 58 45 43 |AND, ...... EXEC|
000108A0: 55 54 45 53 20 54 48 45 20 43 4F 4D 4D 41 4E 44 |UTES THE COMMAND|
000108B0: 0D 41 4E 44 20 49 53 53 55 45 53 20 41 4E 4F 54 |.AND ISSUES ANOT|
000108C0: 48 45 52 20 50 52 4F 4D 50 54 2C 20 41 4E 44 20 |HER PROMPT, AND |
000108D0: 53 4F 20 4F 4E 20 55 4E 54 49 4C 20 54 48 45 20 |SO ON UNTIL THE |
000108E0: 55 53 45 52 20 45 58 49 54 53 20 46 52 4F 4D 20 |USER EXITS FROM |
000108F0: 54 48 45 20 50 52 4F 47 52 41 4D 2E 0D CD 55 43 |THE PROGRAM...UC|
00010900: 48 20 43 41 52 45 20 49 53 20 44 45 56 4F 54 45 |H CARE IS DEVOTE|
00010910: 44 20 54 4F 20 54 48 45 20 43 4F 4D 4D 41 4E 44 |D TO THE COMMAND|
00010920: 20 50 41 52 53 45 52 2C 20 45 56 45 4E 20 4F 4E | PARSER, EVEN ON|
00010930: 20 4D 49 43 52 4F 43 4F 4D 50 55 54 45 52 20 56 | MICROCOMPUTER V|
00010940: 45 52 53 49 4F 4E 53 2E 0D D4 48 45 20 47 4F 41 |ERSIONS...HE GOA|
00010950: 4C 20 49 53 20 54 4F 20 50 52 4F 56 49 44 45 20 |L IS TO PROVIDE |
00010960: C5 4E 47 4C 49 53 48 2D 4C 49 4B 45 20 43 4F 4D |.NGLISH-LIKE COM|
00010970: 4D 41 4E 44 53 20 43 4F 4D 50 4F 53 45 44 20 4F |MANDS COMPOSED O|
00010980: 46 20 53 45 51 55 45 4E 43 45 53 20 4F 46 20 4B |F SEQUENCES OF K|
00010990: 45 59 57 4F 52 44 53 0D 4F 52 20 4F 50 45 52 41 |EYWORDS.OR OPERA|
000109A0: 4E 44 53 2C 20 57 49 54 48 20 41 42 42 52 45 56 |NDS, WITH ABBREV|
000109B0: 49 41 54 49 4F 4E 53 20 50 4F 53 53 49 42 4C 45 |IATIONS POSSIBLE|
000109C0: 20 46 4F 52 20 41 4E 59 20 4B 45 59 57 4F 52 44 | FOR ANY KEYWORD|
000109D0: 20 49 4E 20 41 4E 59 20 46 49 45 4C 44 20 44 4F | IN ANY FIELD DO|
000109E0: 57 4E 20 54 4F 0D 54 48 45 20 4D 49 4E 49 4D 55 |WN TO.THE MINIMU|
000109F0: 4D 20 55 4E 49 51 55 45 20 4C 45 4E 47 54 48 2C |M UNIQUE LENGTH,|
00010A00: 20 41 4E 44 20 57 49 54 48 20 22 3F 22 20 48 45 | AND WITH "?" HE|
00010A10: 4C 50 20 41 56 41 49 4C 41 42 4C 45 20 41 54 20 |LP AVAILABLE AT |
00010A20: 41 4E 59 20 50 4F 49 4E 54 20 49 4E 20 41 0D 43 |ANY POINT IN A.C|
00010A30: 4F 4D 4D 41 4E 44 2E 20 20 CE 4F 54 20 41 4C 4C |OMMAND. .OT ALL|
00010A40: 20 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E 53 | IMPLEMENTATIONS|
00010A50: 20 4E 45 45 44 20 46 4F 4C 4C 4F 57 20 54 48 49 | NEED FOLLOW THI|
00010A60: 53 20 4D 4F 44 45 4C 2C 20 42 55 54 20 4D 4F 53 |S MODEL, BUT MOS|
00010A70: 54 20 44 4F 2E 0D 0D D4 48 45 20 42 41 53 49 43 |T DO....HE BASIC|
00010A80: 20 43 4F 4D 4D 41 4E 44 53 20 41 52 45 20 D3 C5 | COMMANDS ARE ..|
00010A90: CE C4 20 41 4E 44 20 D2 C5 C3 C5 C9 D6 C5 2E 20 |.. AND ........ |
00010AA0: 20 D4 48 45 53 45 20 41 4C 4C 4F 57 20 4D 4F 53 | .HESE ALLOW MOS|
00010AB0: 54 20 CB C5 D2 CD C9 D4 53 20 54 4F 20 45 58 43 |T ......S TO EXC|
00010AC0: 48 41 4E 47 45 0D 46 49 4C 45 53 2E 20 20 CF 50 |HANGE.FILES. .P|
00010AD0: 45 52 41 4E 44 53 20 43 41 4E 20 42 45 20 54 48 |ERANDS CAN BE TH|
00010AE0: 45 20 4E 41 4D 45 20 4F 46 20 41 20 53 49 4E 47 |E NAME OF A SING|
00010AF0: 4C 45 20 46 49 4C 45 2C 20 4F 52 20 41 20 46 49 |LE FILE, OR A FI|
00010B00: 4C 45 20 47 52 4F 55 50 20 44 45 53 49 47 4E 41 |LE GROUP DESIGNA|
00010B10: 54 4F 52 0D 28 45 2E 47 2E 20 57 49 54 48 20 22 |TOR.(E.G. WITH "|
00010B20: 57 49 4C 44 43 41 52 44 53 22 29 20 54 4F 20 54 |WILDCARDS") TO T|
00010B30: 52 41 4E 53 4D 49 54 20 4D 55 4C 54 49 50 4C 45 |RANSMIT MULTIPLE|
00010B40: 20 46 49 4C 45 53 20 49 4E 20 41 20 53 49 4E 47 | FILES IN A SING|
00010B50: 4C 45 20 4F 50 45 52 41 54 49 4F 4E 2E 0D C1 4C |LE OPERATION...L|
00010B60: 54 48 4F 55 47 48 20 53 4F 4D 45 20 53 59 53 54 |THOUGH SOME SYST|
00010B70: 45 4D 53 20 4D 41 59 20 4E 4F 54 20 50 52 4F 56 |EMS MAY NOT PROV|
00010B80: 49 44 45 20 57 49 4C 44 43 41 52 44 20 46 49 4C |IDE WILDCARD FIL|
00010B90: 45 20 50 52 4F 43 45 53 53 49 4E 47 2C 20 54 48 |E PROCESSING, TH|
00010BA0: 45 20 CB C5 D2 CD C9 D4 0D 50 52 4F 54 4F 43 4F |E .......PROTOCO|
00010BB0: 4C 20 41 4C 4C 4F 57 53 20 49 54 2E 0D 0D D4 48 |L ALLOWS IT....H|
00010BC0: 45 20 C3 CF CE CE C5 C3 D4 20 43 4F 4D 4D 41 4E |E ....... COMMAN|
00010BD0: 44 20 50 52 4F 56 49 44 45 53 20 54 48 45 20 4D |D PROVIDES THE M|
00010BE0: 45 43 48 41 4E 49 53 4D 20 46 4F 52 20 4C 4F 47 |ECHANISM FOR LOG|
00010BF0: 47 49 4E 47 20 49 4E 20 41 4E 44 20 54 59 50 49 |GING IN AND TYPI|
00010C00: 4E 47 20 43 4F 4D 4D 41 4E 44 53 0D 41 54 20 54 |NG COMMANDS.AT T|
00010C10: 48 45 20 52 45 4D 4F 54 45 20 48 4F 53 54 2C 20 |HE REMOTE HOST, |
00010C20: 57 48 49 43 48 20 49 53 20 4E 45 43 45 53 53 41 |WHICH IS NECESSA|
00010C30: 52 59 20 49 4E 20 4F 52 44 45 52 20 54 4F 20 53 |RY IN ORDER TO S|
00010C40: 54 41 52 54 20 54 48 45 20 CB C5 D2 CD C9 D4 20 |TART THE ...... |
00010C50: 4F 4E 20 54 48 41 54 0D 53 49 44 45 2E 20 D4 48 |ON THAT.SIDE. .H|
00010C60: 45 20 C3 CF CE CE C5 C3 D4 20 46 41 43 49 4C 49 |E ....... FACILI|
00010C70: 54 59 20 50 52 4F 56 49 44 45 53 20 43 48 41 52 |TY PROVIDES CHAR|
00010C80: 41 43 54 45 52 2D 41 54 2D 41 2D 54 49 4D 45 20 |ACTER-AT-A-TIME |
00010C90: 54 52 41 4E 53 4D 49 53 53 49 4F 4E 2C 20 50 41 |TRANSMISSION, PA|
00010CA0: 52 49 54 59 0D 53 45 4C 45 43 54 49 4F 4E 2C 20 |RITY.SELECTION, |
00010CB0: 52 45 4D 4F 54 45 20 4F 52 20 4C 4F 43 41 4C 20 |REMOTE OR LOCAL |
00010CC0: 45 43 48 49 4E 47 2C 20 41 4E 44 20 54 48 45 20 |ECHING, AND THE |
00010CD0: 41 42 49 4C 49 54 59 20 54 4F 20 53 45 4E 44 20 |ABILITY TO SEND |
00010CE0: 41 4E 59 20 43 48 41 52 41 43 54 45 52 2C 0D 49 |ANY CHARACTER,.I|
00010CF0: 4E 43 4C 55 44 49 4E 47 20 54 48 45 20 22 45 53 |NCLUDING THE "ES|
00010D00: 43 41 50 45 20 43 48 41 52 41 43 54 45 52 22 20 |CAPE CHARACTER" |
00010D10: 54 48 41 54 20 4D 55 53 54 20 42 45 20 55 53 45 |THAT MUST BE USE|
00010D20: 44 20 54 4F 20 47 45 54 20 42 41 43 4B 20 54 4F |D TO GET BACK TO|
00010D30: 20 54 48 45 20 4C 4F 43 41 4C 0D CB C5 D2 CD C9 | THE LOCAL......|
00010D40: D4 2E 20 20 C8 4F 57 45 56 45 52 2C 20 54 48 45 |.. .OWEVER, THE|
00010D50: 52 45 20 49 53 20 4E 4F 20 45 52 52 4F 52 20 44 |RE IS NO ERROR D|
00010D60: 45 54 45 43 54 49 4F 4E 20 4F 52 20 43 4F 52 52 |ETECTION OR CORR|
00010D70: 45 43 54 49 4F 4E 20 44 55 52 49 4E 47 20 C3 CF |ECTION DURING ..|
00010D80: CE CE C5 C3 D4 2C 0D 4A 55 53 54 20 41 53 20 54 |.....,.JUST AS T|
00010D90: 48 45 52 45 20 4E 4F 52 4D 41 4C 4C 59 20 49 53 |HERE NORMALLY IS|
00010DA0: 20 4E 4F 4E 45 20 42 45 54 57 45 45 4E 20 41 4E | NONE BETWEEN AN|
00010DB0: 20 4F 52 44 49 4E 41 52 59 20 54 45 52 4D 49 4E | ORDINARY TERMIN|
00010DC0: 41 4C 20 41 4E 44 20 41 20 48 4F 53 54 2E 0D 0D |AL AND A HOST...|
00010DD0: D7 48 45 4E 20 54 57 4F 20 53 59 53 54 45 4D 53 |.HEN TWO SYSTEMS|
00010DE0: 20 41 52 45 20 44 49 53 53 49 4D 49 4C 41 52 2C | ARE DISSIMILAR,|
00010DF0: 20 41 20 D3 C5 D4 20 43 4F 4D 4D 41 4E 44 20 49 | A ... COMMAND I|
00010E00: 53 20 50 52 4F 56 49 44 45 44 20 54 4F 20 41 4C |S PROVIDED TO AL|
00010E10: 4C 4F 57 20 54 48 45 4D 20 54 4F 0D 41 43 43 4F |LOW THEM TO.ACCO|
00010E20: 4D 4D 4F 44 41 54 45 20 45 41 43 48 20 4F 54 48 |MMODATE EACH OTH|
00010E30: 45 52 27 53 20 50 45 43 55 4C 49 41 52 49 54 49 |ER'S PECULIARITI|
00010E40: 45 53 2C 20 46 4F 52 20 49 4E 53 54 41 4E 43 45 |ES, FOR INSTANCE|
00010E50: 20 D3 C5 D4 20 D0 C1 D2 C9 D4 D9 20 CF C4 C4 20 | ... ...... ... |
00010E60: 54 4F 20 41 44 44 0D 4F 44 44 20 50 41 52 49 54 |TO ADD.ODD PARIT|
00010E70: 59 20 54 4F 20 41 4C 4C 20 4F 55 54 42 4F 55 4E |Y TO ALL OUTBOUN|
00010E80: 44 20 43 48 41 52 41 43 54 45 52 53 2C 20 4F 52 |D CHARACTERS, OR|
00010E90: 20 D3 C5 D4 20 CC CF C3 C1 CC 2D C5 C3 C8 CF 20 | ... .....-.... |
00010EA0: 54 4F 20 44 4F 20 4C 4F 43 41 4C 20 45 43 48 4F |TO DO LOCAL ECHO|
00010EB0: 49 4E 47 0D 57 48 45 4E 20 43 4F 4E 4E 45 43 54 |ING.WHEN CONNECT|
00010EC0: 45 44 20 41 53 20 41 20 54 45 52 4D 49 4E 41 4C |ED AS A TERMINAL|
00010ED0: 20 54 4F 20 41 20 48 41 4C 46 20 44 55 50 4C 45 | TO A HALF DUPLE|
00010EE0: 58 20 53 59 53 54 45 4D 2E 20 20 D4 48 45 20 D3 |X SYSTEM. .HE .|
00010EF0: C5 D4 20 43 4F 4D 4D 41 4E 44 20 4D 55 53 54 0D |.. COMMAND MUST.|
00010F00: 53 4F 4D 45 54 49 4D 45 53 20 42 45 20 55 53 45 |SOMETIMES BE USE|
00010F10: 44 20 54 4F 20 53 55 50 50 4C 59 20 49 4E 46 4F |D TO SUPPLY INFO|
00010F20: 52 4D 41 54 49 4F 4E 20 54 4F 20 54 48 45 20 54 |RMATION TO THE T|
00010F30: 41 52 47 45 54 20 53 59 53 54 45 4D 20 4F 4E 20 |ARGET SYSTEM ON |
00010F40: 48 4F 57 20 54 4F 20 53 54 4F 52 45 0D 41 4E 20 |HOW TO STORE.AN |
00010F50: 49 4E 43 4F 4D 49 4E 47 20 46 49 4C 45 20 57 49 |INCOMING FILE WI|
00010F60: 54 48 20 52 45 53 50 45 43 54 20 54 4F 20 42 4C |TH RESPECT TO BL|
00010F70: 4F 43 4B 20 53 49 5A 45 2C 20 42 59 54 45 20 53 |OCK SIZE, BYTE S|
00010F80: 49 5A 45 2C 20 52 45 43 4F 52 44 20 46 4F 52 4D |IZE, RECORD FORM|
00010F90: 41 54 2C 20 52 45 43 4F 52 44 0D 4C 45 4E 47 54 |AT, RECORD.LENGT|
00010FA0: 48 2E 0D 0D CD 4F 53 54 20 CB C5 D2 CD C9 D4 20 |H....OST ...... |
00010FB0: 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E 53 20 |IMPLEMENTATIONS |
00010FC0: 54 41 4B 45 20 53 50 45 43 49 41 4C 20 43 41 52 |TAKE SPECIAL CAR|
00010FD0: 45 20 54 4F 20 52 45 41 53 53 55 52 45 20 54 48 |E TO REASSURE TH|
00010FE0: 45 20 55 53 45 52 20 44 55 52 49 4E 47 20 46 49 |E USER DURING FI|
00010FF0: 4C 45 0D 54 52 41 4E 53 46 45 52 2E 20 20 D4 48 |LE.TRANSFER. .H|
00011000: 45 20 4E 41 4D 45 53 20 4F 46 20 54 48 45 20 46 |E NAMES OF THE F|
00011010: 49 4C 45 53 20 42 45 49 4E 47 20 54 52 41 4E 53 |ILES BEING TRANS|
00011020: 46 45 52 52 45 44 20 41 52 45 20 53 48 4F 57 4E |FERRED ARE SHOWN|
00011030: 2C 20 41 4E 44 20 41 20 44 59 4E 41 4D 49 43 0D |, AND A DYNAMIC.|
00011040: 44 49 53 50 4C 41 59 20 49 53 20 4D 41 44 45 20 |DISPLAY IS MADE |
00011050: 4F 46 20 54 48 45 20 50 41 43 4B 45 54 20 54 52 |OF THE PACKET TR|
00011060: 41 46 46 49 43 2C 20 53 48 4F 57 49 4E 47 20 53 |AFFIC, SHOWING S|
00011070: 55 43 43 45 53 53 46 55 4C 20 54 52 41 4E 53 4D |UCCESSFUL TRANSM|
00011080: 49 53 53 49 4F 4E 20 4F 46 0D 50 41 43 4B 45 54 |ISSION OF.PACKET|
00011090: 53 20 41 53 20 57 45 4C 4C 20 41 53 20 54 49 4D |S AS WELL AS TIM|
000110A0: 45 4F 55 54 53 20 41 4E 44 20 52 45 54 52 41 4E |EOUTS AND RETRAN|
000110B0: 53 4D 49 53 53 49 4F 4E 53 2E 20 20 CD 45 53 53 |SMISSIONS. .ESS|
000110C0: 41 47 45 53 20 41 52 45 20 49 53 53 55 45 44 20 |AGES ARE ISSUED |
000110D0: 57 48 45 4E 20 54 48 45 0D 55 53 45 52 20 43 4F |WHEN THE.USER CO|
000110E0: 4E 4E 45 43 54 53 20 54 4F 20 54 48 45 20 52 45 |NNECTS TO THE RE|
000110F0: 4D 4F 54 45 20 53 59 53 54 45 4D 20 4F 52 20 45 |MOTE SYSTEM OR E|
00011100: 53 43 41 50 45 53 20 42 41 43 4B 20 46 52 4F 4D |SCAPES BACK FROM|
00011110: 20 49 54 2C 20 41 4E 44 20 CB C5 D2 CD C9 D4 20 | IT, AND ...... |
00011120: 50 52 4F 4D 50 54 53 0D 49 44 45 4E 54 49 46 59 |PROMPTS.IDENTIFY|
00011130: 20 54 48 45 20 49 4D 50 4C 45 4D 45 4E 54 41 54 | THE IMPLEMENTAT|
00011140: 49 4F 4E 2E 20 20 C8 45 4C 50 46 55 4C 20 45 52 |ION. .ELPFUL ER|
00011150: 52 4F 52 20 4D 45 53 53 41 47 45 53 20 41 52 45 |ROR MESSAGES ARE|
00011160: 20 44 49 53 50 4C 41 59 45 44 20 57 48 45 4E 0D | DISPLAYED WHEN.|
00011170: 4E 45 43 45 53 53 41 52 59 3B 20 54 48 45 53 45 |NECESSARY; THESE|
00011180: 20 4D 41 59 20 45 4D 41 4E 41 54 45 20 46 52 4F | MAY EMANATE FRO|
00011190: 4D 20 45 49 54 48 45 52 20 54 48 45 20 4C 4F 43 |M EITHER THE LOC|
000111A0: 41 4C 20 4F 52 20 54 48 45 20 52 45 4D 4F 54 45 |AL OR THE REMOTE|
000111B0: 20 53 59 53 54 45 4D 2E 0D D4 48 45 20 46 49 4E | SYSTEM...HE FIN|
000111C0: 41 4C 20 44 49 53 50 4F 53 49 54 49 4F 4E 20 4F |AL DISPOSITION O|
000111D0: 46 20 54 48 45 20 54 52 41 4E 53 46 45 52 20 49 |F THE TRANSFER I|
000111E0: 53 20 43 4C 45 41 52 4C 59 20 53 54 41 54 45 44 |S CLEARLY STATED|
000111F0: 2C 20 43 4F 4D 50 4C 45 54 45 20 4F 52 20 46 41 |, COMPLETE OR FA|
00011200: 49 4C 45 44 2E 0D 0D D4 48 45 20 41 43 54 49 4F |ILED....HE ACTIO|
00011210: 4E 53 20 52 45 51 55 49 52 45 44 20 4F 46 20 54 |NS REQUIRED OF T|
00011220: 48 45 20 CB C5 D2 CD C9 D4 20 55 53 45 52 20 44 |HE ...... USER D|
00011230: 45 50 45 4E 44 20 55 50 4F 4E 20 54 48 45 20 44 |EPEND UPON THE D|
00011240: 45 47 52 45 45 20 54 4F 20 57 48 49 43 48 20 54 |EGREE TO WHICH T|
00011250: 48 45 0D CB C5 D2 CD C9 D4 20 50 52 4F 47 52 41 |HE....... PROGRA|
00011260: 4D 53 20 49 4E 56 4F 4C 56 45 44 20 48 41 56 45 |MS INVOLVED HAVE|
00011270: 20 49 4D 50 4C 45 4D 45 4E 54 45 44 20 54 48 45 | IMPLEMENTED THE|
00011280: 20 53 50 45 43 49 46 49 43 41 54 49 4F 4E 2E 20 | SPECIFICATION. |
00011290: 20 CD 49 4E 49 4D 41 4C 0D 49 4D 50 4C 45 4D 45 | .INIMAL.IMPLEME|
000112A0: 4E 54 41 54 49 4F 4E 53 20 52 45 51 55 49 52 45 |NTATIONS REQUIRE|
000112B0: 20 54 48 41 54 20 54 48 45 20 55 53 45 52 20 43 | THAT THE USER C|
000112C0: 4F 4E 4E 45 43 54 20 54 4F 20 54 48 45 20 52 45 |ONNECT TO THE RE|
000112D0: 4D 4F 54 45 20 48 4F 53 54 2C 20 53 54 41 52 54 |MOTE HOST, START|
000112E0: 20 CB C5 D2 CD C9 D4 0D 54 48 45 52 45 2C 20 49 | .......THERE, I|
000112F0: 53 53 55 45 20 41 20 D3 C5 CE C4 20 28 4F 52 20 |SSUE A .... (OR |
00011300: D2 C5 C3 C5 C9 D6 C5 29 20 43 4F 4D 4D 41 4E 44 |.......) COMMAND|
00011310: 2C 20 45 53 43 41 50 45 20 42 41 43 4B 20 54 4F |, ESCAPE BACK TO|
00011320: 20 54 48 45 20 4C 4F 43 41 4C 20 4D 41 43 48 49 | THE LOCAL MACHI|
00011330: 4E 45 2C 20 41 4E 44 0D 49 53 53 55 45 20 54 48 |NE, AND.ISSUE TH|
00011340: 45 20 43 4F 4D 50 4C 45 4D 45 4E 54 41 52 59 20 |E COMPLEMENTARY |
00011350: D2 C5 C3 C5 C9 D6 C5 20 28 4F 52 20 D3 C5 CE C4 |....... (OR ....|
00011360: 29 20 43 4F 4D 4D 41 4E 44 2E 20 20 C1 4C 4C 20 |) COMMAND. .LL |
00011370: 54 48 49 53 20 4D 55 53 54 20 42 45 20 44 4F 4E |THIS MUST BE DON|
00011380: 45 20 46 4F 52 0D 45 41 43 48 20 54 52 41 4E 53 |E FOR.EACH TRANS|
00011390: 46 45 52 2E 20 20 CD 4F 52 45 20 41 44 56 41 4E |FER. .ORE ADVAN|
000113A0: 43 45 44 20 49 4D 50 4C 45 4D 45 4E 54 41 54 49 |CED IMPLEMENTATI|
000113B0: 4F 4E 53 20 41 4C 4C 4F 57 20 54 48 45 20 52 45 |ONS ALLOW THE RE|
000113C0: 4D 4F 54 45 20 53 49 44 45 20 54 4F 20 52 55 4E |MOTE SIDE TO RUN|
000113D0: 20 41 53 20 41 0D 22 53 45 52 56 45 52 22 20 41 | AS A."SERVER" A|
000113E0: 4E 44 20 54 4F 20 54 41 4B 45 20 41 4C 4C 20 49 |ND TO TAKE ALL I|
000113F0: 54 53 20 49 4E 53 54 52 55 43 54 49 4F 4E 53 20 |TS INSTRUCTIONS |
00011400: 49 4E 20 53 50 45 43 49 41 4C 20 43 4F 4D 4D 41 |IN SPECIAL COMMA|
00011410: 4E 44 20 50 41 43 4B 45 54 53 20 46 52 4F 4D 20 |ND PACKETS FROM |
00011420: 54 48 45 0D 4C 4F 43 41 4C 20 CB C5 D2 CD C9 D4 |THE.LOCAL ......|
00011430: 3B 20 41 4C 4C 20 54 48 41 54 20 49 53 20 52 45 |; ALL THAT IS RE|
00011440: 51 55 49 52 45 44 20 4F 46 20 54 48 45 20 55 53 |QUIRED OF THE US|
00011450: 45 52 20 4F 4E 20 54 48 45 20 52 45 4D 4F 54 45 |ER ON THE REMOTE|
00011460: 20 45 4E 44 20 49 53 20 54 4F 20 43 4F 4E 4E 45 | END IS TO CONNE|
00011470: 43 54 0D 49 4E 49 54 49 41 4C 4C 59 20 49 4E 20 |CT.INITIALLY IN |
00011480: 4F 52 44 45 52 20 54 4F 20 53 54 41 52 54 20 54 |ORDER TO START T|
00011490: 48 45 20 53 45 52 56 45 52 2E 20 20 D4 48 45 20 |HE SERVER. .HE |
000114A0: 53 45 52 56 45 52 20 57 49 4C 4C 20 45 56 45 4E |SERVER WILL EVEN|
000114B0: 20 4C 4F 47 20 49 54 53 45 4C 46 20 4F 55 54 0D | LOG ITSELF OUT.|
000114C0: 55 50 4F 4E 20 43 4F 4D 4D 41 4E 44 20 46 52 4F |UPON COMMAND FRO|
000114D0: 4D 20 54 48 45 20 4C 4F 43 41 4C 20 CB C5 D2 CD |M THE LOCAL ....|
000114E0: C9 D4 2E 20 20 C1 20 4D 49 4E 49 4D 41 4C 20 53 |... . MINIMAL S|
000114F0: 45 52 56 45 52 20 43 41 4E 20 50 52 4F 43 45 53 |ERVER CAN PROCES|
00011500: 53 20 43 4F 4D 4D 41 4E 44 53 20 54 4F 0D 53 45 |S COMMANDS TO.SE|
00011510: 4E 44 20 46 49 4C 45 53 2C 20 52 45 43 45 49 56 |ND FILES, RECEIV|
00011520: 45 20 46 49 4C 45 53 2C 20 41 4E 44 20 53 48 55 |E FILES, AND SHU|
00011530: 54 20 49 54 53 45 4C 46 20 44 4F 57 4E 2E 0D 0D |T ITSELF DOWN...|
00011540: C8 45 52 45 20 49 53 20 41 4E 20 45 58 41 4D 50 |.ERE IS AN EXAMP|
00011550: 4C 45 20 4F 46 20 41 20 53 45 53 53 49 4F 4E 20 |LE OF A SESSION |
00011560: 49 4E 20 57 48 49 43 48 20 54 48 45 20 55 53 45 |IN WHICH THE USE|
00011570: 52 20 4F 46 20 41 4E 20 C9 C2 CD 20 D0 C3 20 47 |R OF AN ... .. G|
00011580: 45 54 53 20 46 49 4C 45 53 20 46 52 4F 4D 0D 41 |ETS FILES FROM.A|
00011590: 20 C4 C5 C3 D3 D9 D3 D4 C5 CD 2D 32 30 2E 20 20 | .........-20. |
000115A0: D4 48 45 20 41 43 54 49 4F 4E 53 20 53 48 4F 57 |.HE ACTIONS SHOW|
000115B0: 4E 20 41 52 45 20 52 45 51 55 49 52 45 44 20 46 |N ARE REQUIRED F|
000115C0: 4F 52 20 4D 49 4E 49 4D 41 4C 20 CB C5 D2 CD C9 |OR MINIMAL .....|
000115D0: D4 20 49 4D 50 4C 45 4D 45 4E 2D 0D 54 41 54 49 |. IMPLEMEN-.TATI|
000115E0: 4F 4E 53 2E 20 20 D4 48 45 20 50 41 52 54 53 20 |ONS. .HE PARTS |
000115F0: 54 48 45 20 55 53 45 52 20 54 59 50 45 53 20 41 |THE USER TYPES A|
00011600: 52 45 20 55 4E 44 45 52 4C 49 4E 45 44 2C 20 43 |RE UNDERLINED, C|
00011610: 4F 4D 4D 45 4E 54 53 20 42 45 47 49 4E 20 57 49 |OMMENTS BEGIN WI|
00011620: 54 48 20 22 21 22 20 4F 52 0D 41 50 50 45 41 52 |TH "!" OR.APPEAR|
00011630: 20 49 4E 20 49 54 41 4C 49 43 53 2E 20 20 C5 56 | IN ITALICS. .V|
00011640: 45 52 59 54 48 49 4E 47 20 45 4C 53 45 20 49 53 |ERYTHING ELSE IS|
00011650: 20 53 59 53 54 45 4D 20 54 59 50 45 4F 55 54 2E | SYSTEM TYPEOUT.|
00011660: 0D 0D 5B 4B 45 52 4D 49 54 5D 20 D2 55 4E 20 CB |..[KERMIT] .UN .|
00011670: 45 52 4D 49 54 20 4F 4E 20 54 48 45 20 D0 C3 2E |ERMIT ON THE ...|
00011680: 0D 0D CB 45 52 4D 49 54 20 D6 31 2E 32 30 0D 0D |...ERMIT .1.20..|
00011690: CB 45 52 4D 49 54 2D 38 36 3E 20 20 20 20 20 20 |.ERMIT-86> |
000116A0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 21 | !|
000116B0: D4 48 49 53 20 49 53 20 54 48 45 20 CB 45 52 4D |.HIS IS THE .ERM|
000116C0: 49 54 20 50 52 4F 4D 50 54 20 46 4F 52 20 54 48 |IT PROMPT FOR TH|
000116D0: 45 20 D0 C3 2E 0D CB 45 52 4D 49 54 2D 38 36 3E |E .....ERMIT-86>|
000116E0: 5B 43 4F 4E 4E 45 43 54 5D 20 20 20 20 20 20 20 |[CONNECT] |
000116F0: 20 20 20 20 20 21 C3 4F 4E 4E 45 43 54 20 54 4F | !.ONNECT TO|
00011700: 20 54 48 45 20 C4 C5 C3 2D 32 30 2E 0D 0D 5B C3 | THE ...-20...[.|
00011710: 4F 4E 4E 45 43 54 49 4E 47 20 54 4F 20 48 4F 53 |ONNECTING TO HOS|
00011720: 54 2E 20 D4 59 50 45 20 C3 D4 D2 CC 2D C3 20 54 |T. .YPE ....-. T|
00011730: 4F 20 52 45 54 55 52 4E 20 54 4F 20 D0 C3 2E 5D |O RETURN TO ...]|
00011740: 0D 0D D9 4F 55 20 41 52 45 20 4E 4F 57 20 43 4F |...OU ARE NOW CO|
00011750: 4E 4E 45 43 54 45 44 20 54 4F 20 54 48 45 20 C4 |NNECTED TO THE .|
00011760: C5 C3 2D 32 30 2E 0D C3 4F 4C 55 4D 42 49 41 20 |..-20...OLUMBIA |
00011770: D5 4E 49 56 45 52 53 49 54 59 20 C3 D5 32 30 C2 |.NIVERSITY ..20.|
00011780: 2E 20 D4 48 45 20 53 59 53 54 45 4D 20 50 52 49 |. .HE SYSTEM PRI|
00011790: 4E 54 53 20 49 54 53 20 48 45 52 41 4C 44 2E 0D |NTS ITS HERALD..|
000117A0: 0D 5B 54 45 52 4D 49 4E 41 4C 20 56 54 35 32 5D |.[TERMINAL VT52]|
000117B0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
000117C0: 21 D3 45 54 20 59 4F 55 52 20 54 45 52 4D 49 4E |!.ET YOUR TERMIN|
000117D0: 41 4C 20 54 59 50 45 20 28 4F 50 54 49 4F 4E 41 |AL TYPE (OPTIONA|
000117E0: 4C 29 2E 0D 5B 4C 4F 47 49 4E 20 4D 59 2D 49 44 |L)..[LOGIN MY-ID|
000117F0: 20 50 41 53 53 57 4F 52 44 5D 20 20 20 20 20 20 | PASSWORD] |
00011800: 20 20 20 21 CC 4F 47 49 4E 20 55 53 49 4E 47 20 | !.OGIN USING |
00011810: 4E 4F 52 4D 41 4C 20 4C 4F 47 49 4E 20 4D 45 54 |NORMAL LOGIN MET|
00011820: 48 4F 44 2E 0D 28 D4 48 45 20 C4 C5 C3 2D 32 30 |HOD..(.HE ...-20|
00011830: 20 50 52 49 4E 54 53 20 56 41 52 49 4F 55 53 20 | PRINTS VARIOUS |
00011840: 4D 45 53 53 41 47 45 53 2E 29 0D 0D 5B 4B 45 52 |MESSAGES.)..[KER|
00011850: 4D 49 54 5D 20 20 20 20 20 20 20 20 20 20 20 20 |MIT] |
00011860: 20 20 20 20 20 20 20 20 20 20 20 21 D2 55 4E 20 | !.UN |
00011870: CB 45 52 4D 49 54 20 4F 4E 20 54 48 45 20 C4 C5 |.ERMIT ON THE ..|
00011880: C3 2D 32 30 2E 0D 0D CB 45 52 4D 49 54 2D 32 30 |.-20....ERMIT-20|
00011890: 3E 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |> |
000118A0: 20 20 20 20 20 20 21 D4 48 49 53 20 49 53 20 CB | !.HIS IS .|
000118B0: 45 52 4D 49 54 2D 32 30 27 53 20 50 52 4F 4D 50 |ERMIT-20'S PROMP|
000118C0: 54 2E 0D CB 45 52 4D 49 54 2D 32 30 3E 5B 53 45 |T...ERMIT-20>[SE|
000118D0: 4E 44 20 2A 2E 46 4F 52 5D 20 20 20 20 20 20 20 |ND *.FOR] |
000118E0: 20 20 21 D3 45 4E 44 20 41 4C 4C 20 C6 CF D2 D4 | !.END ALL ....|
000118F0: D2 C1 CE 20 46 49 4C 45 53 2E 0D 5B 5E 43 5D 20 |... FILES..[^C] |
00011900: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00011910: 20 20 20 20 20 20 20 20 20 20 21 D4 59 50 45 20 | !.YPE |
00011920: 54 48 45 20 45 53 43 41 50 45 20 53 45 51 55 45 |THE ESCAPE SEQUE|
00011930: 4E 43 45 20 54 4F 20 52 45 54 55 52 4E 20 54 4F |NCE TO RETURN TO|
00011940: 20 54 48 45 20 D0 C3 2E 0D 28 C2 41 43 4B 20 41 | THE ....(.ACK A|
00011950: 54 20 D0 C3 2E 29 0D 0D CB 45 52 4D 49 54 2D 38 |T ...)...ERMIT-8|
00011960: 36 3E 5B 52 45 43 45 49 56 45 5D 20 20 20 20 20 |6>[RECEIVE] |
00011970: 20 20 20 20 20 20 20 21 D4 45 4C 4C 20 54 48 45 | !.ELL THE|
00011980: 20 D0 C3 20 46 49 4C 45 53 20 41 52 45 20 43 4F | .. FILES ARE CO|
00011990: 4D 49 4E 47 2E 0D 28 D4 48 45 20 50 52 4F 47 52 |MING..(.HE PROGR|
000119A0: 45 53 53 20 4F 46 20 54 48 45 20 54 52 41 4E 53 |ESS OF THE TRANS|
000119B0: 46 45 52 20 49 53 20 53 48 4F 57 4E 20 43 4F 4E |FER IS SHOWN CON|
000119C0: 54 49 4E 55 4F 55 53 4C 59 20 4F 4E 20 54 48 45 |TINUOUSLY ON THE|
000119D0: 20 53 43 52 45 45 4E 2E 29 0D 0D D4 52 41 4E 53 | SCREEN.)...RANS|
000119E0: 46 45 52 20 C3 4F 4D 50 4C 45 54 45 2E 0D 0D CB |FER .OMPLETE....|
000119F0: 45 52 4D 49 54 2D 38 36 3E 5B 43 4F 4E 4E 45 43 |ERMIT-86>[CONNEC|
00011A00: 54 5D 20 20 20 20 20 20 20 20 20 20 20 20 21 C7 |T] !.|
00011A10: 45 54 20 42 41 43 4B 20 54 4F 20 54 48 45 20 C4 |ET BACK TO THE .|
00011A20: C5 C3 2D 32 30 2E 0D 5B C3 4F 4E 4E 45 43 54 49 |..-20..[.ONNECTI|
00011A30: 4E 47 20 54 4F 20 48 4F 53 54 2E 20 D4 59 50 45 |NG TO HOST. .YPE|
00011A40: 20 C3 D4 D2 CC 2D C3 20 54 4F 20 52 45 54 55 52 | ....-. TO RETUR|
00011A50: 4E 20 54 4F 20 D0 C3 2E 5D 0D 0D CB 45 52 4D 49 |N TO ...]...ERMI|
00011A60: 54 2D 32 30 3E 5B 45 58 49 54 5D 20 20 20 20 20 |T-20>[EXIT] |
00011A70: 20 20 20 20 20 20 20 20 20 20 21 C7 45 54 20 4F | !.ET O|
00011A80: 55 54 20 4F 46 20 CB 45 52 4D 49 54 2D 32 30 2E |UT OF .ERMIT-20.|
00011A90: 0D 0D 4C 4F 47 4F 55 54 20 20 20 20 20 20 20 20 |..LOGOUT |
00011AA0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00011AB0: 20 21 CC 4F 47 4F 55 54 20 46 52 4F 4D 20 54 48 | !.OGOUT FROM TH|
00011AC0: 45 20 C4 C5 C3 2D 32 30 2E 0D 0D CC 4F 47 47 45 |E ...-20....OGGE|
00011AD0: 44 20 4F 55 54 20 CA 4F 42 20 35 35 2C 20 D5 53 |D OUT .OB 55, .S|
00011AE0: 45 52 20 CD D9 2D C9 C4 2C 20 C1 43 43 4F 55 4E |ER ..-.., .CCOUN|
00011AF0: 54 20 CD D9 2D C1 C3 C3 CF D5 CE D4 2C 20 D4 D4 |T ..-......., ..|
00011B00: D9 20 31 34 36 2C 0D 41 54 20 32 34 2D C1 50 52 |. 146,.AT 24-.PR|
00011B10: 2D 38 33 20 31 35 3A 31 38 3A 35 36 2C 20 20 D5 |-83 15:18:56, .|
00011B20: 53 45 44 20 30 3A 30 30 3A 31 37 20 49 4E 20 30 |SED 0:00:17 IN 0|
00011B30: 3A 32 31 3A 35 35 0D 0D 5B 5E 43 5D 20 20 20 20 |:21:55..[^C] |
00011B40: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 | |
00011B50: 20 20 20 20 20 20 20 21 CE 4F 57 20 22 45 53 43 | !.OW "ESC|
00011B60: 41 50 45 22 20 42 41 43 4B 20 54 4F 20 54 48 45 |APE" BACK TO THE|
00011B70: 20 D0 C3 2C 0D 28 C2 41 43 4B 20 41 54 20 D0 C3 | ..,.(.ACK AT ..|
00011B80: 2E 29 0D 0D CB 45 52 4D 49 54 2D 38 36 3E 45 58 |.)...ERMIT-86>EX|
00011B90: 49 54 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |IT |
00011BA0: 20 20 20 21 41 4E 44 20 45 58 49 54 20 46 52 4F | !AND EXIT FRO|
00011BB0: 4D 20 54 48 45 20 D0 C3 27 53 20 CB 45 52 4D 49 |M THE ..'S .ERMI|
00011BC0: 54 2E 0D 0D 0D D4 48 45 20 53 45 53 53 49 4F 4E |T.....HE SESSION|
00011BD0: 20 49 53 20 53 4F 4D 45 57 48 41 54 20 53 49 4D | IS SOMEWHAT SIM|
00011BE0: 50 4C 45 52 20 57 48 45 4E 20 54 48 45 20 52 45 |PLER WHEN THE RE|
00011BF0: 4D 4F 54 45 20 CB C5 D2 CD C9 D4 20 49 53 20 42 |MOTE ...... IS B|
00011C00: 45 49 4E 47 20 52 55 4E 20 41 53 20 41 0D 53 45 |EING RUN AS A.SE|
00011C10: 52 56 45 52 2E 20 20 D4 48 45 20 55 53 45 52 20 |RVER. .HE USER |
00011C20: 4D 55 53 54 20 53 54 49 4C 4C 20 C3 CF CE CE C5 |MUST STILL .....|
00011C30: C3 D4 2C 20 4C 4F 47 20 49 4E 2C 20 41 4E 44 20 |.., LOG IN, AND |
00011C40: 53 54 41 52 54 20 CB C5 D2 CD C9 D4 20 4F 4E 20 |START ...... ON |
00011C50: 54 48 45 20 52 45 4D 4F 54 45 0D 45 4E 44 2C 20 |THE REMOTE.END, |
00011C60: 42 55 54 20 4E 45 45 44 20 4E 45 56 45 52 20 41 |BUT NEED NEVER A|
00011C70: 47 41 49 4E 20 C3 CF CE CE C5 C3 D4 20 54 4F 20 |GAIN ....... TO |
00011C80: 49 53 53 55 45 20 53 55 42 53 45 51 55 45 4E 54 |ISSUE SUBSEQUENT|
00011C90: 20 D3 C5 CE C4 2C 20 D2 C5 C3 C5 C9 D6 C5 2C 20 | ...., ......., |
00011CA0: C5 D8 C9 D4 2C 20 4F 52 0D CC CF C7 CF D5 D4 20 |...., OR....... |
00011CB0: 43 4F 4D 4D 41 4E 44 53 2C 20 45 56 45 4E 20 54 |COMMANDS, EVEN T|
00011CC0: 48 4F 55 47 48 20 4D 41 4E 59 20 54 52 41 4E 53 |HOUGH MANY TRANS|
00011CD0: 41 43 54 49 4F 4E 53 20 4D 41 59 20 54 41 4B 45 |ACTIONS MAY TAKE|
00011CE0: 20 50 4C 41 43 45 2E 20 20 C1 4C 4C 20 41 43 54 | PLACE. .LL ACT|
00011CF0: 49 4F 4E 53 0D 43 41 4E 20 42 45 20 49 4E 49 54 |IONS.CAN BE INIT|
00011D00: 49 41 54 45 44 20 46 52 4F 4D 20 54 48 45 20 D0 |IATED FROM THE .|
00011D10: C3 2E 0D 0D 0D C1 44 56 41 4E 43 45 44 20 C6 45 |......DVANCED .E|
00011D20: 41 54 55 52 45 53 0D 3D 3D 3D 3D 3D 3D 3D 3D 3D |ATURES.=========|
00011D30: 3D 3D 3D 3D 3D 3D 3D 3D 0D 0D C1 4E 20 4F 50 54 |========...N OPT|
00011D40: 49 4F 4E 41 4C 20 46 45 41 54 55 52 45 20 4F 46 |IONAL FEATURE OF|
00011D50: 20 54 48 45 20 CB C5 D2 CD C9 D4 20 50 52 4F 54 | THE ...... PROT|
00011D60: 4F 43 4F 4C 20 49 53 20 41 20 53 50 45 43 49 41 |OCOL IS A SPECIA|
00011D70: 4C 20 50 41 43 4B 45 54 20 44 45 53 49 47 4E 45 |L PACKET DESIGNE|
00011D80: 44 20 54 4F 0D 45 58 50 52 45 53 53 20 54 48 45 |D TO.EXPRESS THE|
00011D90: 20 41 54 54 52 49 42 55 54 45 53 20 4F 46 20 41 | ATTRIBUTES OF A|
00011DA0: 20 46 49 4C 45 20 49 4E 20 41 20 43 4F 4D 50 41 | FILE IN A COMPA|
00011DB0: 43 54 20 41 4E 44 20 47 45 4E 45 52 49 43 20 4D |CT AND GENERIC M|
00011DC0: 41 4E 4E 45 52 2E 20 D4 48 45 20 52 45 43 45 49 |ANNER. .HE RECEI|
00011DD0: 56 45 52 0D 4D 41 59 20 45 49 54 48 45 52 20 41 |VER.MAY EITHER A|
00011DE0: 54 54 45 4D 50 54 20 54 4F 20 55 53 45 20 54 48 |TTEMPT TO USE TH|
00011DF0: 45 20 41 54 54 52 49 42 55 54 45 53 20 54 4F 20 |E ATTRIBUTES TO |
00011E00: 54 48 45 20 49 4E 43 4F 4D 49 4E 47 20 46 49 4C |THE INCOMING FIL|
00011E10: 45 2C 20 4F 52 20 41 52 43 48 49 56 45 20 54 48 |E, OR ARCHIVE TH|
00011E20: 45 4D 0D 46 4F 52 20 4C 41 54 45 52 20 55 53 45 |EM.FOR LATER USE|
00011E30: 2E 20 20 C1 54 54 52 49 42 55 54 45 53 20 49 4E |. .TTRIBUTES IN|
00011E40: 43 4C 55 44 45 20 4E 4F 54 20 4F 4E 4C 59 20 46 |CLUDE NOT ONLY F|
00011E50: 49 4C 45 20 43 48 41 52 41 43 54 45 52 49 53 54 |ILE CHARACTERIST|
00011E60: 49 43 53 20 42 55 54 20 41 4C 53 4F 20 54 48 45 |ICS BUT ALSO THE|
00011E70: 0D 49 4E 54 45 4E 44 45 44 20 44 49 53 50 4F 53 |.INTENDED DISPOS|
00011E80: 49 54 49 4F 4E 20 2D 20 53 54 4F 52 45 2C 20 50 |ITION - STORE, P|
00011E90: 52 49 4E 54 2C 20 53 55 42 4D 49 54 20 46 4F 52 |RINT, SUBMIT FOR|
00011EA0: 20 42 41 54 43 48 20 50 52 4F 43 45 53 53 49 4E | BATCH PROCESSIN|
00011EB0: 47 2C 20 53 45 4E 44 20 41 53 20 4D 41 49 4C 2C |G, SEND AS MAIL,|
00011EC0: 0D 45 54 43 2E 20 20 CF 54 48 45 52 20 4F 50 54 |.ETC. .THER OPT|
00011ED0: 49 4F 4E 41 4C 20 46 45 41 54 55 52 45 53 20 49 |IONAL FEATURES I|
00011EE0: 4E 43 4C 55 44 45 20 4D 45 43 48 41 4E 49 53 4D |NCLUDE MECHANISM|
00011EF0: 53 20 46 4F 52 20 47 52 41 43 45 46 55 4C 4C 59 |S FOR GRACEFULLY|
00011F00: 20 49 4E 54 45 52 52 55 50 54 49 4E 47 2C 0D 44 | INTERRUPTING,.D|
00011F10: 45 4C 41 59 49 4E 47 2C 20 4F 52 20 53 55 53 50 |ELAYING, OR SUSP|
00011F20: 45 4E 44 49 4E 47 20 4F 50 45 52 41 54 49 4F 4E |ENDING OPERATION|
00011F30: 53 20 49 4E 20 50 52 4F 47 52 45 53 53 3B 20 41 |S IN PROGRESS; A|
00011F40: 4C 54 45 52 4E 41 54 45 20 46 4F 52 4D 53 20 4F |LTERNATE FORMS O|
00011F50: 46 20 50 41 43 4B 45 54 20 44 41 54 41 0D 45 4E |F PACKET DATA.EN|
00011F60: 43 4F 44 49 4E 47 3B 20 46 49 4C 45 4E 41 4D 45 |CODING; FILENAME|
00011F70: 20 43 4F 4E 56 45 52 53 49 4F 4E 2C 20 4C 4F 43 | CONVERSION, LOC|
00011F80: 41 4C 20 46 49 4C 45 20 4D 41 4E 41 47 45 4D 45 |AL FILE MANAGEME|
00011F90: 4E 54 2C 20 52 41 57 20 44 41 54 41 20 54 52 41 |NT, RAW DATA TRA|
00011FA0: 4E 53 4D 49 53 53 49 4F 4E 20 41 4E 44 0D 43 41 |NSMISSION AND.CA|
00011FB0: 50 54 55 52 45 3B 20 43 4F 4D 4D 41 4E 44 20 4D |PTURE; COMMAND M|
00011FC0: 41 43 52 4F 20 44 45 46 49 4E 49 54 49 4F 4E 2C |ACRO DEFINITION,|
00011FD0: 20 45 54 43 2E 20 C1 4C 54 48 4F 55 47 48 20 CB | ETC. .LTHOUGH .|
00011FE0: C5 D2 CD C9 D4 20 57 41 53 20 4E 45 56 45 52 20 |..... WAS NEVER |
00011FF0: 49 4E 54 45 4E 44 45 44 20 54 4F 0D 46 55 4C 46 |INTENDED TO.FULF|
00012000: 49 4C 4C 20 54 48 45 20 52 4F 4C 45 20 4F 46 20 |ILL THE ROLE OF |
00012010: 41 20 47 45 4E 45 52 41 4C 20 50 55 52 50 4F 53 |A GENERAL PURPOS|
00012020: 45 20 4E 45 54 57 4F 52 4B 20 53 45 52 56 45 52 |E NETWORK SERVER|
00012030: 2C 20 49 54 53 20 44 45 53 49 47 4E 20 48 41 53 |, ITS DESIGN HAS|
00012040: 20 4D 41 44 45 20 49 54 0D 53 49 4D 50 4C 45 20 | MADE IT.SIMPLE |
00012050: 54 4F 20 41 44 44 20 4E 45 57 20 46 55 4E 43 54 |TO ADD NEW FUNCT|
00012060: 49 4F 4E 53 2E 20 20 C1 20 CB C5 D2 CD C9 D4 20 |IONS. . ...... |
00012070: 53 45 52 56 45 52 20 48 41 53 20 54 48 45 20 41 |SERVER HAS THE A|
00012080: 42 49 4C 49 54 59 20 54 4F 20 41 43 43 45 50 54 |BILITY TO ACCEPT|
00012090: 0D 43 4F 4D 4D 41 4E 44 53 20 49 4E 20 50 41 43 |.COMMANDS IN PAC|
000120A0: 4B 45 54 53 20 46 52 4F 4D 20 41 20 52 45 4D 4F |KETS FROM A REMO|
000120B0: 54 45 20 CB C5 D2 CD C9 D4 2E 0D 0D D4 48 45 20 |TE ..........HE |
000120C0: 42 41 53 49 43 20 43 4F 4D 4D 41 4E 44 53 20 41 |BASIC COMMANDS A|
000120D0: 52 45 20 46 4F 52 20 53 45 4E 44 49 4E 47 20 4F |RE FOR SENDING O|
000120E0: 52 20 46 45 54 43 48 49 4E 47 20 46 49 4C 45 53 |R FETCHING FILES|
000120F0: 20 41 4E 44 20 46 4F 52 20 53 48 55 54 54 49 4E | AND FOR SHUTTIN|
00012100: 47 20 44 4F 57 4E 20 54 48 45 0D 53 45 52 56 45 |G DOWN THE.SERVE|
00012110: 52 2E 20 20 CF 54 48 45 52 20 43 4F 4D 4D 41 4E |R. .THER COMMAN|
00012120: 44 53 20 4D 41 59 20 52 45 51 55 49 52 45 20 44 |DS MAY REQUIRE D|
00012130: 49 53 50 4C 41 59 20 4F 46 20 54 45 58 54 20 41 |ISPLAY OF TEXT A|
00012140: 54 20 54 48 45 20 55 53 45 52 27 53 20 54 45 52 |T THE USER'S TER|
00012150: 4D 49 4E 41 4C 2C 0D 57 48 49 43 48 20 49 53 20 |MINAL,.WHICH IS |
00012160: 43 4F 4E 54 52 4F 4C 4C 45 44 20 42 59 20 54 48 |CONTROLLED BY TH|
00012170: 45 20 4C 4F 43 41 4C 20 CB C5 D2 CD C9 D4 2E 20 |E LOCAL ....... |
00012180: 20 C6 4F 52 20 45 58 41 4D 50 4C 45 2C 20 41 20 | .OR EXAMPLE, A |
00012190: 44 49 52 45 43 54 4F 52 59 20 4C 49 53 54 49 4E |DIRECTORY LISTIN|
000121A0: 47 0D 43 4F 55 4C 44 20 42 45 20 52 45 51 55 45 |G.COULD BE REQUE|
000121B0: 53 54 45 44 3B 20 54 48 45 20 52 45 53 55 4C 54 |STED; THE RESULT|
000121C0: 49 4E 47 20 54 45 58 54 20 49 53 20 53 45 4E 54 |ING TEXT IS SENT|
000121D0: 20 42 41 43 4B 20 54 4F 20 54 48 45 20 4C 4F 43 | BACK TO THE LOC|
000121E0: 41 4C 20 CB C5 D2 CD C9 D4 20 45 58 41 43 54 4C |AL ...... EXACTL|
000121F0: 59 0D 41 53 20 49 46 20 41 20 46 49 4C 45 20 57 |Y.AS IF A FILE W|
00012200: 45 52 45 20 42 45 49 4E 47 20 54 52 41 4E 53 46 |ERE BEING TRANSF|
00012210: 45 52 52 45 44 2C 20 45 58 43 45 50 54 20 54 48 |ERRED, EXCEPT TH|
00012220: 45 20 44 45 53 54 49 4E 41 54 49 4F 4E 20 49 53 |E DESTINATION IS|
00012230: 20 54 48 45 20 55 53 45 52 27 53 0D 53 43 52 45 | THE USER'S.SCRE|
00012240: 45 4E 2C 20 52 41 54 48 45 52 20 54 48 41 4E 20 |EN, RATHER THAN |
00012250: 41 20 44 49 53 4B 20 46 49 4C 45 2E 20 20 28 CF |A DISK FILE. (.|
00012260: 52 20 49 54 20 43 4F 55 4C 44 20 42 45 20 44 49 |R IT COULD BE DI|
00012270: 53 4B 20 46 49 4C 45 20 54 4F 4F 2E 29 20 20 D7 |SK FILE TOO.) .|
00012280: 49 54 48 20 54 48 49 53 0D 41 42 49 4C 49 54 59 |ITH THIS.ABILITY|
00012290: 20 49 4E 20 50 4C 41 43 45 2C 20 49 54 20 49 53 | IN PLACE, IT IS|
000122A0: 20 50 4F 53 53 49 42 4C 45 20 54 4F 20 49 4D 50 | POSSIBLE TO IMP|
000122B0: 4C 45 4D 45 4E 54 20 41 4C 4C 20 53 4F 52 54 53 |LEMENT ALL SORTS|
000122C0: 20 4F 46 20 43 4F 4D 4D 41 4E 44 53 2C 20 46 4F | OF COMMANDS, FO|
000122D0: 52 0D 49 4E 53 54 41 4E 43 45 20 54 4F 20 44 45 |R.INSTANCE TO DE|
000122E0: 4C 45 54 45 20 41 20 46 49 4C 45 2C 20 53 48 4F |LETE A FILE, SHO|
000122F0: 57 20 57 48 4F 27 53 20 4C 4F 47 47 45 44 20 49 |W WHO'S LOGGED I|
00012300: 4E 2C 20 49 4E 51 55 49 52 45 20 41 42 4F 55 54 |N, INQUIRE ABOUT|
00012310: 20 44 49 53 4B 20 53 50 41 43 45 2C 0D 56 45 52 | DISK SPACE,.VER|
00012320: 49 46 59 20 41 43 43 45 53 53 20 54 4F 20 41 20 |IFY ACCESS TO A |
00012330: 44 49 52 45 43 54 4F 52 59 2C 20 53 55 42 4D 49 |DIRECTORY, SUBMI|
00012340: 54 20 42 41 54 43 48 20 4A 4F 42 53 2C 20 53 45 |T BATCH JOBS, SE|
00012350: 4E 44 20 4D 45 53 53 41 47 45 53 2C 20 41 4E 44 |ND MESSAGES, AND|
00012360: 20 53 4F 20 46 4F 52 54 48 2E 0D 0D D4 48 45 20 | SO FORTH....HE |
00012370: 41 42 49 4C 49 54 59 20 4F 46 20 54 48 45 20 CB |ABILITY OF THE .|
00012380: C5 D2 CD C9 D4 20 53 45 52 56 45 52 20 54 4F 20 |..... SERVER TO |
00012390: 50 45 52 46 4F 52 4D 20 48 4F 53 54 20 46 55 4E |PERFORM HOST FUN|
000123A0: 43 54 49 4F 4E 53 20 43 41 4E 20 42 45 20 41 44 |CTIONS CAN BE AD|
000123B0: 44 45 44 20 56 45 52 59 0D 53 49 4D 50 4C 59 20 |DED VERY.SIMPLY |
000123C0: 55 4E 44 45 52 20 43 45 52 54 41 49 4E 20 4F 50 |UNDER CERTAIN OP|
000123D0: 45 52 41 54 49 4E 47 20 53 59 53 54 45 4D 53 2E |ERATING SYSTEMS.|
000123E0: 20 20 C6 4F 52 20 49 4E 53 54 41 4E 43 45 2C 20 | .OR INSTANCE, |
000123F0: 55 4E 44 45 52 20 D5 CE C9 D8 2C 20 CB C5 D2 CD |UNDER ...., ....|
00012400: C9 D4 20 43 41 4E 0D 22 46 4F 52 4B 22 20 41 20 |.. CAN."FORK" A |
00012410: 53 48 45 4C 4C 20 57 49 54 48 20 43 4F 4D 4D 41 |SHELL WITH COMMA|
00012420: 4E 44 53 20 54 4F 20 50 45 52 46 4F 52 4D 20 41 |NDS TO PERFORM A|
00012430: 4E 59 20 46 55 4E 43 54 49 4F 4E 20 50 4F 53 53 |NY FUNCTION POSS|
00012440: 49 42 4C 45 20 55 4E 44 45 52 20 D5 CE C9 D8 2C |IBLE UNDER ....,|
00012450: 0D 52 45 44 49 52 45 43 54 49 4E 47 20 54 48 45 |.REDIRECTING THE|
00012460: 20 53 54 41 4E 44 41 52 44 20 4F 55 54 50 55 54 | STANDARD OUTPUT|
00012470: 20 54 48 52 4F 55 47 48 20 41 20 50 52 4F 43 45 | THROUGH A PROCE|
00012480: 53 53 20 28 CB C5 D2 CD C9 D4 20 49 54 53 45 4C |SS (...... ITSEL|
00012490: 46 29 20 54 48 41 54 0D 45 4E 43 41 50 53 55 4C |F) THAT.ENCAPSUL|
000124A0: 41 54 45 53 20 49 54 20 49 4E 54 4F 20 CB C5 D2 |ATES IT INTO ...|
000124B0: CD C9 D4 20 50 41 43 4B 45 54 53 20 41 4E 44 20 |... PACKETS AND |
000124C0: 53 45 4E 44 53 20 49 54 20 41 4C 4F 4E 47 2E 20 |SENDS IT ALONG. |
000124D0: C1 20 53 45 52 56 45 52 20 57 49 54 48 20 54 48 |. SERVER WITH TH|
000124E0: 45 53 45 0D 43 41 50 41 42 49 4C 49 54 49 45 53 |ESE.CAPABILITIES|
000124F0: 20 43 4F 55 4C 44 20 50 52 4F 56 49 44 45 20 43 | COULD PROVIDE C|
00012500: 4F 4E 56 45 4E 49 45 4E 54 20 41 43 43 45 53 53 |ONVENIENT ACCESS|
00012510: 20 54 4F 20 41 20 54 49 4D 45 53 48 41 52 49 4E | TO A TIMESHARIN|
00012520: 47 20 53 59 53 54 45 4D 20 42 59 20 55 53 45 52 |G SYSTEM BY USER|
00012530: 53 0D 41 54 20 50 45 52 53 4F 4E 41 4C 20 57 4F |S.AT PERSONAL WO|
00012540: 52 4B 53 54 41 54 49 4F 4E 53 2C 20 57 49 54 48 |RKSTATIONS, WITH|
00012550: 4F 55 54 20 52 45 51 55 49 52 49 4E 47 20 54 48 |OUT REQUIRING TH|
00012560: 45 20 55 53 45 52 53 20 54 4F 20 42 45 20 44 49 |E USERS TO BE DI|
00012570: 52 45 43 54 4C 59 20 49 4E 56 4F 4C 56 45 44 0D |RECTLY INVOLVED.|
00012580: 57 49 54 48 20 54 48 45 20 48 4F 53 54 2E 20 20 |WITH THE HOST. |
00012590: C9 46 2C 20 46 4F 52 20 49 4E 53 54 41 4E 43 45 |.F, FOR INSTANCE|
000125A0: 2C 20 57 4F 52 4B 53 54 41 54 49 4F 4E 53 20 48 |, WORKSTATIONS H|
000125B0: 41 44 20 44 45 44 49 43 41 54 45 44 20 43 4F 4E |AD DEDICATED CON|
000125C0: 4E 45 43 54 49 4F 4E 53 20 54 4F 20 41 0D 48 4F |NECTIONS TO A.HO|
000125D0: 53 54 2C 20 41 4E 44 20 54 48 45 20 48 4F 53 54 |ST, AND THE HOST|
000125E0: 20 48 41 44 20 44 45 44 49 43 41 54 45 44 20 CB | HAD DEDICATED .|
000125F0: C5 D2 CD C9 D4 20 53 45 52 56 45 52 53 20 46 4F |..... SERVERS FO|
00012600: 52 20 45 41 43 48 20 53 55 43 48 20 4C 49 4E 45 |R EACH SUCH LINE|
00012610: 2C 20 55 53 45 52 53 20 43 4F 55 4C 44 0D 47 45 |, USERS COULD.GE|
00012620: 54 20 41 43 43 45 53 53 20 54 4F 20 41 4E 44 20 |T ACCESS TO AND |
00012630: 4D 41 4E 41 47 45 20 54 48 45 49 52 20 48 4F 53 |MANAGE THEIR HOS|
00012640: 54 20 46 49 4C 45 53 20 43 4F 4D 50 4C 45 54 45 |T FILES COMPLETE|
00012650: 4C 59 20 42 59 20 43 4F 4D 4D 41 4E 44 53 20 54 |LY BY COMMANDS T|
00012660: 59 50 45 44 20 41 54 20 54 48 45 0D 57 4F 52 4B |YPED AT THE.WORK|
00012670: 53 54 41 54 49 4F 4E 2E 20 20 D4 41 4B 49 4E 47 |STATION. .AKING|
00012680: 20 54 48 49 53 20 49 44 45 41 20 4F 4E 45 20 53 | THIS IDEA ONE S|
00012690: 54 45 50 20 46 55 52 54 48 45 52 2C 20 54 48 45 |TEP FURTHER, THE|
000126A0: 20 57 4F 52 4B 53 54 41 54 49 4F 4E 20 53 59 53 | WORKSTATION SYS|
000126B0: 54 45 4D 0D 53 4F 46 54 57 41 52 45 20 43 4F 55 |TEM.SOFTWARE COU|
000126C0: 4C 44 20 42 45 20 4D 4F 44 49 46 49 45 44 20 54 |LD BE MODIFIED T|
000126D0: 4F 20 4D 41 4B 45 20 54 48 45 20 57 48 4F 4C 45 |O MAKE THE WHOLE|
000126E0: 20 50 52 4F 43 45 53 53 20 54 52 41 4E 53 50 41 | PROCESS TRANSPA|
000126F0: 52 45 4E 54 20 42 59 20 49 4E 43 4F 52 2D 0D 50 |RENT BY INCOR-.P|
00012700: 4F 52 41 54 49 4E 47 20 41 20 CB C5 D2 CD C9 D4 |ORATING A ......|
00012710: 2D 4C 49 4B 45 20 50 52 4F 54 4F 43 4F 4C 20 49 |-LIKE PROTOCOL I|
00012720: 4E 20 49 54 53 20 46 49 4C 45 20 41 43 43 45 53 |N ITS FILE ACCES|
00012730: 53 20 4C 4F 47 49 43 20 2D 20 46 45 54 43 48 49 |S LOGIC - FETCHI|
00012740: 4E 47 20 41 4E 44 20 55 50 2D 0D 44 41 54 49 4E |NG AND UP-.DATIN|
00012750: 47 20 48 4F 53 54 20 46 49 4C 45 53 20 41 53 20 |G HOST FILES AS |
00012760: 4E 45 43 45 53 53 41 52 59 20 42 45 48 49 4E 44 |NECESSARY BEHIND|
00012770: 20 54 48 45 20 55 53 45 52 27 53 20 42 41 43 4B | THE USER'S BACK|
00012780: 2E 20 20 D3 49 4E 43 45 20 54 48 45 20 44 45 4D |. .INCE THE DEM|
00012790: 41 4E 44 53 0D 50 4C 41 43 45 44 20 4F 4E 20 41 |ANDS.PLACED ON A|
000127A0: 20 48 4F 53 54 20 42 59 20 CB C5 D2 CD C9 D4 20 | HOST BY ...... |
000127B0: 41 52 45 20 52 45 4C 41 54 49 56 45 4C 59 20 4D |ARE RELATIVELY M|
000127C0: 4F 44 45 53 54 2C 20 4D 41 4E 59 20 4D 4F 52 45 |ODEST, MANY MORE|
000127D0: 20 53 49 4D 55 4C 54 41 4E 45 4F 55 53 20 55 53 | SIMULTANEOUS US|
000127E0: 45 52 53 0D 43 4F 55 4C 44 20 50 52 4F 42 41 42 |ERS.COULD PROBAB|
000127F0: 4C 59 20 42 45 20 53 45 52 56 49 43 45 44 20 49 |LY BE SERVICED I|
00012800: 4E 20 54 48 49 53 20 57 41 59 2E 20 20 D4 48 49 |N THIS WAY. .HI|
00012810: 53 20 41 50 50 52 4F 41 43 48 20 43 4F 55 4C 44 |S APPROACH COULD|
00012820: 20 42 45 20 41 20 52 45 4C 41 54 49 56 45 4C 59 | BE A RELATIVELY|
00012830: 0D 50 41 49 4E 4C 45 53 53 20 45 4E 54 52 45 45 |.PAINLESS ENTREE|
00012840: 20 49 4E 54 4F 20 54 48 45 20 44 49 53 54 52 49 | INTO THE DISTRI|
00012850: 42 55 54 45 44 2C 20 4E 45 54 57 4F 52 4B 45 44 |BUTED, NETWORKED|
00012860: 20 45 4E 56 49 52 4F 4E 4D 45 4E 54 20 4F 46 20 | ENVIRONMENT OF |
00012870: 54 4F 4D 4F 52 52 4F 57 2E 20 20 D7 48 45 4E 0D |TOMORROW. .HEN.|
00012880: 4C 4F 43 41 4C 20 41 52 45 41 20 4E 45 54 57 4F |LOCAL AREA NETWO|
00012890: 52 4B 20 50 52 4F 54 4F 43 4F 4C 53 20 42 45 43 |RK PROTOCOLS BEC|
000128A0: 4F 4D 45 20 4D 41 54 55 52 45 20 41 4E 44 20 54 |OME MATURE AND T|
000128B0: 48 45 20 48 41 52 44 57 41 52 45 20 45 43 4F 4E |HE HARDWARE ECON|
000128C0: 4F 4D 49 43 41 4C 20 41 4E 44 0D 57 49 44 45 53 |OMICAL AND.WIDES|
000128D0: 50 52 45 41 44 2C 20 CB C5 D2 CD C9 D4 20 43 41 |PREAD, ...... CA|
000128E0: 4E 20 42 45 20 52 45 50 4C 41 43 45 44 20 42 59 |N BE REPLACED BY|
000128F0: 20 22 54 48 45 20 52 45 41 4C 20 54 48 49 4E 47 | "THE REAL THING|
00012900: 22 2E 20 20 C2 55 54 20 46 4F 52 20 54 48 45 20 |". .UT FOR THE |
00012910: 4F 52 44 49 4E 41 52 59 0D 43 4F 4D 50 55 54 45 |ORDINARY.COMPUTE|
00012920: 52 20 55 53 45 52 20 46 4F 52 20 57 48 4F 4D 20 |R USER FOR WHOM |
00012930: 44 45 44 49 43 41 54 45 44 20 43 4F 4E 4E 45 43 |DEDICATED CONNEC|
00012940: 54 49 4F 4E 53 20 41 52 45 20 49 4D 50 52 41 43 |TIONS ARE IMPRAC|
00012950: 54 49 43 41 4C 2C 20 22 44 4F 2D 49 54 2D 59 4F |TICAL, "DO-IT-YO|
00012960: 55 52 53 45 4C 46 22 0D CB C5 D2 CD C9 D4 2C 20 |URSELF"......., |
00012970: 4F 52 20 53 4F 4D 45 20 46 41 43 49 4C 49 54 59 |OR SOME FACILITY|
00012980: 20 4C 49 4B 45 20 49 54 2C 20 57 49 4C 4C 20 42 | LIKE IT, WILL B|
00012990: 45 20 41 20 56 41 4C 55 41 42 4C 45 20 54 4F 4F |E A VALUABLE TOO|
000129A0: 4C 20 46 4F 52 20 59 45 41 52 53 20 54 4F 20 43 |L FOR YEARS TO C|
000129B0: 4F 4D 45 2E 0D 0D 0D C3 4F 4E 43 4C 55 53 49 4F |OME.....ONCLUSIO|
000129C0: 4E 0D 3D 3D 3D 3D 3D 3D 3D 3D 3D 3D 0D 0D D4 48 |N.==========...H|
000129D0: 45 20 4E 45 45 44 20 46 4F 52 20 41 20 43 48 45 |E NEED FOR A CHE|
000129E0: 41 50 2C 20 43 4F 4E 56 45 4E 49 45 4E 54 20 46 |AP, CONVENIENT F|
000129F0: 49 4C 45 20 54 52 41 4E 53 46 45 52 20 43 41 50 |ILE TRANSFER CAP|
00012A00: 41 42 49 4C 49 54 59 20 41 4D 4F 4E 47 20 44 49 |ABILITY AMONG DI|
00012A10: 56 45 52 53 45 20 53 59 53 54 45 4D 53 0D 49 53 |VERSE SYSTEMS.IS|
00012A20: 20 50 52 45 53 53 49 4E 47 2C 20 41 4E 44 20 54 | PRESSING, AND T|
00012A30: 48 45 52 45 20 41 52 45 20 43 45 52 54 41 49 4E |HERE ARE CERTAIN|
00012A40: 4C 59 20 4D 41 4E 59 20 45 46 46 4F 52 54 53 20 |LY MANY EFFORTS |
00012A50: 53 49 4D 49 4C 41 52 20 54 4F 20 4F 55 52 53 20 |SIMILAR TO OURS |
00012A60: 55 4E 44 45 52 20 57 41 59 20 41 54 0D 4D 41 4E |UNDER WAY AT.MAN|
00012A70: 59 20 50 4C 41 43 45 53 2E 20 20 D7 45 20 48 4F |Y PLACES. .E HO|
00012A80: 50 45 20 54 48 41 54 20 54 48 49 53 20 41 52 54 |PE THAT THIS ART|
00012A90: 49 43 4C 45 20 4D 41 59 20 43 4F 4E 54 52 49 42 |ICLE MAY CONTRIB|
00012AA0: 55 54 45 20 54 4F 20 54 48 4F 53 45 20 45 46 46 |UTE TO THOSE EFF|
00012AB0: 4F 52 54 53 3B 20 57 45 0D 44 4F 4E 27 54 20 43 |ORTS; WE.DON'T C|
00012AC0: 4C 41 49 4D 20 54 4F 20 48 41 56 45 20 54 48 45 |LAIM TO HAVE THE|
00012AD0: 20 4C 41 53 54 20 57 4F 52 44 20 4F 4E 20 41 4E | LAST WORD ON AN|
00012AE0: 59 20 4F 46 20 54 48 45 20 49 53 53 55 45 53 20 |Y OF THE ISSUES |
00012AF0: 52 41 49 53 45 44 20 48 45 52 45 2C 20 41 4E 44 |RAISED HERE, AND|
00012B00: 20 45 58 50 45 43 54 0D 54 48 41 54 20 54 48 49 | EXPECT.THAT THI|
00012B10: 53 20 41 52 54 49 43 4C 45 20 4D 41 59 20 46 4C |S ARTICLE MAY FL|
00012B20: 55 53 48 20 53 4F 4D 45 20 4F 54 48 45 52 20 41 |USH SOME OTHER A|
00012B30: 50 50 52 4F 41 43 48 45 53 20 4F 55 54 20 4F 46 |PPROACHES OUT OF|
00012B40: 20 54 48 45 20 57 4F 4F 44 57 4F 52 4B 2E 20 20 | THE WOODWORK. |
00012B50: D7 45 20 48 41 56 45 0D 42 49 4C 4C 45 44 20 CB |.E HAVE.BILLED .|
00012B60: C5 D2 CD C9 D4 20 41 53 20 41 20 22 53 49 4D 50 |..... AS A "SIMP|
00012B70: 4C 45 22 20 50 52 4F 54 4F 43 4F 4C 3B 20 41 4E |LE" PROTOCOL; AN|
00012B80: 59 4F 4E 45 20 57 48 4F 20 48 41 53 20 52 45 41 |YONE WHO HAS REA|
00012B90: 44 20 54 48 49 53 20 46 41 52 20 57 49 4C 4C 20 |D THIS FAR WILL |
00012BA0: 42 45 47 49 4E 0D 54 4F 20 41 50 50 52 45 43 49 |BEGIN.TO APPRECI|
00012BB0: 41 54 45 20 57 48 41 54 20 4D 55 53 54 20 47 4F |ATE WHAT MUST GO|
00012BC0: 20 49 4E 54 4F 20 54 48 45 20 4D 4F 52 45 20 43 | INTO THE MORE C|
00012BD0: 4F 4D 50 4C 49 43 41 54 45 44 20 50 52 4F 54 4F |OMPLICATED PROTO|
00012BE0: 43 4F 4C 53 20 55 53 45 44 20 49 4E 20 52 45 41 |COLS USED IN REA|
00012BF0: 4C 0D 4E 45 54 57 4F 52 4B 53 2C 20 4F 52 20 57 |L.NETWORKS, OR W|
00012C00: 48 45 4E 20 22 49 4E 54 45 47 52 41 54 49 4F 4E |HEN "INTEGRATION|
00012C10: 22 20 4F 46 20 4D 49 43 52 4F 20 41 4E 44 20 4D |" OF MICRO AND M|
00012C20: 41 49 4E 46 52 41 4D 45 20 49 53 20 41 20 4D 41 |AINFRAME IS A MA|
00012C30: 4A 4F 52 20 47 4F 41 4C 20 2D 20 44 45 4D 41 4E |JOR GOAL - DEMAN|
00012C40: 44 0D 50 41 47 49 4E 47 20 4F 46 20 52 45 4D 4F |D.PAGING OF REMO|
00012C50: 54 45 20 46 49 4C 45 53 2C 20 52 45 4D 4F 54 45 |TE FILES, REMOTE|
00012C60: 20 44 41 54 41 42 41 53 45 20 51 55 45 52 49 45 | DATABASE QUERIE|
00012C70: 53 2C 20 44 49 53 54 52 49 42 55 54 45 44 20 45 |S, DISTRIBUTED E|
00012C80: 44 49 54 49 4E 47 20 41 4E 44 0D 43 4F 4D 50 55 |DITING AND.COMPU|
00012C90: 54 41 54 49 4F 4E 2E 20 CD 45 41 4E 57 48 49 4C |TATION. .EANWHIL|
00012CA0: 45 2C 20 54 48 45 20 CB C5 D2 CD C9 D4 20 50 52 |E, THE ...... PR|
00012CB0: 4F 54 4F 43 4F 4C 20 48 41 53 20 42 45 45 4E 20 |OTOCOL HAS BEEN |
00012CC0: 50 52 4F 56 45 4E 20 53 55 43 43 45 53 53 46 55 |PROVEN SUCCESSFU|
00012CD0: 4C 2C 20 41 4E 44 0D 43 4F 4E 54 49 4E 55 45 53 |L, AND.CONTINUES|
00012CE0: 20 54 4F 20 47 52 4F 57 20 49 4E 20 50 4F 50 55 | TO GROW IN POPU|
00012CF0: 4C 41 52 49 54 59 2E 20 20 C1 53 20 4F 46 20 54 |LARITY. .S OF T|
00012D00: 48 49 53 20 57 52 49 54 49 4E 47 2C 20 49 4D 50 |HIS WRITING, IMP|
00012D10: 4C 45 4D 45 4E 54 41 54 49 4F 4E 53 20 45 58 49 |LEMENTATIONS EXI|
00012D20: 53 54 20 46 4F 52 0D 4D 4F 52 45 20 54 48 41 4E |ST FOR.MORE THAN|
00012D30: 20 35 30 20 43 4F 4D 50 55 54 45 52 20 53 59 53 | 50 COMPUTER SYS|
00012D40: 54 45 4D 53 2E 20 20 D3 4F 4D 45 20 4F 46 20 54 |TEMS. .OME OF T|
00012D50: 48 45 20 4D 41 4A 4F 52 20 4F 4E 45 53 20 49 4E |HE MAJOR ONES IN|
00012D60: 43 4C 55 44 45 3A 0D 0D CD 41 43 48 49 4E 45 20 |CLUDE:...ACHINE |
00012D70: 20 20 20 20 20 20 20 20 20 20 20 CF 50 45 52 41 | .PERA|
00012D80: 54 49 4E 47 20 D3 59 53 54 45 4D 20 20 20 20 20 |TING .YSTEM |
00012D90: 20 20 20 CC 41 4E 47 55 41 47 45 0D 0D C4 C5 C3 | .ANGUAGE.....|
00012DA0: 53 59 53 54 45 4D 2D 31 30 20 20 20 20 20 20 20 |SYSTEM-10 |
00012DB0: 20 20 20 D4 CF D0 D3 2D 31 30 20 20 20 20 20 20 | ....-10 |
00012DC0: 20 20 20 20 20 20 20 20 CD C1 C3 D2 CF 2D 31 30 | .....-10|
00012DD0: 0D C4 C5 C3 D3 D9 D3 D4 C5 CD 2D 32 30 20 20 20 |..........-20 |
00012DE0: 20 20 20 20 20 20 20 D4 CF D0 D3 2D 32 30 20 20 | ....-20 |
00012DF0: 20 20 20 20 20 20 20 20 20 20 20 20 CD C1 C3 D2 | ....|
00012E00: CF 2D 32 30 0D C9 C2 CD 20 33 37 30 20 D3 45 52 |.-20.... 370 .ER|
00012E10: 49 45 53 20 20 20 20 20 20 20 20 D6 CD 2F C3 CD |IES ../..|
00012E20: D3 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 |. |
00012E30: C9 C2 CD 20 C1 53 53 45 4D 42 4C 45 52 0D D6 C1 |... .SSEMBLER...|
00012E40: D8 2D 31 31 20 20 20 20 20 20 20 20 20 20 20 20 |.-11 |
00012E50: 20 20 20 20 D6 CD D3 20 20 20 20 20 20 20 20 20 | ... |
00012E60: 20 20 20 20 20 20 20 20 20 C2 4C 49 53 53 2D 33 | .LISS-3|
00012E70: 32 0D D6 C1 D8 2C D3 D5 CE 2C D0 C4 D0 2D 31 31 |2....,...,...-11|
00012E80: 2C 45 54 43 2E 20 20 20 D5 CE C9 D8 20 20 20 20 |,ETC. .... |
00012E90: 20 20 20 20 20 20 20 20 20 20 20 20 20 C3 0D D0 | ...|
00012EA0: C4 D0 2D 31 31 20 20 20 20 20 20 20 20 20 20 20 |..-11 |
00012EB0: 20 20 20 20 20 D2 D4 2D 31 31 2C D2 D3 D8 2C D2 | ..-11,...,.|
00012EC0: D3 D4 D3 20 20 20 20 20 20 20 CD C1 C3 D2 CF 2D |... .....-|
00012ED0: 31 31 0D 38 30 38 30 2C 38 30 38 35 2C 4F 52 20 |11.8080,8085,OR |
00012EE0: DA 38 30 20 20 20 20 20 20 C3 D0 2F CD 20 20 20 |.80 ../. |
00012EF0: 20 20 20 20 20 20 20 20 20 20 20 20 20 20 38 30 | 80|
00012F00: 38 30 20 C1 D3 CD 0D 38 30 38 36 2C 38 30 38 38 |80 ....8086,8088|
00012F10: 20 20 20 20 20 20 20 20 20 20 20 20 20 D0 C3 20 | .. |
00012F20: C4 CF D3 2C CD D3 20 C4 CF D3 40 20 20 20 20 20 |...,.. ...@ |
00012F30: 20 20 C9 C2 CD 20 D0 C3 20 C1 53 53 45 4D 42 4C | ... .. .SSEMBL|
00012F40: 45 52 0D C1 50 50 4C 45 20 C9 C9 20 36 35 30 32 |ER..PPLE .. 6502|
00012F50: 20 20 20 20 20 20 20 20 20 C1 50 50 4C 45 20 C4 | .PPLE .|
00012F60: CF D3 20 20 20 20 20 20 20 20 20 20 20 20 C4 C5 |.. ..|
00012F70: C3 2D 31 30 2F 32 30 20 C3 D2 CF D3 D3 0D 0D D3 |.-10/20 ........|
00012F80: 4F 4D 45 20 4F 46 20 54 48 45 53 45 20 48 41 56 |OME OF THESE HAV|
00012F90: 45 20 42 45 45 4E 20 43 4F 4E 54 52 49 42 55 54 |E BEEN CONTRIBUT|
00012FA0: 45 44 20 4F 52 20 45 4E 48 41 4E 43 45 44 20 42 |ED OR ENHANCED B|
00012FB0: 59 20 54 48 45 20 49 4E 53 54 49 54 55 54 49 4F |Y THE INSTITUTIO|
00012FC0: 4E 53 20 4C 49 53 54 45 44 20 49 4E 0D 54 48 45 |NS LISTED IN.THE|
00012FD0: 20 41 43 4B 4E 4F 57 4C 45 44 47 45 4D 45 4E 54 | ACKNOWLEDGEMENT|
00012FE0: 53 2C 20 42 45 4C 4F 57 2E 20 20 CE 4F 20 53 49 |S, BELOW. .O SI|
00012FF0: 4E 47 4C 45 20 49 4D 50 4C 45 4D 45 4E 54 41 54 |NGLE IMPLEMENTAT|
00013000: 49 4F 4E 20 4E 45 43 45 53 53 41 52 49 4C 59 20 |ION NECESSARILY |
00013010: 49 4E 43 4C 55 44 45 53 20 41 4C 4C 0D 54 48 45 |INCLUDES ALL.THE|
00013020: 20 46 45 41 54 55 52 45 53 20 4D 45 4E 54 49 4F | FEATURES MENTIO|
00013030: 4E 45 44 20 49 4E 20 54 48 49 53 20 41 52 54 49 |NED IN THIS ARTI|
00013040: 43 4C 45 2C 20 42 55 54 20 41 4C 4C 20 41 52 45 |CLE, BUT ALL ARE|
00013050: 20 41 42 4C 45 20 54 4F 20 43 4F 4D 4D 55 4E 49 | ABLE TO COMMUNI|
00013060: 43 41 54 45 20 41 54 0D 4C 45 41 53 54 20 41 54 |CATE AT.LEAST AT|
00013070: 20 42 41 53 45 20 4C 45 56 45 4C 2E 20 20 C1 44 | BASE LEVEL. .D|
00013080: 44 49 54 49 4F 4E 41 4C 20 49 4D 50 4C 45 4D 45 |DITIONAL IMPLEME|
00013090: 4E 54 41 54 49 4F 4E 53 20 41 52 45 20 49 4E 20 |NTATIONS ARE IN |
000130A0: 50 52 45 50 41 52 41 54 49 4F 4E 2C 20 41 4E 44 |PREPARATION, AND|
000130B0: 0D 50 52 45 53 45 4E 54 20 4F 4E 45 53 20 41 52 |.PRESENT ONES AR|
000130C0: 45 20 42 45 49 4E 47 20 45 4E 48 41 4E 43 45 44 |E BEING ENHANCED|
000130D0: 2E 0D 0D C3 4F 4C 55 4D 42 49 41 20 D5 4E 49 56 |....OLUMBIA .NIV|
000130E0: 45 52 53 49 54 59 20 49 53 20 57 49 4C 4C 49 4E |ERSITY IS WILLIN|
000130F0: 47 20 54 4F 20 50 52 4F 56 49 44 45 20 41 4C 4C |G TO PROVIDE ALL|
00013100: 20 CB C5 D2 CD C9 D4 20 50 52 4F 47 52 41 4D 53 | ...... PROGRAMS|
00013110: 2C 20 53 4F 55 52 43 45 53 2C 0D 4D 41 4E 55 41 |, SOURCES,.MANUA|
00013120: 4C 53 2C 20 41 4E 44 20 4F 54 48 45 52 20 44 4F |LS, AND OTHER DO|
00013130: 43 55 4D 45 4E 54 41 54 49 4F 4E 20 54 4F 20 43 |CUMENTATION TO C|
00013140: 4F 4D 50 55 54 49 4E 47 20 43 45 4E 54 45 52 53 |OMPUTING CENTERS|
00013150: 2C 20 41 43 41 44 45 4D 49 43 20 4F 52 20 43 4F |, ACADEMIC OR CO|
00013160: 52 50 4F 52 41 54 45 2C 0D 49 4E 20 52 45 54 55 |RPORATE,.IN RETU|
00013170: 52 4E 20 46 4F 52 20 41 20 4D 4F 44 45 53 54 20 |RN FOR A MODEST |
00013180: 46 45 45 20 54 4F 20 43 4F 56 45 52 20 43 4F 53 |FEE TO COVER COS|
00013190: 54 53 20 46 4F 52 20 4D 45 44 49 41 2C 20 50 52 |TS FOR MEDIA, PR|
000131A0: 49 4E 54 49 4E 47 2C 20 50 4F 53 54 41 47 45 2C |INTING, POSTAGE,|
000131B0: 20 4C 41 42 4F 52 2C 0D 41 4E 44 20 43 4F 4D 50 | LABOR,.AND COMP|
000131C0: 55 54 49 4E 47 20 52 45 53 4F 55 52 43 45 53 2E |UTING RESOURCES.|
000131D0: 20 20 CF 4E 4C 59 20 4D 41 47 4E 45 54 49 43 20 | .NLY MAGNETIC |
000131E0: 54 41 50 45 20 41 4E 44 20 4C 49 53 54 49 4E 47 |TAPE AND LISTING|
000131F0: 53 20 43 41 4E 20 42 45 20 53 48 49 50 50 45 44 |S CAN BE SHIPPED|
00013200: 2E 20 20 D7 45 0D 43 41 4E 4E 4F 54 20 50 52 4F |. .E.CANNOT PRO|
00013210: 44 55 43 45 20 46 4C 4F 50 50 59 20 44 49 53 4B |DUCE FLOPPY DISK|
00013220: 53 3B 20 49 4E 53 54 52 55 43 54 49 4F 4E 53 20 |S; INSTRUCTIONS |
00013230: 41 52 45 20 49 4E 43 4C 55 44 45 44 20 46 4F 52 |ARE INCLUDED FOR|
00013240: 20 42 4F 4F 54 53 54 52 41 50 50 49 4E 47 20 54 | BOOTSTRAPPING T|
00013250: 48 45 0D 4D 49 43 52 4F 43 4F 4D 50 55 54 45 52 |HE.MICROCOMPUTER|
00013260: 20 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E 53 | IMPLEMENTATIONS|
00013270: 20 46 52 4F 4D 20 54 48 45 20 4D 41 49 4E 46 52 | FROM THE MAINFR|
00013280: 41 4D 45 20 43 4F 4D 50 55 54 45 52 53 2E 20 20 |AME COMPUTERS. |
00013290: C4 45 54 41 49 4C 53 20 57 49 4C 4C 20 42 45 0D |.ETAILS WILL BE.|
000132A0: 50 52 4F 56 49 44 45 44 20 4F 4E 20 52 45 51 55 |PROVIDED ON REQU|
000132B0: 45 53 54 3B 20 57 52 49 54 45 20 54 4F 3A 0D 0D |EST; WRITE TO:..|
000132C0: CB C5 D2 CD C9 D4 20 C4 49 53 54 52 49 42 55 54 |...... .ISTRIBUT|
000132D0: 49 4F 4E 0D C3 4F 4C 55 4D 42 49 41 20 D5 4E 49 |ION..OLUMBIA .NI|
000132E0: 56 45 52 53 49 54 59 20 C3 45 4E 54 45 52 20 46 |VERSITY .ENTER F|
000132F0: 4F 52 20 C3 4F 4D 50 55 54 49 4E 47 20 C1 43 54 |OR .OMPUTING .CT|
00013300: 49 56 49 54 49 45 53 0D 37 54 48 20 C6 4C 4F 4F |IVITIES.7TH .LOO|
00013310: 52 2C 20 D7 41 54 53 4F 4E 20 CC 41 42 4F 52 41 |R, .ATSON .ABORA|
00013320: 54 4F 52 59 0D 36 31 32 20 D7 45 53 54 20 31 31 |TORY.612 .EST 11|
00013330: 35 54 48 20 D3 54 52 45 45 54 0D CE 45 57 20 D9 |5TH .TREET..EW .|
00013340: 4F 52 4B 2C 20 CE D9 20 20 31 30 30 32 35 0D 0D |ORK, .. 10025..|
00013350: D4 48 45 20 50 52 4F 54 4F 43 4F 4C 20 53 50 45 |.HE PROTOCOL SPE|
00013360: 43 49 46 49 43 41 54 49 4F 4E 20 53 55 50 50 4C |CIFICATION SUPPL|
00013370: 45 4D 45 4E 54 45 44 20 42 59 20 45 58 41 4D 50 |EMENTED BY EXAMP|
00013380: 4C 45 53 20 4F 46 20 45 58 49 53 54 49 4E 47 20 |LES OF EXISTING |
00013390: CB C5 D2 CD C9 D4 0D 49 4D 50 4C 45 4D 45 4E 54 |.......IMPLEMENT|
000133A0: 41 54 49 4F 4E 53 20 41 4C 4C 4F 57 53 20 4E 45 |ATIONS ALLOWS NE|
000133B0: 57 20 49 4D 50 4C 45 4D 45 4E 54 41 54 49 4F 4E |W IMPLEMENTATION|
000133C0: 53 20 54 4F 20 42 45 20 43 52 45 41 54 45 44 20 |S TO BE CREATED |
000133D0: 57 49 54 48 20 52 45 4C 41 54 49 56 45 20 45 41 |WITH RELATIVE EA|
000133E0: 53 45 2E 0D C9 4E 20 54 48 45 20 50 41 53 54 2C |SE...N THE PAST,|
000133F0: 20 CB C5 D2 CD C9 D4 20 49 4D 50 4C 45 4D 45 4E | ...... IMPLEMEN|
00013400: 54 4F 52 53 20 48 41 56 45 20 53 48 41 52 45 44 |TORS HAVE SHARED|
00013410: 20 54 48 45 49 52 20 57 4F 52 4B 20 57 49 54 48 | THEIR WORK WITH|
00013420: 20 4F 54 48 45 52 20 CB C5 D2 CD C9 D4 20 55 53 | OTHER ...... US|
00013430: 45 52 53 0D 42 59 20 43 4F 4E 54 52 49 42 55 54 |ERS.BY CONTRIBUT|
00013440: 49 4E 47 20 49 54 20 54 4F 20 54 48 45 20 C3 4F |ING IT TO THE .O|
00013450: 4C 55 4D 42 49 41 20 CB C5 D2 CD C9 D4 20 4C 49 |LUMBIA ...... LI|
00013460: 42 52 41 52 59 2E 20 20 D7 45 20 48 4F 50 45 20 |BRARY. .E HOPE |
00013470: 54 48 41 54 20 54 48 49 53 20 50 52 41 43 54 49 |THAT THIS PRACTI|
00013480: 43 45 0D 57 49 4C 4C 20 43 4F 4E 54 49 4E 55 45 |CE.WILL CONTINUE|
00013490: 20 55 4E 54 49 4C 20 CB C5 D2 CD C9 D4 20 48 41 | UNTIL ...... HA|
000134A0: 53 20 53 50 52 45 41 44 20 54 48 52 4F 55 47 48 |S SPREAD THROUGH|
000134B0: 4F 55 54 20 54 48 45 20 4B 4E 4F 57 4E 20 57 4F |OUT THE KNOWN WO|
000134C0: 52 4C 44 2E 0D 0D 0D C1 43 4B 4E 4F 57 4C 45 44 |RLD.....CKNOWLED|
000134D0: 47 45 4D 45 4E 54 53 0D 3D 3D 3D 3D 3D 3D 3D 3D |GEMENTS.========|
000134E0: 3D 3D 3D 3D 3D 3D 3D 3D 0D 0D C9 4E 20 44 45 53 |========...N DES|
000134F0: 49 47 4E 49 4E 47 20 54 48 45 20 49 4E 49 54 49 |IGNING THE INITI|
00013500: 41 4C 20 CB C5 D2 CD C9 D4 20 50 52 4F 54 4F 43 |AL ...... PROTOC|
00013510: 4F 4C 2C 20 57 45 20 53 54 55 44 49 45 44 20 53 |OL, WE STUDIED S|
00013520: 45 56 45 52 41 4C 20 4D 4F 44 45 4C 53 2C 20 50 |EVERAL MODELS, P|
00013530: 52 49 4D 41 52 49 4C 59 0D 54 48 45 20 C1 CE D3 |RIMARILY.THE ...|
00013540: C9 20 52 45 43 4F 4D 4D 45 4E 44 41 54 49 4F 4E |. RECOMMENDATION|
00013550: 2E 20 CF 54 48 45 52 53 20 49 4E 43 4C 55 44 45 |. .THERS INCLUDE|
00013560: 20 54 48 45 20 D3 54 41 4E 46 4F 52 44 20 D5 4E | THE .TANFORD .N|
00013570: 49 56 45 52 53 49 54 59 20 C4 C9 C1 CC CE C5 D4 |IVERSITY .......|
00013580: 0D 50 52 4F 4A 45 43 54 2C 20 54 48 45 20 D5 4E |.PROJECT, THE .N|
00013590: 49 56 45 52 53 49 54 59 20 4F 46 20 D5 54 41 48 |IVERSITY OF .TAH|
000135A0: 20 22 D3 4D 41 4C 4C 20 C6 D4 D0 22 20 50 52 4F | ".MALL ..." PRO|
000135B0: 4A 45 43 54 2C 20 41 4E 44 20 54 48 45 20 D3 54 |JECT, AND THE .T|
000135C0: 41 4E 46 4F 52 44 0D D5 4E 49 56 45 52 53 49 54 |ANFORD..NIVERSIT|
000135D0: 59 20 CD 45 44 49 43 41 4C 20 C3 45 4E 54 45 52 |Y .EDICAL .ENTER|
000135E0: 20 D4 D4 D9 C6 D4 D0 20 50 52 4F 4A 45 43 54 2E | ...... PROJECT.|
000135F0: 20 C1 4E 44 20 57 45 20 45 58 41 4D 49 4E 45 44 | .ND WE EXAMINED|
00013600: 20 53 4F 4D 45 20 52 45 41 4C 20 4E 45 54 57 4F | SOME REAL NETWO|
00013610: 52 4B 53 2C 0D 4C 49 4B 45 20 C1 D2 D0 C1 CE C5 |RKS,.LIKE ......|
00013620: D4 20 41 4E 44 20 C4 C5 C3 4E 45 54 2E 0D 0D C1 |. AND ...NET....|
00013630: 43 4B 4E 4F 57 4C 45 44 47 45 4D 45 4E 54 53 20 |CKNOWLEDGEMENTS |
00013640: 41 4C 53 4F 20 54 4F 20 54 48 45 20 4D 41 4E 59 |ALSO TO THE MANY|
00013650: 20 53 49 54 45 53 20 54 48 41 54 20 48 41 56 45 | SITES THAT HAVE|
00013660: 20 43 4F 4E 54 52 49 42 55 54 45 44 20 4E 45 57 | CONTRIBUTED NEW|
00013670: 20 CB C5 D2 CD C9 D4 0D 49 4D 50 4C 45 4D 45 4E | .......IMPLEMEN|
00013680: 54 41 54 49 4F 4E 53 20 4F 52 20 45 4E 48 41 4E |TATIONS OR ENHAN|
00013690: 43 45 44 20 4F 4C 44 20 4F 4E 45 53 3A 20 D3 54 |CED OLD ONES: .T|
000136A0: 45 56 45 4E 53 20 C9 4E 53 54 49 54 55 54 45 20 |EVENS .NSTITUTE |
000136B0: 4F 46 20 D4 45 43 48 4E 4F 4C 4F 47 59 2C 20 C4 |OF .ECHNOLOGY, .|
000136C0: 49 47 49 54 41 4C 0D C5 51 55 49 50 4D 45 4E 54 |IGITAL..QUIPMENT|
000136D0: 20 C3 4F 52 50 4F 52 41 54 49 4F 4E 2C 20 54 48 | .ORPORATION, TH|
000136E0: 45 20 CE 41 54 49 4F 4E 41 4C 20 C9 4E 53 54 49 |E .ATIONAL .NSTI|
000136F0: 54 55 54 45 53 20 4F 46 20 C8 45 41 4C 54 48 2C |TUTES OF .EALTH,|
00013700: 20 C3 4F 52 4E 45 4C 4C 20 D5 4E 49 56 45 52 53 | .ORNELL .NIVERS|
00013710: 49 54 59 2C 0D 54 48 45 20 D5 4E 49 56 45 52 53 |ITY,.THE .NIVERS|
00013720: 49 54 59 20 4F 46 20 D4 4F 52 4F 4E 54 4F 2C 20 |ITY OF .ORONTO, |
00013730: 54 48 45 20 D5 4E 49 56 45 52 53 49 54 59 20 4F |THE .NIVERSITY O|
00013740: 46 20 D4 45 4E 4E 45 53 53 45 45 2C 20 54 48 45 |F .ENNESSEE, THE|
00013750: 20 D5 4E 49 56 45 52 53 49 54 59 20 4F 46 0D D4 | .NIVERSITY OF..|
00013760: 4F 4C 45 44 4F 2C 20 C3 45 52 52 49 54 4F 53 20 |OLEDO, .ERRITOS |
00013770: C3 4F 4C 4C 45 47 45 2C 20 41 4E 44 20 4D 41 4E |.OLLEGE, AND MAN|
00013780: 59 20 4F 54 48 45 52 53 2E 20 20 D4 48 41 4E 4B |Y OTHERS. .HANK|
00013790: 53 20 54 4F 20 C4 52 2E 20 C8 4F 57 41 52 44 20 |S TO .R. .OWARD |
000137A0: C5 53 4B 49 4E 20 46 4F 52 0D 48 45 4C 50 20 57 |.SKIN FOR.HELP W|
000137B0: 49 54 48 20 54 48 49 53 20 41 52 54 49 43 4C 45 |ITH THIS ARTICLE|
000137C0: 2E 0D 0D 0D D4 48 45 20 C1 D3 C3 C9 C9 20 C1 4C |.....HE ..... .L|
000137D0: 50 48 41 42 45 54 0D 3D 3D 3D 3D 3D 3D 3D 3D 3D |PHABET.=========|
000137E0: 3D 3D 3D 3D 3D 3D 3D 3D 3D 0D 0D C4 45 43 20 CF |=========...EC .|
000137F0: 43 54 20 C3 48 41 52 41 43 54 45 52 20 20 C4 45 |CT .HARACTER .E|
00013800: 43 20 CF 43 54 0D 0D 30 30 30 20 30 30 30 20 CE |C .CT..000 000 .|
00013810: D5 CC 20 28 5E 40 29 20 20 20 30 36 34 20 31 30 |.. (^@) 064 10|
00013820: 30 20 40 0D 30 30 31 20 30 30 31 20 D3 CF C8 20 |0 @.001 001 ... |
00013830: 28 5E C1 29 20 20 20 30 36 35 20 31 30 31 20 C1 |(^.) 065 101 .|
00013840: 0D 30 30 32 20 30 30 32 20 D3 D4 D8 20 28 5E C2 |.002 002 ... (^.|
00013850: 29 20 20 20 30 36 36 20 31 30 32 20 C2 0D 30 30 |) 066 102 ..00|
00013860: 33 20 30 30 33 20 C5 D4 D8 20 28 5E C3 29 20 20 |3 003 ... (^.) |
00013870: 20 30 36 37 20 31 30 33 20 C3 0D 30 30 34 20 30 | 067 103 ..004 0|
00013880: 30 34 20 C5 CF D4 20 28 5E C4 29 20 20 20 30 36 |04 ... (^.) 06|
00013890: 38 20 31 30 34 20 C4 0D 30 30 35 20 30 30 35 20 |8 104 ..005 005 |
000138A0: C5 CE D1 20 28 5E C5 29 20 20 20 30 36 39 20 31 |... (^.) 069 1|
000138B0: 30 35 20 C5 0D 30 30 36 20 30 30 36 20 C1 C3 CB |05 ..006 006 ...|
000138C0: 20 28 5E C6 29 20 20 20 30 37 30 20 31 30 36 20 | (^.) 070 106 |
000138D0: C6 0D 30 30 37 20 30 30 37 20 C2 C5 CC 20 28 5E |..007 007 ... (^|
000138E0: C7 29 20 20 20 30 37 31 20 31 30 37 20 C7 0D 30 |.) 071 107 ..0|
000138F0: 30 38 20 30 31 30 20 C2 D3 20 20 28 5E C8 29 20 |08 010 .. (^.) |
00013900: 20 20 30 37 32 20 31 31 30 20 C8 0D 30 30 39 20 | 072 110 ..009 |
00013910: 30 31 31 20 C8 D4 20 20 28 5E C9 29 20 20 20 30 |011 .. (^.) 0|
00013920: 37 33 20 31 31 31 20 C9 0D 30 31 30 20 30 31 32 |73 111 ..010 012|
00013930: 20 CC C6 20 20 28 5E CA 29 20 20 20 30 37 34 20 | .. (^.) 074 |
00013940: 31 31 32 20 CA 0D 30 31 31 20 30 31 33 20 D6 D4 |112 ..011 013 ..|
00013950: 20 20 28 5E CB 29 20 20 20 30 37 35 20 31 31 33 | (^.) 075 113|
00013960: 20 CB 0D 30 31 32 20 30 31 34 20 C6 C6 20 20 28 | ..012 014 .. (|
00013970: 5E CC 29 20 20 20 30 37 36 20 31 31 34 20 CC 0D |^.) 076 114 ..|
00013980: 30 31 33 20 30 31 35 20 C3 D2 20 20 28 5E CD 29 |013 015 .. (^.)|
00013990: 20 20 20 30 37 37 20 31 31 35 20 CD 0D 30 31 34 | 077 115 ..014|
000139A0: 20 30 31 36 20 D3 CF 20 20 28 5E CE 29 20 20 20 | 016 .. (^.) |
000139B0: 30 37 38 20 31 31 36 20 CE 0D 30 31 35 20 30 31 |078 116 ..015 01|
000139C0: 37 20 D3 C9 20 20 28 5E CF 29 20 20 20 30 37 39 |7 .. (^.) 079|
000139D0: 20 31 31 37 20 CF 0D 30 31 36 20 30 32 30 20 C4 | 117 ..016 020 .|
000139E0: CC C5 20 28 5E D0 29 20 20 20 30 38 30 20 31 32 |.. (^.) 080 12|
000139F0: 30 20 D0 0D 30 31 37 20 30 32 31 20 C4 C3 31 20 |0 ..017 021 ..1 |
00013A00: 28 5E D1 29 20 20 20 30 38 31 20 31 32 31 20 D1 |(^.) 081 121 .|
00013A10: 0D 30 31 38 20 30 32 32 20 C4 C3 32 20 28 5E D2 |.018 022 ..2 (^.|
00013A20: 29 20 20 20 30 38 32 20 31 32 32 20 D2 0D 30 31 |) 082 122 ..01|
00013A30: 39 20 30 32 33 20 C4 C3 33 20 28 5E D3 29 20 20 |9 023 ..3 (^.) |
00013A40: 20 30 38 33 20 31 32 33 20 D3 0D 30 32 30 20 30 | 083 123 ..020 0|
00013A50: 32 34 20 C4 C3 34 20 28 5E D4 29 20 20 20 30 38 |24 ..4 (^.) 08|
00013A60: 34 20 31 32 34 20 D4 0D 30 32 31 20 30 32 35 20 |4 124 ..021 025 |
00013A70: CE C1 CB 20 28 5E D5 29 20 20 20 30 38 35 20 31 |... (^.) 085 1|
00013A80: 32 35 20 D5 0D 30 32 32 20 30 32 36 20 D3 D9 CE |25 ..022 026 ...|
00013A90: 20 28 5E D6 29 20 20 20 30 38 36 20 31 32 36 20 | (^.) 086 126 |
00013AA0: D6 0D 30 32 33 20 30 32 37 20 C5 D4 C2 20 28 5E |..023 027 ... (^|
00013AB0: D7 29 20 20 20 30 38 37 20 31 32 37 20 D7 0D 30 |.) 087 127 ..0|
00013AC0: 32 34 20 30 33 30 20 C3 C1 CE 20 28 5E D8 29 20 |24 030 ... (^.) |
00013AD0: 20 20 30 38 38 20 31 33 30 20 D8 0D 30 32 35 20 | 088 130 ..025 |
00013AE0: 30 33 31 20 C5 CD 20 20 28 5E D9 29 20 20 20 30 |031 .. (^.) 0|
00013AF0: 38 39 20 31 33 31 20 D9 0D 30 32 36 20 30 33 32 |89 131 ..026 032|
00013B00: 20 D3 D5 C2 20 28 5E DA 29 20 20 20 30 39 30 20 | ... (^.) 090 |
00013B10: 31 33 32 20 DA 0D 30 32 37 20 30 33 33 20 C5 D3 |132 ..027 033 ..|
00013B20: C3 20 28 5E 5B 29 20 20 20 30 39 31 20 31 33 33 |. (^[) 091 133|
00013B30: 20 5B 0D 30 32 38 20 30 33 34 20 C6 D3 20 20 28 | [.028 034 .. (|
00013B40: 5E 5C 29 20 20 20 30 39 32 20 31 33 34 20 5C 0D |^\) 092 134 \.|
00013B50: 30 32 39 20 30 33 35 20 C7 D3 20 20 28 5E 5D 29 |029 035 .. (^])|
00013B60: 20 20 20 30 39 33 20 31 33 35 20 5D 0D 30 33 30 | 093 135 ].030|
00013B70: 20 30 33 36 20 D2 D3 20 20 28 5E 5E 29 20 20 20 | 036 .. (^^) |
00013B80: 30 39 34 20 31 33 36 20 5E 0D 30 33 31 20 30 33 |094 136 ^.031 03|
00013B90: 37 20 D5 D3 20 20 28 5E 5F 29 20 20 20 30 39 35 |7 .. (^_) 095|
00013BA0: 20 31 33 37 20 5F 0D 30 33 32 20 30 34 30 20 20 | 137 _.032 040 |
00013BB0: 20 20 20 28 D3 D0 29 20 20 20 30 39 36 20 31 34 | (..) 096 14|
00013BC0: 30 20 20 0D 30 33 33 20 30 34 31 20 21 20 20 20 |0 .033 041 ! |
00013BD0: 20 20 20 20 20 20 20 30 39 37 20 31 34 31 20 41 | 097 141 A|
00013BE0: 0D 30 33 34 20 30 34 32 20 22 20 20 20 20 20 20 |.034 042 " |
00013BF0: 20 20 20 20 30 39 38 20 31 34 32 20 42 0D 30 33 | 098 142 B.03|
00013C00: 35 20 30 34 33 20 23 20 20 20 20 20 20 20 20 20 |5 043 # |
00013C10: 20 30 39 39 20 31 34 33 20 43 0D 30 33 36 20 30 | 099 143 C.036 0|
00013C20: 34 34 20 24 20 20 20 20 20 20 20 20 20 20 31 30 |44 $ 10|
00013C30: 30 20 31 34 34 20 44 0D 30 33 37 20 30 34 35 20 |0 144 D.037 045 |
00013C40: 25 20 20 20 20 20 20 20 20 20 20 31 30 31 20 31 |% 101 1|
00013C50: 34 35 20 45 0D 30 33 38 20 30 34 36 20 26 20 20 |45 E.038 046 & |
00013C60: 20 20 20 20 20 20 20 20 31 30 32 20 31 34 36 20 | 102 146 |
00013C70: 46 0D 30 33 39 20 30 34 37 20 27 20 20 20 20 20 |F.039 047 ' |
00013C80: 20 20 20 20 20 31 30 33 20 31 34 37 20 47 0D 30 | 103 147 G.0|
00013C90: 34 30 20 30 35 30 20 28 20 20 20 20 20 20 20 20 |40 050 ( |
00013CA0: 20 20 31 30 34 20 31 35 30 20 48 0D 30 34 31 20 | 104 150 H.041 |
00013CB0: 30 35 31 20 29 20 20 20 20 20 20 20 20 20 20 31 |051 ) 1|
00013CC0: 30 35 20 31 35 31 20 49 0D 30 34 32 20 30 35 32 |05 151 I.042 052|
00013CD0: 20 2A 20 20 20 20 20 20 20 20 20 20 31 30 36 20 | * 106 |
00013CE0: 31 35 32 20 4A 0D 30 34 33 20 30 35 33 20 2B 20 |152 J.043 053 + |
00013CF0: 20 20 20 20 20 20 20 20 20 31 30 37 20 31 35 33 | 107 153|
00013D00: 20 4B 0D 30 34 34 20 30 35 34 20 2C 20 20 20 20 | K.044 054 , |
00013D10: 20 20 20 20 20 20 31 30 38 20 31 35 34 20 4C 0D | 108 154 L.|
00013D20: 30 34 35 20 30 35 35 20 2D 20 20 20 20 20 20 20 |045 055 - |
00013D30: 20 20 20 31 30 39 20 31 35 35 20 4D 0D 30 34 36 | 109 155 M.046|
00013D40: 20 30 35 36 20 2E 20 20 20 20 20 20 20 20 20 20 | 056 . |
00013D50: 31 31 30 20 31 35 36 20 4E 0D 30 34 37 20 30 35 |110 156 N.047 05|
00013D60: 37 20 2F 20 20 20 20 20 20 20 20 20 20 31 31 31 |7 / 111|
00013D70: 20 31 35 37 20 4F 0D 30 34 38 20 30 36 30 20 30 | 157 O.048 060 0|
00013D80: 20 20 20 20 20 20 20 20 20 20 31 31 32 20 31 36 | 112 16|
00013D90: 30 20 50 0D 30 34 39 20 30 36 31 20 31 20 20 20 |0 P.049 061 1 |
00013DA0: 20 20 20 20 20 20 20 31 31 33 20 31 36 31 20 51 | 113 161 Q|
00013DB0: 0D 30 35 30 20 30 36 32 20 32 20 20 20 20 20 20 |.050 062 2 |
00013DC0: 20 20 20 20 31 31 34 20 31 36 32 20 52 0D 30 35 | 114 162 R.05|
00013DD0: 31 20 30 36 33 20 33 20 20 20 20 20 20 20 20 20 |1 063 3 |
00013DE0: 20 31 31 35 20 31 36 33 20 53 0D 30 35 32 20 30 | 115 163 S.052 0|
00013DF0: 36 34 20 34 20 20 20 20 20 20 20 20 20 20 31 31 |64 4 11|
00013E00: 36 20 31 36 34 20 54 0D 30 35 33 20 30 36 35 20 |6 164 T.053 065 |
00013E10: 35 20 20 20 20 20 20 20 20 20 20 31 31 37 20 31 |5 117 1|
00013E20: 36 35 20 55 0D 30 35 34 20 30 36 36 20 36 20 20 |65 U.054 066 6 |
00013E30: 20 20 20 20 20 20 20 20 31 31 38 20 31 36 36 20 | 118 166 |
00013E40: 56 0D 30 35 35 20 30 36 37 20 37 20 20 20 20 20 |V.055 067 7 |
00013E50: 20 20 20 20 20 31 31 39 20 31 36 37 20 57 0D 30 | 119 167 W.0|
00013E60: 35 36 20 30 37 30 20 38 20 20 20 20 20 20 20 20 |56 070 8 |
00013E70: 20 20 31 32 30 20 31 37 30 20 58 0D 30 35 37 20 | 120 170 X.057 |
00013E80: 30 37 31 20 39 20 20 20 20 20 20 20 20 20 20 31 |071 9 1|
00013E90: 32 31 20 31 37 31 20 59 0D 30 35 38 20 30 37 32 |21 171 Y.058 072|
00013EA0: 20 3A 20 20 20 20 20 20 20 20 20 20 31 32 32 20 | : 122 |
00013EB0: 31 37 32 20 5A 0D 30 35 39 20 30 37 33 20 3B 20 |172 Z.059 073 ; |
00013EC0: 20 20 20 20 20 20 20 20 20 31 32 33 20 31 37 33 | 123 173|
00013ED0: 20 3B 0D 30 36 30 20 30 37 34 20 3C 20 20 20 20 | ;.060 074 < |
00013EE0: 20 20 20 20 20 20 31 32 34 20 31 37 34 20 5D 0D | 124 174 ].|
00013EF0: 30 36 31 20 30 37 35 20 3D 20 20 20 20 20 20 20 |061 075 = |
00013F00: 20 20 20 31 32 35 20 31 37 35 20 3D 0D 30 36 32 | 125 175 =.062|
00013F10: 20 30 37 36 20 3E 20 20 20 20 20 20 20 20 20 20 | 076 > |
00013F20: 31 32 36 20 31 37 36 20 3E 0D 30 36 33 20 30 37 |126 176 >.063 07|
00013F30: 37 20 3F 20 20 20 20 20 20 20 20 20 20 31 32 37 |7 ? 127|
00013F40: 20 31 37 37 20 C4 C5 CC 0D 0D 0D 2A 20 2A 20 2A | 177 ......* * *|
00013F50: 20 C5 CE C4 20 CF C6 20 C6 C9 CC C5 20 2A 20 2A | ... .. .... * *|
00013F60: 20 2A 0D 0D C7 52 45 45 54 49 4E 47 53 20 54 4F | *...REETINGS TO|
00013F70: 20 41 4C 4C 20 CB 45 52 4D 49 54 2D D5 53 45 52 | ALL .ERMIT-.SER|
00013F80: 53 20 2E 2E 2E 2E 2E 2E C8 C1 C9 0D 0D D2 3B 20 |S ............; |
00013F90: D4 3D 30 2E 37 33 2F 32 2E 35 39 20 31 34 3A 34 |.=0.73/2.59 14:4|
00013FA0: 37 3A 30 31 0D |7:01. |
.FILE:BYTE.DOC / FROM:KERMSRV AT CUVMA.B
ITNET / TRANSFER BY HAI...KERMIT.======.
.THIS IS THE ORIGINAL MANUSCRIPT OF THE
ARTICLE PUBLISHED IN BYTE MAGAZINE AS."K
ERMIT: A FILE TRANSFER PROTOCOL FOR UNIV
ERSITIES", JUNE AND JULY 1984..SOME MINO
R EDITORIAL DIFFERENCES EXIST BETWEEN TH
IS MANUSCRIPT AND THE ARTICLE.AS PUBLISH
ED. THE KERMIT FILE TRANSFER PROTOCOL IS
NAMED AFTER KERMIT THE FROG,.STAR OF TH
E TELEVISION SERIES THE MUPPET SHOW, USE
D BY PERMISSION OF HENSON.ASSOCIATES, IN
C....A SIMPLE FILE TRANSFER PROTOCOL FOR
MICROCOMPUTERS AND MAINFRAMES...FRANK D
A CRUZ, BILL CATCHINGS.COLUMBIA UNIVERSI
TY CENTER FOR COMPUTING ACTIVITIES.NEW Y
ORK, N.Y. 10027.MAY 1983...DURING RECEN
T YEARS, THE TECHNICAL PRESS HAS FOCUSED
A LOT OF ATTENTION ON.DEVELOPMENTS IN C
OMPUTER NETWORKING - THE IEEE 802 COMMIT
TEE, TCP/IP, SNA,.THE LATEST VLSI ETHERN
ET INTERFACE, FIBRE OPTICS, SATELLITE CO
MMUNICATIONS,.BROADBAND VERSUS BASEBAND.
BUT LITTLE ATTENTION HAS BEEN GIVEN TO
THE SINGLE.MECHANISM THAT MAY BE THE MO
ST WIDELY USED IN THE REAL WORLD FOR DIR
ECT INTER-.PROCESSOR COMMUNICATION: THE
SO-CALLED "ASYNCHRONOUS PROTOCOL", WHICH
IS TO BE.FOUND IN SOME FORM AT ALMOST E
VERY INSTITUTION WHERE THERE IS A NEED T
O.TRANSFER FILES BETWEEN MICROCOMPUTERS
AND CENTRAL COMPUTERS...COLUMBIA UNIVERS
ITY IS SUCH AN INSTITUTION. LARGE TIMES
HARING COMPUTERS AT A.CENTRAL SITE ARE C
OMPLEMENTED BY MANY SMALLER SYSTEMS SCAT
TERED IN THE.LABORATORIES AND DEPARTMENT
S. THE PAST FEW YEARS HAVE WITNESSED TH
E INEXORABLE.PROGRESS OF DIVERSE MICROCO
MPUTERS, WORD PROCESSORS, AND PROFESSION
AL WORK-.STATIONS INTO OFFICES AND LABOR
ATORIES THROUGHOUT THE UNIVERSITY, AND I
NTO THE.HOMES OR DORMITORY ROOMS OF FACU
LTY, STUDENTS, AND STAFF. AS SOON AS TH
ESE.SMALL MACHINES BEGAN TO APPEAR, THEI
R USERS ASKED FOR WAYS TO EXCHANGE FILES
.WITH THE CENTRAL AND DEPARTMENTAL SYSTE
MS...AT THE SAME TIME, STUDENT USE OF OU
R CENTRAL SYSTEMS WAS GROWING AT AN.ASTO
NISHING RATE. WE COULD NO LONGER AFFORD
TO PROVIDE STUDENTS WITH PERPETUAL.ONLIN
E DISK STORAGE; WE BEGAN TO ISSUE IDS PE
R COURSE, PER TERM. WITH THE.DECREASED
LONGEVITY OF THE IDS CAME THE NEED FOR S
TUDENTS TO ECONOMICALLY.ARCHIVE THEIR FI
LES. GIVEN A RELIABLE WAY TO FROM THE C
ENTRAL MAINFRAMES AND.BACK, MICROCOMPUTE
RS WITH FLOPPY DISKS COULD PROVIDE INEXP
ENSIVE REMOVABLE.MEDIA IDEAL FOR THIS PU
RPOSE...THE SITUATION CALLED FOR A FILE
TRANSFER MECHANISM THAT COULD WORK AMONG
ALL.OUR COMPUTERS, LARGE AND SMALL. WE
KNEW OF NONE THAT COULD HANDLE THE REQU
IRED.DIVERSITY. SOME WERE INTENDED FOR
USE BETWEEN MICROCOMPUTERS, OTHERS BETWE
EN.LARGE COMPUTERS, BUT NONE SPECIFICALL
Y ADDRESSED THE NEED FOR COMMUNICATION.A
MONG THE WIDEST POSSIBLE RANGE OF COMPUT
ERS, PARTICULARLY BETWEEN MICROS AND.OUR
IBM AND DEC MAINFRAMES. MOST COMMERCIA
L PACKAGES SERVED A LIMITED SET OF.SYSTE
MS, AND THEIR COST WOULD HAVE BEEN PROHI
BITIVE WHEN MULTIPLIED BY THE.LARGE NUMB
ER OF MACHINES WE NEEDED TO SUPPORT...SO
WE EMBARKED ON OUR OWN PROJECT. WE WER
E NOT WELL-VERSED IN THESE MATTERS.AT TH
E OUTSET; WE LEARNED AS WE PROCEEDED, AN
D WE'RE STILL LEARNING. THIS.ARTICLE DI
SCUSSES SOME OF THE ISSUES AND TRADEOFFS
THAT CAME UP IN THE DESIGN,.AND ILLUSTR
ATES THEM IN TERMS OF OUR RESULT, THE KE
RMIT PROTOCOL FOR.POINT-TO-POINT FILE TR
ANSFER OVER TELECOMMUNICATION LINES. BE
CAUSE COMMERCIAL.LOCAL AREA NETWORKING P
RODUCTS ARE EXPENSIVE, NOT YET WIDELY AV
AILABLE, AND.UNSUITABLE FOR ONE-SHOT OR
LONG-HAUL APPLICATIONS, HUMBLE ASYNCHRON
OUS.PROTOCOLS SUCH AS KERMIT ARE LIKELY
TO BE WITH US FOR A LONG TIME TO COME...
IT IS ASSUMED THE READER IS FAMILIAR WIT
H COMMON COMPUTING AND TELECOMMUNICA-.TI
ONS TERMINOLOGY, AND WITH THE ASCII ALPH
ABET, WHICH IS LISTED AT THE END OF.THIS
ARTICLE FOR REFERENCE....THE COMMUNICAT
ION MEDIUM..THE ONLY COMMUNICATION MEDIU
M COMMON TO ALL COMPUTERS, LARGE AND SMA
LL, IS THE.ASYNCHRONOUS SERIAL TELECOMMU
NICATION LINE, USED FOR CONNECTING TERMI
NALS TO.COMPUTERS. STANDARDS FOR THIS M
EDIUM ARE ALMOST UNIVERSALLY FOLLOWED -.
CONNECTORS, VOLTAGES, AND SIGNALS (EIA R
S-232-C), CHARACTER ENCODING (ASCII,.ANS
I X3.4-1977), AND BIT TRANSMISSION SEQUE
NCE (ANSI X3.15-1976). SERIAL.CONNECTIO
NS CAN BE MADE IN MANY WAYS: DEDICATED L
OCAL LINES ("NULL MODEM".CABLES), LEASED
TELEPHONE CIRCUITS, DIALUP CONNECTIONS.
DIALUP CONNECTIONS.CAN BE INITIATED MA
NUALLY FROM THE HOME OR OFFICE USING AN
INEXPENSIVE ACOUSTIC.COUPLER, OR AUTOMAT
ICALLY FROM ONE COMPUTER TO ANOTHER USIN
G A PROGRAMMABLE.DIALOUT MECHANISM. THE
ASYNCHRONOUS SERIAL LINE OFFERS THE ORD
INARY USER A.HIGH DEGREE OF CONVENIENCE
AND CONTROL IN ESTABLISHING INTERSYSTEM
CONNECTIONS,.AT RELATIVELY LOW COST...ON
CE TWO COMPUTERS ARE CONNECTED WITH A SE
RIAL LINE, INFORMATION CAN BE TRANS-.FER
RED FROM ONE MACHINE TO THE OTHER, PROVI
DED ONE SIDE CAN BE INSTRUCTED TO.SEND T
HE INFORMATION AND THE OTHER TO RECEIVE
IT. BUT RIGHT AWAY, SEVERAL.IMPORTANT F
ACTORS COME INTO PLAY:..NOISE -- IT IS R
ARELY SAFE TO ASSUME THAT THERE WILL BE
NO ELECTRICAL INTER-.FERENCE ON A LINE;
ANY LONG OR SWITCHED DATA COMMUNICATION
LINE WILL HAVE.OCCASIONAL INTERFERENCE,
OR NOISE, WHICH TYPICALLY RESULTS IN GAR
BLED OR EXTRA.CHARACTERS. NOISE CORRUPTS
DATA, PERHAPS IN SUBTLE WAYS THAT MIGHT
NOT BE.NOTICED UNTIL IT'S TOO LATE...SY
NCHRONIZATION -- DATA MUST NOT COME IN F
ASTER THAN THE RECEIVING MACHINE CAN.HAN
DLE IT. ALTHOUGH LINE SPEEDS AT THE TWO
ENDS OF THE CONNECTION MAY MATCH,.THE RE
CEIVING MACHINE MIGHT NOT BE ABLE TO PRO
CESS A STEADY STREAM OF INPUT AT.THAT SP
EED. ITS CENTRAL PROCESSOR MAY BE TOO SL
OW OR TOO HEAVILY LOADED, OR ITS.BUFFERS
TOO FULL OR TOO SMALL. THE TYPICAL SYMP
TOM OF A SYNCHRONIZATION PROBLEM.IS LOST
DATA; MOST OPERATING SYSTEMS WILL SIMPL
Y DISCARD INCOMING DATA THEY ARE.NOT PRE
PARED TO RECEIVE...LINE OUTAGES -- A LIN
E MAY STOP WORKING FOR SHORT PERIODS BEC
AUSE OF A FAULTY.CONNECTOR, LOSS OF POWE
R, OR SIMILAR REASON. ON DIALUP OR SWITC
HED CONNECTIONS,.SUCH INTERMITTENT FAILU
RES WILL CAUSE CARRIER TO DROP AND THE C
ONNECTION TO BE.CLOSED, BUT FOR ANY CONN
ECTION IN WHICH THE CARRIER SIGNAL IS NO
T USED, THE.SYMPTOM WILL BE LOST DATA...
OTHER COMMUNICATION MEDIA, SUCH AS THE P
ARALLEL DATA BUS, HAVE SAFEGUARDS BUILT.
IN TO PREVENT OR MINIMIZE THESE EFFECTS.
FOR INSTANCE, DISTANCES MAY BE.STRICTL
Y LIMITED, THE ENVIRONMENT CONTROLLED; S
PECIAL SIGNALS MAY BE AVAILABLE.FOR SYNC
HRONIZATION, AND SO FORTH. THE SERIAL T
ELECOMMUNICATION LINE PROVIDES.NO SUCH S
AFEGUARDS, AND WE MUST THEREFORE REGARD
IT AS AN INTRINSICALLY.UNRELIABLE MEDIUM
....GETTING RELIABLE COMMUNICATION OVER
AN UNRELIABLE MEDIUM..TO DETERMINE WHETH
ER DATA HAS BEEN TRANSMITTED BETWEEN TWO
MACHINES CORRECTLY.AND COMPLETELY, THE
TWO MACHINES CAN COMPARE THE DATA BEFORE
AND AFTER TRANS-.MISSION. A SCHEME THAT
IS COMMONLY USED FOR FILE TRANSFER EMPL
OYS COOPERATING.PROGRAMS RUNNING SIMULTA
NEOUSLY ON EACH MACHINE, COMMUNICATING I
N A WELL-.DEFINED, CONCISE LANGUAGE. TH
E SENDING PROGRAM DIVIDES OUTBOUND DATA
INTO.DISCRETE PIECES, ADDING TO EACH PIE
CE SPECIAL INFORMATION DESCRIBING THE DA
TA.FOR THE RECEIVING PROGRAM. THE RESULT
IS CALLED A "PACKET". THE RECEIVER.SEP
ARATES THE DESCRIPTION FROM THE DATA AND
DETERMINES WHETHER THEY STILL.MATCH. IF
SO, THE PACKET IS ACKNOWLEDGED AND THE
TRANSFER PROCEEDS. IF NOT,.THE PACKET IS
"NEGATIVELY ACKNOWLEDGED" AND THE SENDE
R RETRANSMITS IT; THIS.PROCEDURE REPEATS
FOR EACH PACKET UNTIL IT IS RECEIVED CO
RRECTLY...THE PROCESS IS CALLED A COMMUN
ICATION PROTOCOL - A SET OF RULES FOR FO
RMING.AND TRANSMITTING PACKETS, CARRIED
OUT BY PROGRAMS THAT EMBODY THOSE RULES.
.PROTOCOLS VARY IN COMPLEXITY; OUR PREFE
RENCE WAS FOR A SIMPLE APPROACH THAT.COU
LD BE REALIZED IN ALMOST ANY LANGUAGE ON
ALMOST ANY COMPUTER BY A PROGRAMMER.OF
MODERATE SKILL, ALLOWING THE PROTOCOL TO
BE ADAPTED EASILY TO NEW SYSTEMS.....AC
COMMODATING DIVERSE SYSTEMS.============
=================..MOST SYSTEMS AGREE HO
W TO COMMUNICATE AT THE LOWEST LEVELS -
THE EIA RS-232-C.ASYNCHRONOUS COMMUNICAT
ION LINE AND THE ASCII CHARACTER SET - B
UT THERE IS.RARELY AGREEMENT BEYOND THAT
. TO AVOID A DESIGN THAT MIGHT LOCK OUT
SOME KINDS.OF SYSTEMS, WE MUST CONSIDER
CERTAIN IMPORTANT WAYS IN WHICH SYSTEMS
CAN.DIFFER...MAINFRAMES VS MICROS..A DI
STINCTION MUST FIRST BE MADE BETWEEN MIC
ROS AND MAINFRAMES. THESE TERMS.ARE NOT
USED PERJORATIVELY; A "MICRO" COULD BE
A POWERFUL WORKSTATION, AND A."MAINFRAME
" COULD BE A SMALL MINICOMPUTER. FOR OU
R PURPOSES, A MICRO IS ANY.SINGLE-USER S
YSTEM IN WHICH THE SERIAL COMMUNICATION
PORT IS STRICTLY AN.EXTERNAL DEVICE. A
MAINFRAME IS ANY SYSTEM WHICH IS "HOST"
TO MULTIPLE.SIMULTANEOUS TERMINAL USERS,
WHO LOG IN TO "JOBS", AND WHERE A USER'
S TERMINAL.IS THE JOB'S "CONTROLLING TER
MINAL". SOME MAINFRAME SYSTEMS ALLOW US
ERS TO."ASSIGN" ANOTHER TERMINAL LINE ON
THE SAME MACHINE AS AN EXTERNAL INPUT/O
UTPUT.DEVICE..MAINFRAME OPERATING SYSTEM
TERMINAL DRIVERS USUALLY TREAT A JOB'S
CONTROLLING.TERMINAL SPECIALLY. FULL DU
PLEX SYSTEMS ECHO INCOMING CHARACTERS ON
THE.CONTROLLING TERMINAL, BUT NOT ON AN
ASSIGNED LINE. SYSTEM COMMAND INTERPRE
TERS.OR USER PROCESSES MIGHT TAKE SPECIA
L ACTION ON CERTAIN CHARACTERS ON THE.CO
NTROLLING LINE, BUT NOT ON AN ASSIGNED L
INE (FOR INSTANCE, CONTROL-C UNDER.CP/M
OR MOST DEC OPERATING SYSTEMS). MESSAGE
S SENT TO A JOB'S CONTROLLING.TERMINAL F
ROM OTHER JOBS COULD INTERFERE WITH TRAN
SMISSION OF DATA. THE.ABILITY OF A SYST
EM TO TEST FOR THE AVAILABILITY OF INPUT
ON A SERIAL LINE.MIGHT DEPEND ON WHETHE
R THE LINE IS THE JOB'S CONTROLLING TERM
INAL OR AN.ASSIGNED DEVICE; CP/M AND IBM
VM/370 ARE EXAMPLES OF SUCH SYSTEMS. CP
/M CAN.TEST FOR DATA ONLY AT THE CONSOLE
, VM CAN TEST ANYWHERE BUT THE CONSOLE..
.OUTPUT TO A JOB'S CONTROLLING TERMINAL
MAY BE REFORMATTED BY THE OPERATING.SYST
EM: CONTROL CHARACTERS MAY BE TRANSLATED
TO PRINTABLE EQUIVALENTS, LOWER.CASE LE
TTERS SPECIALLY FLAGGED OR TRANSLATED TO
UPPER CASE (OR VICE VERSA),.TABS EXPAND
ED TO SPACES. IN ADDITION, BASED ON THE
TERMINAL'S DECLARED "WIDTH".AND "LENGTH
", LONG LINES MIGHT BE "WRAPPED AROUND"
OR TRUNCATED, FORMFEEDS.TRANSLATED TO A
SERIES OF LINEFEEDS, AND THE SYSTEM MAY
WANT TO PAUSE AT THE.END OF EACH SCREENF
UL OF OUTPUT. INPUT FROM A JOB'S CONTRO
LLING TERMINAL MAY.ALSO BE HANDLED SPECI
ALLY: LOWER CASE LETTERS MAY BE CONVERTE
D TO UPPER CASE,.LINEFEED MAY BE SUPPLIE
D WHEN CARRIAGE RETURN IS TYPED, CONTROL
CHARACTERS MAY.INVOKE SPECIAL FUNCTIONS
LIKE LINE EDITING OR PROGRAM INTERRUPTI
ON..THE DECSYSTEM-20 IS AN EXAMPLE OF A
COMPUTER WHERE ANY OF THESE MIGHT HAPPEN
..THE MORAL HERE IS THAT CARE MUST BE TA
KEN TO DISABLE SPECIAL HANDLING OF A.MAI
NFRAME JOB'S CONTROLLING TERMINAL WHEN I
T IS TO BE A VEHICLE FOR INTER-.PROCESSO
R COMMUNICATION. BUT SOME SYSTEMS SIMPL
Y DO NOT ALLOW CERTAIN OF THESE.FEATURES
TO BE DISABLED, SO FILE TRANSFER PROTOC
OLS MUST BE DESIGNED AROUND.THEM...LINE
ACCESS..LINE ACCESS CAN BE EITHER FULL O
R HALF DUPLEX. IF FULL DUPLEX, TRANSMISS
ION CAN.OCCUR IN BOTH DIRECTIONS AT ONCE
. IF HALF DUPLEX, THE TWO SIDES MUST TAK
E TURNS.SENDING, EACH SIGNALING THE OTHE
R WHEN THE LINE IS FREE; DATA SENT OUT O
F TURN.IS DISCARDED, OR IT CAN CAUSE A B
REAK IN SYNCHRONIZATION. ON MAINFRAMES,
THE.HOST ECHOES CHARACTERS TYPED AT THE
TERMINAL IN FULL DUPLEX, BUT NOT IN HAL
F.DUPLEX. NATURALLY, ECHOING IS UNDESIRA
BLE DURING FILE TRANSFER. FULL DUPLEX.SY
STEMS CAN USUALLY ACCOMMODATE HALF DUPLE
X COMMUNICATION, BUT NOT VICE VERSA..IBM
MAINFRAMES ARE THE MOST PREVALENT HALF
DUPLEX SYSTEMS...BUFFERING AND FLOW CONT
ROL..SOME SYSTEMS CANNOT HANDLE SUSTAINE
D BURSTS OF INPUT ON A TELECOMMUNICATION
S.LINE; THE INPUT BUFFER CAN FILL UP FAS
TER THAN IT CAN BE EMPTIED, ESPECIALLY A
T.HIGH LINE SPEEDS. SOME SYSTEMS ATTEMP
T TO BUFFER "TYPEAHEAD" (UNREQUESTED.INP
UT), WHILE OTHERS DISCARD IT. THOSE THA
T BUFFER TYPEAHEAD MAY OR MAY NOT.PROVID
E A MECHANISM TO TEST OR CLEAR THE BUFFE
R..SYSTEMS MAY TRY TO REGULATE HOW FAST
CHARACTERS COME IN USING A FLOW CONTROL.
MECHANISM, EITHER IN THE DATA STREAM (XO
N/XOFF) OR IN PARALLEL TO IT (MODEM.CONT
ROL SIGNALS), BUT NO TWO SYSTEMS CAN BE
ASSUMED TO HONOR THE SAME.CONVENTIONS FO
R FLOW CONTROL, OR TO DO IT AT ALL..EVEN
WHEN FLOW CONTROL IS BEING DONE, THE CO
NTROL SIGNALS THEMSELVES ARE.SUBJECT TO
NOISE CORRUPTION. OUR EXPERIMENTS WITH S
EVERAL HOST COMPUTERS.REVEALED THAT A BU
RST OF MORE THAN ABOUT A LINE'S WORTH OF
CHARACTERS.(60-100 CHARACTERS) INTO A T
ERMINAL PORT AT MODERATE SPEED COULD RES
ULT IN.LOSS OF DATA - OR WORSE - ON SOME
HOSTS. FOR INSTANCE, THE COMMUNICATION
S.FRONT END OF THE DECSYSTEM-2060 IS DES
IGNED ON THE STATISTICAL ASSUMPTION THAT
.ALL TERMINAL INPUT COMES FROM HUMAN FIN
GERS, AND IT CANNOT ALLOCATE BUFFERS.FAS
T ENOUGH WHEN THIS ASSUMPTION IS VIOLATE
D BY SENDING CONTINUOUS DATA.SIMULTANEOU
SLY FROM SEVERAL MICROCOMPUTERS ATTACHED
TO TERMINAL PORTS...CHARACTER INTERPRET
ATION..SYSTEMS CAN DIFFER IN HOW THEY IN
TERPRET CHARACTERS THAT ARRIVE AT THE TE
RMINAL.PORT. A HOST CAN ACCEPT SOME CHAR
ACTERS AS SENT, IGNORE OTHERS, TRANSLATE
.OTHERS, TAKE SPECIAL ACTION ON OTHERS.
COMMUNICATIONS FRONT ENDS OR MULTI-.PLE
XERS MIGHT SWALLOW CERTAIN CHARACTERS (T
YPICALLY DC1, DC3) FOR FLOW CONTROL,.PAD
DING (NUL OR DEL), OR FOR TRANSFER OF CO
NTROL ("ESCAPE"). THE CHARACTERS.THAT TY
PICALLY TRIGGER SPECIAL BEHAVIOR ARE THE
ASCII CONTROL CHARACTERS, 0-31.AND 127.
FOR INSTANCE, OF THESE 33 CONTROL CHAR
ACTERS, 17 INVOKE SPECIAL.FUNCTIONS OF O
UR DECSYSTEM-20 COMMAND PROCESSOR. HOWE
VER, ALL HOSTS AND.COMMUNICATION PROCESS
ORS WE'VE ENCOUNTERED ALLOW ANY "PRINTAB
LE" CHARACTER.(ASCII 32-126) TO REACH AN
APPLICATION PROGRAM, EVEN THOUGH THE CH
ARACTER MAY.BE TRANSLATED TO A DIFFERENT
ENCODING, LIKE EBCDIC, FOR INTERNAL USE
...SOME OPERATING SYSTEMS ALLOW AN APPLI
CATION TO INPUT A CHARACTER AT A TIME,.O
THERS DELAY PASSING THE CHARACTERS TO TH
E PROGRAM UNTIL A "LOGICAL RECORD".HAS B
EEN DETECTED, USUALLY A SEQUENCE OF CHAR
ACTERS TERMINATED BY CARRIAGE.RETURN OR
LINEFEED. SOME RECORD ORIENTED SYSTEMS L
IKE IBM VM/370 DISCARD THE.TERMINATOR, O
THERS KEEP IT. AND THERE ARE DIFFERENT W
AYS OF KEEPING IT - UNIX.TRANSLATES CARR
IAGE RETURN INTO LINEFEED; MOST DEC OPER
ATING SYSTEMS KEEP THE.CARRIAGE RETURN B
UT ALSO ADD A LINEFEED...TIMING OUT..HOS
TS MAY OR MAY NOT HAVE THE ABILITY TO "T
IME OUT". WHEN EXCHANGING MESSAGES.WITH
ANOTHER COMPUTER, IT IS DESIRABLE TO BE
ABLE TO ISSUE AN INPUT REQUEST.WITHOUT
WAITING FOREVER SHOULD THE INCOMING DATA
BE LOST. A LOST MESSAGE COULD.RESULT IN
A PROTOCOL "DEADLOCK" IN WHICH ONE SYST
EM IS WAITING FOREVER FOR THE.MESSAGE WH
ILE THE OTHER WAITS FOR A RESPONSE. SOM
E SYSTEMS CAN SET TIMER.INTERRUPTS TO AL
LOW ESCAPE FROM POTENTIALLY BLOCKING OPE
RATIONS; OTHERS,.INCLUDING MANY MICROCOM
PUTERS, CAN NOT DO SO. WHEN TIMEOUTS AR
E NOT POSSIBLE,.THEY MAY BE SIMULATED BY
SLEEP-AND-TEST OR LOOP-AND-TEST OPERATI
ONS, OR DEAD-.LOCKED SYSTEMS MAY BE AWAK
ENED BY MANUAL INTERVENTION...FILE ORGAN
IZATION..SOME COMPUTERS STORE ALL FILES
IN A UNIFORM WAY, SUCH AS THE LINEAR STR
EAM OF.BYTES THAT IS A UNIX FILE. OTHER
COMPUTERS MAY HAVE MORE COMPLICATED OR.D
IVERSE FILE ORGANIZATIONS AND ACCESS MET
HODS: RECORD-ORIENTED STORAGE WITH.ITS M
ANY VARIATIONS, EXEMPLIFIED IN IBM OS/36
0 OR DEC RMS. EVEN SIMPLE.MICROCOMPUTERS
CAN PRESENT COMPLICATIONS WHEN FILES AR
E TREATED AS UNIFORM.DATA TO BE TRANSFER
RED; FOR INSTANCE UNDER CP/M, THE ENDS O
F BINARY AND TEXT.FILES ARE DETERMINED D
IFFERENTLY. A MAJOR QUESTION IN ANY OPE
RATING SYSTEM IS.WHETHER A FILE IS SPECI
FIED SUFFICIENTLY BY ITS CONTENTS AND IT
S NAME, OR IF.ADDITIONAL EXTERNAL INFORM
ATION IS REQUIRED TO MAKE THE FILE VALID
. A SIMPLE.GENERALIZED FILE TRANSFER FAC
ILITY CAN BE EXPECTED TO TRANSMIT A FILE
'S NAME.AND CONTENTS, BUT NOT EVERY CONC
EIVABLE ATTRIBUTE A FILE MIGHT POSSESS..
.DESIGNERS OF EXPENSIVE NETWORKS HAVE GO
NE TO GREAT LENGTHS TO PASS FILE.ATTRIBU
TES ALONG WHEN TRANSFERRING FILES BETWEE
N UNLIKE SYSTEMS. FOR INSTANCE,.THE DEC
NET DATA ACCESS PROTOCOL -DAP SUPPORTS 4
2 DIFFERENT "GENERIC SYSTEM.CAPABILITIES
" (LIKE WHETHER FILES CAN BE PREALLOCATE
D, APPENDED TO, ACCESSED.RANDOMLY, ETC),
8 DATA TYPES (ASCII, EBCDIC, EXECUTABLE
, ETC), 4 ORGANIZATIONS.(SEQUENTIAL, REL
ATIVE, INDEXED, HASHED), 5 RECORD FORMAT
S (FIXED, VARIABLE,.ETC), 8 RECORD ATTRI
BUTES (FOR FORMAT CONTROL), 14 FILE ALLO
CATION ATTRIBUTES.(BYTE SIZE, RECORD SIZ
E, BLOCK SIZE, ETC), 28 ACCESS OPTIONS (
SUPERSEDE,.UPDATE, APPEND, REWIND, ETC),
26 DEVICE CHARACTERISTICS (TERMINAL, DI
RECTORY.STRUCTURED, SHARED, SPOOLED, ETC
), VARIOUS ACCESS OPTIONS (NEW, OLD, REN
AME,.PASSWORD, ETC), IN ADDITION TO THE
BETTER KNOWN FILE ATTRIBUTES LIKE NAME,.
CREATION DATE, PROTECTION CODE, AND SO O
N. ALL THIS WAS DEEMED NECESSARY EVEN.W
HEN THE DESIGNERS HAD ONLY A SMALL NUMBE
R OF MACHINES TO WORRY ABOUT, ALL FROM.A
SINGLE VENDOR..THE ARPA NETWORK, WHICH
ATTEMPTS TO PROVIDE SERVICES FOR MANY MO
RE MACHINES.FROM MANY VENDORS, MAKES SOM
E SIMPLIFYING ASSUMPTIONS AND SETS SOME
RESTRIC-.TIONS IN ITS FILE TRANSFER PROT
OCOL (FTP). ALL FILES ARE FORCED INTO CE
RTAIN.CATEGORIES WITH RESPECT TO ENCODIN
G (ASCII, EBCDIC, IMAGE), RECORD FORMAT.
CONTROL, BYTE SIZE, FILE STRUCTURE (RECO
RD OR STREAM), AND IT IS GENERALLY.LEFT
TO THE HOST FTP IMPLEMENTATION TO DO THE
NECESSARY TRANSFORMATIONS..NO PARTICULA
R PROVISION IS MADE, OR CAN BE MADE, TO
ENSURE THAT SUCH TRANS-.FORMATIONS ARE I
NVERTIBLE..DECNET IS ABLE TO PROVIDE INV
ERTIBILITY FOR OPERATING SYSTEMS LIKE VM
S OR RSX,.WHICH CAN STORE THE NECESSARY
FILE ATTRIBUTES ALONG WITH THE FILE. BU
T SIMPLER.FILE SYSTEMS, LIKE THOSE OF TO
PS-10 OR TOPS-20, CAN LOSE VITAL INFORMA
TION.ABOUT INCOMING FILES. FOR INSTANCE,
IF VMS REQUIRES SOME TYPE OF FILE TO HA
VE A.SPECIFIC BLOCKSIZE, WHILE TOPS-20 H
AS NO CONCEPT OF BLOCK SIZE, THEN THE BL
OCK-.SIZE WILL BE LOST UPON TRANSFER FRO
M VMS TO TOPS-20 AND CANNOT BE RESTORED.
AUTOMATICALLY WHEN THE FILE IS SENT BACK
, LEAVING THE RESULT POTENTIALLY.UNUSABL
E...INVERTIBILITY IS A MAJOR PROBLEM, WI
TH NO SIMPLE SOLUTION. FORTUNATELY, MOST
.FILE TRANSFER BETWEEN UNLIKE SYSTEMS IN
VOLVES ONLY TEXTUAL INFORMATION - DATA,.
DOCUMENTS, PROGRAM SOURCE - WHICH IS SEQ
UENTIAL IN ORGANIZATION, AND FOR WHICH.A
NY REQUIRED TRANSFORMATIONS (E.G. BLOCKE
D TO STREAM, EBCDIC TO ASCII) ARE.SIMPLE
AND NOT DEPENDENT ON ANY SPECIAL FILE A
TTRIBUTES...IN FACT, INVERTABILITY CAN B
E ACHIEVED IF THAT IS THE PRIMARY GOAL O
F A FILE.TRANSFER PROTOCOL. ALL THE EXTE
RNAL ATTRIBUTES OF A FILE CAN BE ENCODED
AND.INCLUDED WITH THE CONTENTS OF THE F
ILE TO BE STORED ON THE REMOTE SYSTEM..F
OR UNLIKE SYSTEMS, THIS CAN RENDER THE F
ILE LESS THAN USEFUL ON THE TARGET.SYSTE
M, BUT ALLOWS IT TO BE RESTORED CORRECTL
Y UPON RETURN. HOWEVER, IT IS.MORE COMM
ONLY DESIRED THAT TEXTUAL FILES REMAIN I
NTELLIGIBLE WHEN TRANSFERRED.TO A FOREIG
N SYSTEM, EVEN IF TRANSFORMATIONS MUST B
E MADE. TO ALLOW THE.NECESSARY TRANSFORM
ATIONS TO TAKE PLACE ON TEXTUAL FILES BE
TWEEN UNLIKE.SYSTEMS, THERE MUST BE A ST
ANDARD WAY OF REPRESENTING THESE FILES D
URING.TRANSMISSION...BINARY FILES VERSUS
PARITY..EACH ASCII CHARACTER IS REPRESE
NTED BY A STRING OF 7 BITS. PRINTABLE AS
CII.FILES CAN BE TRANSMITTED IN A STRAIG
HTFORWARD FASHION, BECAUSE ASCII.TRANSMI
SSION IS DESIGNED FOR THEM: A SERIAL STR
EAM OF 8-BIT CHARACTERS, 7 BITS.FOR DATA
AND 1 FOR PARITY, FRAMED BY START AND S
TOP BITS FOR THE BENEFIT OF.THE HARDWARE
. THE PARITY BIT IS ADDED AS A CHECK ON
THE INTEGRITY OF A.CHARACTER; SOME SYSTE
MS ALWAYS TRANSMIT PARITY, OTHERS INSIST
ON PARITY FOR.INCOMING CHARACTERS, STIL
L OTHERS IGNORE THE PARITY BIT FOR COMMU
NICATION.PURPOSES AND PASS IT ALONG TO T
HE SOFTWARE, WHILE STILL OTHERS DISCARD
IT.ALTOGETHER. IN ADDITION, COMMUNICATI
ON FRONT ENDS OR COMMON CARRIERS MIGHT.U
SURP THE PARITY BIT, REGARDLESS OF WHAT
THE SYSTEM ITSELF MAY DO...COMPUTER FILE
SYSTEMS GENERALLY STORE AN ASCII FILE A
S A SEQUENCE OF EITHER.7-BIT OR 8-BIT BY
TES. 8-BIT BYTES ARE MORE COMMON, IN WH
ICH THE 8TH BIT OF.EACH BYTE IS SUPERFLU
OUS. BESIDES FILES COMPOSED OF ASCII CH
ARACTERS,.HOWEVER, COMPUTERS ALSO HAVE "
BINARY" FILES, IN WHICH EVERY BIT IS MEA
NINGFUL;.EXAMPLES INCLUDE EXECUTABLE "CO
RE IMAGES" OF PROGRAMS, NUMBERS STORED I
N."INTERNAL FORMAT", DATABASES WITH IMBE
DDED POINTERS. SUCH BINARY DATA MUST BE
.MAPPED TO ASCII CHARACTERS FOR TRANSMIS
SION OVER SERIAL LINES. WHEN TWO.SYSTEM
S ALLOW THE USER-LEVEL SOFTWARE TO CONTR
OL THE PARITY BIT, THE ANSI.STANDARDS MA
Y BE STRETCHED TO PERMIT THE TRANSMISSIO
N OF 8 DATA BITS PER.CHARACTER, WHICH CO
RRESPONDS TO THE BYTE SIZE OF MOST MACHI
NES. BUT SINCE NOT.ALL COMPUTERS ALLOW T
HIS FLEXIBILITY, THE ABILITY TO TRANSFER
BINARY DATA IN.THIS FASHION CANNOT BE A
SSUMED...SOFTWARE..FINALLY, SYSTEMS DIFF
ER IN THE APPLICATION SOFTWARE THEY HAVE
. IN PARTICULAR,.NO SYSTEM CAN BE ASSUME
D TO HAVE A PARTICULAR PROGRAMMING LANGU
AGE. EVEN.WIDESPREAD LANGUAGES LIKE FORT
RAN AND BASIC MAY BE LACKING FROM SOME C
OMPUTERS,.EITHER BECAUSE THEY HAVE NOT B
EEN IMPLEMENTED, OR BECAUSE THEY ARE PRO
PRIETARY.AND HAVE NOT BEEN PURCHASED. EV
EN WHEN TWO DIFFERENT SYSTEMS SUPPORT TH
E SAME.LANGUAGE, IT IS UNREALISTIC TO EX
PECT THE TWO IMPLEMENTATIONS OF THE LANG
UAGE.TO BE TOTALLY COMPATIBLE. A GENERAL
PURPOSE FILE TRANSFER PROTOCOL SHOULD N
OT.BE GEARED TOWARDS THE FEATURES ANY PA
RTICULAR LANGUAGE.....KERMIT.======..OUR
PROTOCOL, WHICH WE CALL KERMIT, ADDRESS
ES THE PROBLEMS OUTLINED ABOVE BY.SETTIN
G CERTAIN MINIMAL STANDARDS FOR TRANSMIS
SION, AND PROVIDING A MAPPING.BETWEEN DI
SK STORAGE ORGANIZATION, MACHINE WORD AN
D BYTE SIZE, AND THE TRANS-.MISSION MEDI
UM...KERMIT HAS THE FOLLOWING CHARACTERI
STICS:..COMMUNICATION TAKES PLACE OVER O
RDINARY TERMINAL CONNECTIONS..COMMUNICAT
ION IS HALF DUPLEX. THIS ALLOWS BOTH FUL
L AND HALF DUPLEX SYSTEMS TO.PARTICIPATE
, AND IT ELIMINATES THE ECHOING THAT WOU
LD OTHERWISE OCCUR FOR.CHARACTERS ARRIVI
NG AT A HOST JOB'S CONTROLLING TERMINAL.
.THE PACKET LENGTH IS VARIABLE, BUT THE
MAXIMUM IS 96 CHARACTERS SO THAT MOST.HO
STS CAN TAKE PACKETS IN WITHOUT BUFFERIN
G PROBLEMS..PACKETS ARE SENT IN ALTERNAT
E DIRECTIONS; A REPLY IS REQUIRED FOR EA
CH PACKET..THIS IS TO ALLOW HALF DUPLEX
SYSTEMS TO PARTICIPATE, AND TO PREVENT B
UFFER.OVERRUNS THAT WOULD OCCUR ON SOME
SYSTEMS IF PACKETS WERE SENT BACK TO BAC
K..A TIMEOUT FACILITY, WHEN AVAILABLE, A
LLOWS TRANSMISSION TO RESUME AFTER LOST.
PACKETS..ALL TRANSMISSION IS IN ASCII.
ANY NON-ASCII HOSTS ARE RESPONSIBLE FOR.
CONVERSION. ASCII CONTROL CHARACTERS AR
E PREFIXED AND THEN CONVERTED TO.PRINTAB
LE CHARACTERS DURING TRANSMISSION TO ENS
URE THAT THEY ARRIVE AS SENT..A SINGLE A
SCII CONTROL CHARACTER (NORMALLY SOH) IS
USED TO MARK THE BEGINNING.OF A PACKET.
.BINARY FILES CAN BE TRANSMITTED BY A SI
MILAR PREFIX SCHEME, OR BY USE OF THE.PA
RITY BIT WHEN BOTH SIDES HAVE CONTROL OF
IT..LOGICAL RECORDS (LINES) IN TEXTUAL
FILES ARE TERMINATED DURING TRANSMISSION
.WITH QUOTED CARRIAGE-RETURN/LINEFEED SE
QUENCES, WHICH ARE TRANSPARENT TO THE.PR
OTOCOL AND MAY APPEAR ANYWHERE IN A PACK
ET. SYSTEMS THAT DELIMIT RECORDS.IN OTH
ER WAYS ARE RESPONSIBLE FOR CONVERSION,
IF THEY DESIRE THE DISTINCTION.BETWEEN R
ECORDS TO BE PRESERVED ACROSS UNLIKE SYS
TEMS..ONLY A FILE'S NAME AND CONTENTS AR
E TRANSMITTED - NO ATTRIBUTES. IT IS TH
E.USER'S RESPONSIBILITY TO SEE THAT THE
FILE IS STORED CORRECTLY ON THE TARGET.S
YSTEM. WITHIN THIS FRAMEWORK, INVERTIBL
E TRANSFER OF TEXT FILES CAN BE.ASSURED,
BUT INVERTIBLE TRANSFER OF NON-@]TEXT F
ILES DEPENDS ON THE.CAPABILITIES OF THE
PARTICULAR IMPLEMENTATIONS OF KERMIT AND
THE HOST OPERATING.SYSTEMS...KERMIT HAS
NO SPECIAL KNOWLEDGE OF THE HOST ON THE
OTHER SIDE. NO ATTEMPT.IS MADE TO "INT
EGRATE" THE TWO SIDES. RATHER, KERMIT I
S DESIGNED TO WORK MORE.OR LESS UNIFORML
Y ON ALL SYSTEMS. KERMIT NEED NOT BE WRI
TTEN IN ANY PARTICULAR.LANGUAGE. IT IS N
OT A PORTABLE PROGRAM, BUT A PORTABLE PR
OTOCOL....THUS KERMIT ACCOMMODATES ITSEL
F TO MANY SYSTEMS BY CONFORMING TO A COM
MON.SUBSET OF THEIR FEATURES. BUT THE R
ESULTING SIMPLICITY AND GENERALITY ALLOW
.KERMIT ON ANY MACHINE TO COMMUNICATE WI
TH KERMIT ON ANY OTHER MACHINE, MICRO-.T
O-MAINFRAME, MICRO-TO-MICRO, MAINFRAME-T
O-MAINFRAME. THE BACK-AND-FORTH.EXCHANG
E OF PACKETS KEEPS THE TWO SIDES SYNCHRO
NIZED; THE PROTOCOL CAN BE.CALLED "ASYNC
HRONOUS" ONLY BECAUSE THE COMMUNICATION
HARDWARE ITSELF OPERATES.ASYNCHRONOUSLY.
AS FAR AS THE USER IS CONCERNED, KERMIT
IS A DO-IT-YOURSELF.OPERATION. FOR INST
ANCE, TO TRANSFER FILES BETWEEN YOUR MIC
RO AND A MAINFRAME,.YOU WOULD RUN KERMIT
ON YOUR MICRO, PUT KERMIT INTO TERMINAL
EMULATION MODE,.WHICH "CONNECTS" YOU TO
THE MAINFRAME, LOG IN AND RUN KERMIT ON
THE MAINFRAME,.THEN "ESCAPE" BACK TO TH
E MICRO AND ISSUE COMMANDS TO THE MICRO'
S KERMIT TO.SEND OR FETCH THE DESIRED FI
LES. ANY INCONVENIENCE IMPLICIT IN THIS
PROCEDURE.IS A CONSEQUENCE OF THE POWER
IT GIVES THE ORDINARY USER TO ESTABLISH
RELIABLE.CONNECTIONS BETWEEN COMPUTERS T
HAT COULD NOT OTHERWISE BE CONNECTED...P
ACKETS.=======..KERMIT PACKETS NEED TO C
ONTAIN THE DATA THAT IS BEING TRANSFERRE
D, PLUS MINIMUM.INFORMATION TO ASSURE (W
ITH HIGH PROBABILITY) THAT THE EXPECTED
DATA ARRIVES.COMPLETELY AND CORRECTLY.
SEVERAL ISSUES COME UP WHEN DESIGNING TH
E PACKET.LAYOUT: HOW TO REPRESENT DATA,
HOW TO DELIMIT FIELDS WITHIN THE PACKET,
HOW TO.DELIMIT THE PACKET ITSELF, HOW T
O ARRANGE THE FIELDS WITHIN THE PACKET.
SINCE.THE TRANSMISSION MEDIUM ITSELF IS
CHARACTER-ORIENTED, IT IS NOT FEASIBLE
TO.TRANSMIT BIT STRINGS OF ARBITRARY LEN
GTH, AS DO THE BIT-ORIENTED PROTOCOLS.LI
KE HDLC AND SDLC. THEREFORE THE SMALLES
T UNIT OF INFORMATION IN A PACKET.MUST B
E THE ASCII CHARACTER. AS WE WILL SEE,
THIS PRECLUDES SOME TECHNIQUES.THAT ARE
USED WITH OTHER COMMUNICATION MEDIA...CO
NTROL FIELDS..MOST POPULAR PROTOCOL DEFI
NITIONS VIEW THE PACKET AS LAYERS OF INF
ORMATION,.WHICH PASS THROUGH A HIERARCHY
OF PROTOCOL LEVELS, EACH LEVEL ADDING I
TS OWN.INFORMATION AT THE ENDS OF AN OUT
BOUND PACKET OR STRIPPING ITS INFORMATIO
N FROM.THE ENDS OF AN INCOMING PACKET, A
ND THEN PASSING THE RESULT ALONG TO THE
NEXT.LEVEL IN THE HIERARCHY. THE FIELDS
FOR EACH LAYER MUST BE ARRANGED SO THAT
THEY.CAN BE FOUND, IDENTIFIED, AND INTER
PRETED CORRECTLY AT THE APPROPRIATE LEVE
L...SINCE KERMIT PACKETS ARE SHORT, IT I
S IMPORTANT TO MINIMIZE THE AMOUNT OF.CO
NTROL INFORMATION PER PACKET. IT WOULD
BE CONVENIENT TO LIMIT THE CONTROL.FIELD
S TO ONE CHARACTER EACH. SINCE WE HAVE
95 PRINTABLE CHARACTERS TO WORK.WITH (12
8 ASCII CHARACTERS, LESS DEL AND THE 32
CONTROL CHARACTERS), WE CAN.REPRESENT VA
LUES FROM 0 TO 94 WITH A SINGLE CHARACTE
R...THE PACKET SEQUENCE NUMBER IS USED T
O DETECT MISSING OR DUPLICATE PACKETS..I
T IS UNLIKELY THAT A LARGE NUMBER OF PAC
KETS COULD BE LOST, ESPECIALLY SINCE.PAC
KET N IS ACKNOWLEDGED BEFORE PACKET N+1
IS SENT. SO THE SEQUENCE NUMBER CAN.BE A
SMALL QUANTITY, WHICH "WRAPS AROUND" TO
ITS MINIMUM VALUE WHEN IT EXCEEDS.A SPE
CIFIED MAXIMUM VALUE. TO PREVENT LONG PA
CKETS, A SMALL MAXIMUM LENGTH CAN.BE ENF
ORCED BY SPECIFYING THE PACKET LENGTH WI
TH A SINGLE CHARACTER; SINCE.THERE ARE 9
5 PRINTABLE ASCII CHARACTERS, THIS WOULD
BE THE MAXIMUM LENGTH,.DEPENDING ON HOW
WE COUNT THE CONTROL FIELDS...THE CHECK
SUM CAN BE OF FIXED LENGTH. THE ACTUAL
LENGTH DEPENDS ON THE DESIRED.BALANCE BE
TWEEN AND EFFICIENCY AND ERROR DETECTION
...THE PACKET LENGTH AND CHECKSUM ACT TO
GETHER TO DETECT CORRUPTED, MISSING, OR.
EXTRA CHARACTERS. THESE ARE THE ESSENTI
AL FIELDS FOR PROMOTING ERROR-FREE.TRANS
MISSION. BUT SO FAR, WE'VE ONLY CONSIDER
ED PACKETS THAT CARRY ACTUAL FILE.DATA;
WE WILL ALSO REQUIRE SPECIAL PACKETS COM
POSED ONLY OF CONTROL INFORMA-.TION, FOR
INSTANCE TO TELL THE REMOTE HOST THE NA
ME OF THE FILE THAT IS ABOUT.TO COME, OR
TO TELL IT THAT THE TRANSMISSION IS COM
PLETE. THIS CAN BE.ACCOMPLISHED WITH A
PACKET TYPE FIELD. THE NUMBER OF FUNCTI
ONS WE NEED TO.SPECIFY IN THIS FIELD IS
SMALL, SO A SINGLE CHARACTER CAN SUFFICE
HERE TOO...PACKET FRAMING..WE CHOOSE TO
MARK THE BEGINNING OF A PACKET WITH A D
ISTINGUISHED START.CHARACTER, SOH (START
OF HEADER, ASCII 1, CONTROL-A). THIS C
HARACTER CANNOT.APPEAR ANYWHERE ELSE WIT
HIN THE PACKET. SOH WAS CHOSEN BECAUSE,
UNLIKE MOST.OTHER CONTROL CHARACTERS, I
T IS GENERALLY ACCEPTED UPON INPUT AT A
JOB'S.CONTROLLING TERMINAL AS A DATA CHA
RACTER, RATHER THAN AN INTERRUPT OR BREA
K.CHARACTER ON MOST MAINFRAMES. THIS IS
PROBABLY NO ACCIDENT, SINCE IT WAS.ORIG
INALLY INTENDED FOR THIS USE BY THE DESI
GNERS OF THE ASCII ALPHABET..SHOULD A SY
STEM BE INCAPABLE OF SENDING OR RECEIVIN
G SOH, IT IS POSSIBLE TO.REDEFINE THE ST
ART-OF-PACKET CHARACTER TO BE ANY OTHER
CONTROL CHARACTER; THE.TWO SIDES NEED NO
T USE THE SAME ONE. THERE ARE THREE PRIN
CIPAL OPTIONS FOR.RECOGNIZING THE END OF
A PACKET:..A FIXED LENGTH, A DISTINGUIS
HED PACKET-END CHARACTER, AND A LENGTH F
IELD..THERE ARE ARGUMENTS FOR AND AGAINS
T EACH INVOLVING WHAT HAPPENS WHEN CHARA
C-.TERS, PARTICULARLY A LENGTH OR TERMIN
ATOR, IS LOST OR GARBLED, WHICH WILL BE.
MENTIONED LATER. KERMIT USES A LENGTH F
IELD. TO TAKE IN A PACKET, A KERMIT.PROG
RAM GETS CHARACTERS FROM THE LINE UNTIL
IT ENCOUNTERS THE SOH. THE NEXT.CHARACT
ER IS THE LENGTH; KERMIT READS AND DECOD
ES THE LENGTH AND THEN READS.THAT MANY S
UBSEQUENT CHARACTERS TO COMPLETE THE PAC
KET. IF ANOTHER SOH IS.ENCOUNTERED BEFO
RE THE COUNT IS EXHAUSTED, THE CURRENT P
ACKET IS FORGOTTEN.AND A NEW ONE IS STAR
TED. THIS STRATAGY ALLOWS ARBITRARY AMO
UNTS OF NOISE.TO BE GENERATED SPONTANEOU
SLY BETWEEN PACKETS WITHOUT INTERFERING
WITH THE.PROTOCOL...ENCODING..WHEN TRANS
MITTING TEXTUAL DATA, KERMIT TERMINATES
LOGICAL RECORDS WITH.CARRIAGE-RETURN LIN
EFEED COMBINATIONS (CRLFS). ON RECORD O
RIENTED SYSTEMS,.TRAILING BLANKS OR LENG
TH FIELDS ARE REMOVED AND A CRLF APPENDE
D TO OUTBOUND.RECORDS, WITH THE INVERSE
OPERATION PERFORMED ON INCOMING RECORDS.
ON STREAM.ORIENTED SYSTEMS, INCOMING C
RLFS MAY BE TRANSLATED TO SOME OTHER TER
MINATOR..FILES, OF COURSE, NEED NOT HAVE
LOGICAL RECORDS, IN WHICH CASE RECORD P
RO-.CESSING CAN BE SKIPPED ALTOGETHER, A
ND THE FILE CAN BE TREATED AS A LONG STR
ING.OF BYTES. THIS IS KNOWN AS "IMAGE" T
RANSFER, AND CAN ALSO BE USED BETWEEN LI
KE.SYSTEMS WHERE NO TRANSFORMATIONS ARE
NECESSARY. IN ORDER TO MAKE EACH CHARACT
ER.IN THE PACKET PRINTABLE, KERMIT "QUOT
ES" ANY UNPRINTABLE CHARACTER BY TRANS-.
FORMING IT TO A PRINTABLE ONE AND PRECED
ES IT WITH A SPECIAL PREFIX CHARACTER..T
HE PREFIX IS NORMALLY "#"; THE TRANSFORM
ATION IS DONE BY COMPLEMENTING BIT 6.(AD
DING OR SUBTRACTING 64). THUS CONTROL-A
BECOMES "#A", CONTROL-Z BECOMES."#Z", U
S (CONTROL-UNDERSCORE ON MOST TERMINALS)
BECOMES "#_". THE PREFIX.CHARACTER IS
ALSO USED TO QUOTE ITSELF: "##". UPON I
NPUT, THE REVERSE.TRANSFORMATION IS PERF
ORMED. PRINTABLE CHARACTERS ARE NOT TRA
NSFORMED..THE ASSUMPTION IS THAT MOST FI
LES TO BE TRANSFERRED ARE PRINTABLE, AND
.PRINTABLE FILES CONTAIN RELATIVELY FEW
CONTROL CHARACTERS; WHEN THIS IS TRUE,.T
HE CHARACTER STREAM IS NOT SIGNIFICANTLY
LENGTHENED BY QUOTING. FOR BINARY.FILE
S, THE AVERAGE QUOTING OVERHEAD WILL BE
26.6% IF ALL BIT PATTERNS ARE.EQUALLY LI
KELY, SINCE THE CHARACTERS THAT MUST BE
QUOTED (THE CONTROL CHARAC-.TERS, PLUS D
EL, AND "#" ITSELF) COMPRISE 26.6% OF TH
E ASCII ALPHABET...KERMIT ALSO PROVIDES
A SCHEME FOR INDICATING THE STATUS OF TH
E 8TH BIT WHEN.TRANSFERRING BINARY FILES
BETWEEN SYSTEMS THAT MUST USE THE 8TH B
IT FOR PARITY..A BYTE WHOSE 8TH BIT IS S
ET IS PRECEDED BY ANOTHER SPECIAL QUOTIN
G CHARACTER,."&". IF THE LOW-ORDER 7 BI
TS COINCIDE WITH AN ASCII CONTROL CHARAC
TER, THEN.CONTROL-CHARACTER QUOTING IS A
LSO DONE. FOR INSTANCE, THE BYTE 100000
01 WOULD.BE TRANSMITTED AS "&#A". THE "
&" CHARACTER ITSELF CAN BE INCLUDED AS D
ATA BY.QUOTING IT (#&), AND THE CONTROL-
QUOTE CHARACTER MAY HAVE ITS 8TH BIT SET
.(&##). 8TH-BIT QUOTING IS ONLY DONE WHE
N NECESSARY; IF BOTH SIDES CAN CONTROL.T
HE PARITY BIT, THEN ITS VALUE IS PRESERV
ED DURING TRANSMISSION. IF THE 8TH.BIT
IS SET RANDOMLY ON BINARY FILES, THEN 8T
H-BIT QUOTING WILL ADD 50% CHARAC-.TER O
VERHEAD. FOR SOME KINDS OF BINARY DATA,
IT COULD BE LESS; FOR INSTANCE,.POSITIVE
BINARY NUMBERS IN 2'S COMPLEMENT NOTATI
ON DO NOT TO HAVE THEIR HIGH-.ORDER BITS
SET, IN WHICH CASE AT LEAST ONE BYTE PE
R WORD WILL NOT BE QUOTED..A THIRD KIND
OF "QUOTING" IMPLEMENTS RUDIMENTARY DATA
COMPRESSION. AT LOW.SPEEDS, THE BOTTLE
NECK IN FILE TRANSMISSION IS LIKELY TO B
E THE LINE ITSELF,.SO ANY MEASURE THAT C
AN CUT DOWN ON USE OF THE LINE WOULD BE
WELCOME. THE.SPECIAL PREFIX CHARACTER "
>" INDICATES THAT THE NEXT CHARACTER IS
A REPEAT.COUNT (A SINGLE CHARACTER, ENCO
DED PRINTABLY) AND THAT THE CHARACTER AF
TER THAT.(WHICH MAY ALSO HAVE CONTROL OR
8TH-BIT PREFIXES) IS REPEATED SO MANY T
IMES..FOR INSTANCE ">=A" INDICATES A SER
IES OF 93 LETTER A'S; ">H&#B" INDICATES
A.SERIES OF 40 CONTROL-B'S WITH THE PARI
TY BIT SET. THE REPEAT COUNT PREFIX.ITS
ELF CAN BE INCLUDED AS TEXT BY QUOTING I
T WITH "#"..TO KEEP THE PROTOCOL SIMPLE,
NO OTHER TRANSFORMATIONS ARE DONE. AT
THIS POINT,.HOWEVER, IT MIGHT BE WORTH M
ENTIONING SOME THINGS WE DID NOT DO TO T
HE DATA:.
===..FANCY DAT
A COMPRESSION. IF THE DATA IS KNOWN TO
BE (OR RESEMBLE) ENGLISH TEXT,.A HUFFMAN
ENCODING BASED ON THE FREQUENCY OF CHAR
ACTERS IN ENGLISH TEXT COULD.BE USED. A
HUFFMAN CODE RESEMBLES MORSE CODE, WHIC
H HAS VARIABLE LENGTH.CHARACTERS WHOSE B
OUNDARIES CAN ALWAYS BE DISTINGUISHED.
THE MORE FREQUENT THE.CHARACTER, THE SHO
RTER THE BIT STRING TO REPRESENT IT. OF
COURSE, THIS SCHEME.CAN BACKFIRE IF THE
CHARACTER DISTRIBUTION OF THE DATA IS V
ERY DIFFERENT FROM.THE ONE ASSUMED. IN A
NY CASE, VARIABLE LENGTH CHARACTERS AND
ASCII TRANSMISSION.DON'T MIX WELL...ERRO
R CORRECTING CODES. TECHNIQUES, SUCH AS
HAMMING CODES, EXIST FOR DETECTING.AND C
ORRECTING ERRORS ON A PER-CHARACTER BASI
S. THESE ARE EXPENSIVE IN.RESOURCES AND
COMPLEX TO PROGRAM. KERMIT USES PER-PACK
ET BLOCK CHECK.TECHNIQUES, WHICH ARE EXP
LAINED BELOW...NIBBLE ENCODING. TO CIRC
UMVENT PROBLEMS WITH CONTROL AND 8-BIT C
HARACTERS, IT.WOULD HAVE BEEN POSSIBLE T
O DIVIDE EVERY CHARACTER INTO TWO 4-BIT
"NIBBLES",.SENDING EACH NIBBLE AS A PRIN
TABLE CHARACTER (E.G. A HEXADECIMAL DIGI
T). THE.CHARACTER OVERHEAD CAUSED BY THI
S SCHEME WOULD WOULD ALWAYS BE 100%. BUT
IT.WOULD BE AN EASY WAY TO TRANSFER BIN
ARY FILES....ERROR DETECTION..CHARACTER
PARITY AND HAMMING CODES ARE FORMS OF "V
ERTICAL REDUNDANCY CHECKS".(VRCS), FORME
D BY COMBINING ALL THE BITS OF A CHARACT
ER IN ONE WAY OR ANOTHER..THE OTHER KIND
OF CHECK THAT CAN BE USED IS THE "LONGI
TUDINAL REDUNDANCY CHECK".(LRC), WHICH P
RODUCES A "BLOCK CHECK CHARACTER" FORMED
BY SOME COMBINATION OF.EACH CHARACTER W
ITHIN A SEQUENCE. THE SENDING SIDE COMP
UTES THE LRC AND SENDS.IT WITH THE PACKE
T; THE RECEIVING SIDE RECOMPUTES IT FOR
COMPARISON. THERE ARE.VARIOUS FORMS OF L
RCS. ONE FORM PRODUCES A "COLUMN PARITY
" CHARACTER, OR."LOGICAL SUM", WHOSE BIT
S ARE THE EXCLUSIVE-ORS OF THE CORRESPON
DING BITS OF.THE DATA CHARACTERS. ANOTH
ER IS THE "CHECKSUM" WHICH IS THE ARITHM
ETIC SUM OF.ALL THE CHARACTERS IN THE SE
QUENCE, INTERPRETED NUMERICALLY. ANOTHE
R IS THE."CYCLIC REDUNDANCY CHECK" (CRC)
, WHICH PASSES THE CHARACTERS THROUGH WH
AT.AMOUNTS TO A SHIFT REGISTER WITH IMBE
DDED FEEDBACK LOOPS, PRODUCING A BLOCK.C
HECK IN WHICH EACH BIT IS EFFECTED IN MA
NY WAYS BY THE PRECEDING CHARACTERS..ALL
OF THESE TECHNIQUES WILL CATCH SINGLE-B
IT ERRORS. THEY VARY IN THEIR.ABILITY T
O DETECT OTHER KINDS OF ERRORS. FOR INS
TANCE, A DOUBLE-BIT COLUMN.ERROR WILL AL
WAYS GO UNDETECTED WITH COLUMN PARITY, S
INCE THE RESULT OF XORING.ANY TWO BITS T
OGETHER IS THE SAME AS XORING THEIR COMP
LEMENTS, WHEREAS HALF THE.POSSIBLE DOUBL
E BIT ERRORS CAN BE CAUGHT BY ADDITION B
ECAUSE OF THE CARRY INTO.THE NEXT BIT PO
SITION. CRC DOES EVEN BETTER BY RIPPLIN
G THE EFFECT OF A DATA.BIT MULTIPLY THRO
UGH THE BLOCK CHECK CHARACTER, BUT THE M
ETHOD IS COMPLEX, AND.A SOFTWARE IMPLEME
NTATION OF CRC CAN BE INSCRUTABLE. STAND
ARD, BASE-LEVEL.KERMIT EMPLOYS A SINGLE-
CHARACTER ARITHMETIC CHECKSUM, WHICH IS
SIMPLE TO.PROGRAM, IS LOW IN OVERHEAD, A
ND HAS PROVEN QUITE ADEQUATE IN PRACTICE
. THE.SUM IS FORMED BY ADDING TOGETHER T
HE ASCII VALUES OF EACH CHARACTER IN THE
.PACKET EXCEPT THE SOH AND THE CHECKSUM
ITSELF, AND INCLUDING ANY QUOTING.CHARAC
TERS. EVEN NON-ASCII HOSTS MUST DO THIS
CALCULATION IN ASCII. THE.RESULT CAN AP
PROACH 12,000 IN THE WORST CASE. THE BI
NARY REPRESENTATION OF.THIS NUMBER IS 10
111011100000, WHICH IS 14 BITS LONG. TH
IS IS MUCH MORE THAN.ONE CHARACTER'S WOR
TH OF BITS, BUT WE CAN MAKE THE OBSERVAT
ION THAT EVERY.CHARACTER INCLUDED IN THE
SUM HAS CONTRIBUTED TO THE LOW ORDER 7
BITS, SO WE.CAN DISCARD SOME HIGH ORDER
BITS AND STILL HAVE A VIABLE VALIDITY CH
ECK...THE KERMIT PROTOCOL ALSO ALLOWS OT
HER BLOCK CHECK OPTIONS, INCLUDING A TWO
-.CHARACTER CHECKSUM AND A THREE-CHARACT
ER 16-BIT CRC. THE TWO-CHARACTER.CHECKS
UM IS SIMPLY THE LOW ORDER 12 BITS OF TH
E ARITHMETIC SUM, BROKEN INTO.TWO PRINTA
BLE CHARACTERS. THE CRC SEQUENCE IS FOR
MED FROM THE 16-BIT QUANTITY.GENERATED B
Y THE CCITT-RECOMMENDED POLYNOMIAL X(16)
+X(12)+X(5)+1 WHICH IS ALSO.USED IN SOME
FORM WITH OTHER POPULAR TRANSMISSION TE
CHNIQUES, LIKE ISO HDLC AND.IBM SDLC. TH
E HIGH ORDER 4 BITS OF THE CRC GO INTO T
HE FIRST CHARACTER, THE.MIDDLE 6 INTO TH
E SECOND, AND THE LOW ORDER 6 INTO THE T
HIRD. SOME CARE MUST BE.TAKEN IN THE FOR
MATION OF THE SINGLE-CHARACTER BLOCK CHE
CK. SINCE IT MUST BE.EXPRESSED AS A SING
LE PRINTABLE CHARACTER, VALUES OF THE HI
GH ORDER DATA BITS.MAY BE LOST, WHICH CO
ULD RESULT IN UNDETECTED ERRORS, ESPECIA
LLY WHEN TRANS-.FERRING BINARY FILES. T
HEREFORE, WE EXTRACT THE 7TH AND 8TH BIT
S OF THE SUM.AND ADD THEM BACK TO THE LO
W ORDER BITS; IF THE ARITHMETIC SUM OF A
LL THE.CHARACTERS IS S, THEN THE VALUE O
F THE SINGLE-CHARACTER KERMIT CHECKSUM I
S.GIVEN BY.. (S + S AND 300)/100)) AND
77..(NUMBERS ARE IN OCTAL NOTATION). TH
IS ENSURES THAT THE CHECKSUM, TERSE THOU
GH.IT IS, REFLECTS EVERY BIT FROM EVERY
CHARACTER IN THE PACKET...THE PROBABILIT
Y THAT AN ERROR WILL NOT BE CAUGHT BY A
CORRECTLY TRANSMITTED.ARITHMETIC CHECKSU
M IS THE RATIO OF THE NUMBER OF POSSIBLE
ERRORS THAT CANCEL.EACH OTHER OUT TO TH
E TOTAL NUMBER OF POSSIBLE ERRORS, WHICH
WORKS OUT TO BE.SOMETHING LIKE 1/2 N, W
HERE N IS THE NUMBER OF BITS IN THE CHEC
KSUM, ASSUMING.ALL ERRORS ARE EQUALLY LI
KELY. THIS IS 1/64 FOR THE SINGLE CHARA
CTER CHECKSUM,.AND 1/4096 FOR THE 2-CHAR
ACTER CHECKSUM. BUT THE PROBABILITY THA
T ERRORS WILL.GO UNDETECTED BY THIS METH
OD (UNDER REAL CONDITIONS) CANNOT BE EAS
ILY DERIVED,.BECAUSE ALL KINDS OF ERRORS
ARE NOT EQUALLY LIKELY. A 16-BIT CRC W
ILL DETECT.ALL SINGLE AND DOUBLE BIT ERR
ORS, ALL MESSAGES WITH AN ODD NUMBER OF
BITS IN.ERROR, ALL ERROR BURSTS SHORTER
THAN 16 BITS, AND BETTER THAN 99.99% OF
LONGER.BURSTS. THESE PROBABILITIES ALL A
SSUME, OF COURSE, THAT THE BLOCK CHECK H
AS.BEEN IDENTIFIED CORRECTLY, I.E. THAT
THE LENGTH FIELD POINTS TO IT, AND THAT
NO.INTERVENING CHARACTERS HAVE BEEN LOST
OR SPURIOUSLY ADDED...A FINAL NOTE ON P
ARITY - A PARITY BIT ON EACH CHARACTER C
OMBINED WITH A LOGICAL.SUM OF ALL THE CH
ARACTERS (VRC AND LRC) WOULD ALLOW DETEC
TION AND CORRECTION OF.SINGLE-BIT ERRORS
WITHOUT RETRANSMISSION BY PINPOINTING T
HE "ROW" AND "COLUMN".OF THE BAD BIT. B
UT CONTROL OF THE PARITY BIT CANNOT BE A
CHIEVED ON EVERY.SYSTEM, SO WE USE THE P
ARITY BIT FOR BINARY DATA WHEN WE CAN, O
R SURRENDER IT.TO THE COMMUNICATION HARD
WARE IF WE MUST. IF WE HAVE USE OF THE
8TH BIT FOR.DATA, THEN IT IS FIGURED INT
O THE BLOCK CHECK; IF WE DO NOT, THEN IT
MUST BE.OMITTED FROM THE BLOCK CHECK IN
CASE IT HAS BEEN CHANGED BY AGENTS BEYO
ND THE.KNOWLEDGE OR CONTROL OF THE KERMI
T PROGRAM....PACKET LAYOUT..KERMIT PACKE
TS HAVE THE FORMAT:..+------+-----------
+-----------+------+------------+-------
+.! MARK ! CHAR(LEN) ! CHAR(SEQ) 1 TYPE
! DATA ! CHECK !.+------+---------
--+-----------+------+------------+-----
--+.! ! !
! !.!
! +-- (APPLICATION) --+
!.! !
! !.!
+-------------- (SESSION) ------+
!.!
!.+----------
----------------------- (DATA LINK) ----
--------+..WHERE ALL FIELDS CONSIST OF A
SCII CHARACTERS, AND THE CHAR FUNCTION C
ONVERTS A.NUMBER IN THE RANGE 0-94 TO A
PRINTABLE ASCII CHARACTER BY ADDING 32.
IN TERMS.OF THE ISO NETWORK REFERENCE MO
DEL , 8-BIT BYTES ARE PRESENTED TO THE K
ERMIT.PROGRAM BY THE HARDWARE AND OPERAT
ING SYSTEM SOFTWARE COMPRISING THE PHYSI
CAL.LINK LAYER. CORRECT TRANSMISSION IS
ENSURED BY THE PACKET-LEVEL ROUTINES THA
T.IMPLEMENT THE DATA LINK LAYER USING TH
E OUTER "SKIN" OF THE PACKET - THE MARK,
.LEN, AND CHECK FIELDS. THE NETWORK AND
TRANSPORT LAYERS ARE MOOT, SINCE KERMIT
.IS A POINT-TO-POINT AFFAIR, IN WHICH TH
E USER PERSONALLY MAKES ALL THE REQUIRED
.CONNECTIONS. THE SESSION LAYER IS RESP
ONSIBLE FOR REQUESTING RETRANSMISSION OF
.MISSING PACKETS OR IGNORING REDUNDANT O
NES, BASED ON THE SEQ FIELD; THE PRESEN-
.TATION LAYER IS RESPONSIBLE FOR ANY DAT
A CONVERSIONS (EBCDIC/ASCII, INSERTION.O
R STRIPPING OF CRLFS, ETC). FINALLY, TH
E REMAINDER OF THE PACKET, THE TYPE.AND
DATA FIELDS, ARE THE PROVINCE OF THE APP
LICATION LAYER; OUR APPLICATION, OF.COUR
SE, IS FILE TRANSFER. IN ANY PARTICULAR
IMPLEMENTATION, HOWEVER, THE.ORGANIZATI
ON OF THE PROGRAM MAY NOT STRICTLY FOLLO
W THIS MODEL. FOR INSTANCE,.SINCE TRANS
MISSION IS ALWAYS IN STREAM ASCII, IBM I
MPLEMENTATIONS MUST CONVERT.FROM EBCDIC
AND INSERT CRLFS BEFORE CHECKSUM COMPUTA
TION...THE FIELDS OF A KERMIT PACKET ARE
AS FOLLOWS:..START-OF-PACKET CHARACTER,
NORMALLY SOH (ASCII 1)..THE NUMBER OF A
SCII CHARACTERS, INCLUDING QUOTING CHARA
CTERS AND THE CHECKSUM,.WITHIN THE PACKE
T THAT FOLLOW THIS FIELD, IN OTHER WORDS
THE PACKET LENGTH.MINUS TWO. SINCE THIS
NUMBER IS EXPRESSED AS A SINGLE CHARACT
ER VIA THE CHAR.FUNCTION, PACKET CHARACT
ER COUNTS OF 0 TO 94 ARE PERMITTED, AND
96 IS THE.MAXIMUM TOTAL PACKET LENGTH...
THE PACKET SEQUENCE NUMBER. THE SEQUENC
E NUMBERS "WRAPS AROUND" TO 0 AFTER.EACH
GROUP OF 64 PACKETS...THE PACKET TYPE,
A SINGLE PRINTABLE ASCII CHARACTER, ONE
OF THE FOLLOWING:..DATA.ACKNOWLEDGE (ACK
).NEGATIVE ACKNOWLEDGE (NAK).SEND INITIA
TE (SEND-INIT).RECEIVE INITIATE.BREAK TR
ANSMISSION (EOT).FILE HEADER.END OF FILE
(EOF).ERROR..GENERIC COMMAND. A SINGLE
CHARACTER IN THE DATA FIELD, POSSIBLY F
OLLOWED BY.OPERANDS, REQUESTS HOST-INDEP
ENDENT REMOTE EXECUTION THE SPECIFIED CO
MMAND:..LOGOUT, BYE..FINISH, BUT DON'T L
OGOUT..DIRECTORY QUERY (FOLLOWED BY OPTI
ONAL FILE SPECIFICATION)..DISK USAGE QUE
RY..ERASE (FOLLOWED BY FILE SPECIFICATIO
N)..TYPE (FOLLOWED BY FILE SPECIFICATION
)..QUERY SERVER STATUS..AND OTHERS...HOS
T COMMAND. THE DATA FIELD CONTAINS A ST
RING TO BE EXECUTED AS A SYSTEM.DEPENDEN
T (LITERAL) COMMAND BY THE HOST...TEXT D
ISPLAY HEADER, TO INDICATE THE ARRIVAL O
F TEXT TO BE DISPLAYED ON THE.SCREEN, FO
R INSTANCE AS THE RESULT OF A GENERIC OR
HOST COMMAND EXECUTED AT THE.OTHER END.
OPERATION IS EXACTLY LIKE A FILE TRANSF
ER...DATA THE "CONTENTS" OF THE PACKET
, IF ANY CONTENTS ARE REQUIRED IN THE GI
VEN.TYPE OF PACKET, INTERPRETED ACCORDIN
G TO THE PACKET TYPE. NONPRINTABLE ASCI
I.CHARACTERS ARE PREFIXED WITH QUOTE CHA
RACTERS AND THEN "UNCONTROLLIFIED"..CHAR
ACTERS WITH THE 8TH BIT SET MAY ALSO BE
PREFIXED, AND A REPEATED CHARACTER.CAN B
E PREFIXED BY A COUNT. A PREFIXED SEQUEN
CE MAY NOT BE BROKEN ACROSS.PACKETS...CH
ECK THE BLOCK CHECK SEQUENCE, BASED ON
ALL THE CHARACTERS IN THE PACKET.BETWEEN
, BUT NOT INCLUDING, THE MARK AND THE CH
ECK ITSELF, ONE, TWO, OR THREE.CHARACTER
S IN LENGTH AS DESCRIBED ABOVE, EACH CHA
RACTER TRANSFORMED BY CHAR..NORMALLY, TH
E SINGLE-CHARACTER CHECKSUM IS USED...TH
E PACKET MAY BE FOLLOWED BY ANY LINE TER
MINATOR REQUIRED BY THE HOST,.CARRIAGE R
ETURN (ASCII 15) BY DEFAULT. LINE TERMI
NATORS ARE NOT PART OF THE.PACKET, AND A
RE NOT INCLUDED IN THE COUNT OR CHECKSUM
. TERMINATORS ARE NOT.NECESSARY TO THE
PROTOCOL, AND ARE INVISIBLE TO IT, AS AR
E ANY CHARACTERS THAT.MAY APPEAR BETWEEN
PACKETS. IF A HOST CANNOT DO SINGLE CH
ARACTER INPUT FROM A.TTY LINE, THEN A TE
RMINATOR WILL BE REQUIRED FOR THAT HOST.
HERE ARE SOME.SAMPLE KERMIT DATA PACKET
S:..^AE"D NO CELESTIAL BODY HAS REQUIR
ED J.^AE#DAS MUCH LABOR FOR THE STUDY OF
ITS#.^AE$D#M#JMOTION AS THE MOON. SINC
E CLAA.^AE%DIRAULT (1747), WHO INDICATED
A WAY7.^AE&D OF#M#JCONSTRUCTING A THEOR
Y CONTA5..THE "^A" REPRESENTS THE SOH (O
R CONTROL-A) CHARACTER. IN THE FINAL PAC
KET.SHOWN, "E" IS THE LENGTH. THE ASCII
VALUE OF THE "E" CHARACTER IS 69, LESS
32.(THE UNCHAR TRANSFORMATION, WHICH IS
THE OPPOSITE OF CHAR) GIVES A LENGTH OF.
37. THE NEXT CHARACTER TELLS THE PACKET
SEQUENCE NUMBER, IN THIS CASE 6 ("&" IS.
ASCII 38). THE NEXT IS THE PACKET TYPE "
D" FOR DATA. THE NEXT CHARACTERS,."@Q<
OF#M#JCONSTRUCTING A THEORY CONTA>", FOR
M THE DATA; NOTE THE PREFIXED.CARRIAGE R
ETURN AND LINE FEED. THE FINAL CHARACTER
, "5" IS THE CHECKSUM,.WHICH REPRESENTS
THE NUMBER 21 (ALL NUMBERS IN THIS PARAG
RAPH ARE IN DECIMAL)....EFFECTS OF PACKE
T CORRUPTION..WHAT ARE THE CONSEQUENCES
OF TRANSMISSION ERRORS IN THE VARIOUS FI
ELDS? IF.THE SOH IS GARBLED, THE PACKET
WILL BE TREATED AS INTERPACKET GARBAGE,
AND.LOST. IF ANY OTHER CHARACTER WITHIN
THE PACKET IS GARBLED INTO SOH, THE CUR
RENT.PACKET WILL BE DISCARDED, AND A NEW
(SPURIOUS) PACKET DETECTED. IF THE LENG
TH.IS GARBLED INTO A SMALLER NUMBER, THE
N A CHARACTER FROM THE DATA FIELD WILL B
E.MISINTERPRETED AS THE CHECKSUM; IF LAR
GER, THEN THE PROGRAM WILL PROBABLY.BECO
ME STUCK TRYING TO INPUT CHARACTERS THAT
WILL NOT BE SENT UNTIL ONE SIDE OR.THE
OTHER TIMES OUT AND RETRANSMITS. IF THE
SEQUENCE NUMBER, TYPE, ANY OF THE.DATA
CHARACTERS, OR THE CHECKSUM ITSELF IS GA
RBLED, THE CHECKSUM SHOULD BE.WRONG. IF
CHARACTERS ARE LOST, THERE WILL MOST LIK
ELY BE A TIMEOUT. IF NOISE.CHARACTERS AR
E SPONTANEOUSLY GENERATED, THEY WILL BE
IGNORED IF THEY ARE.BETWEEN PACKETS, OR
WILL CAUSE THE WRONG CHARACTER TO BE INT
ERPRETED AS THE.CHECKSUM IF THEY COME DU
RING PACKET TRANSMISSION. MOST KINDS OF
ERRORS ARE.CAUGHT BY THE CHECKSUM COMPAR
ISON, AND ARE HANDLED BY IMMEDIATE RETRA
NSMISSION..TIMEOUTS ARE MORE COSTLY BECA
USE THE LINE SITS IDLE FOR THE TIMEOUT P
ERIOD..THE PACKET DESIGN MINIMIZES THE N
ECESSITY FOR TIMEOUTS DUE TO PACKET.CORR
UPTION: THE ONLY FIELDS THAT CAN BE CORR
UPTED TO CAUSE A TIMEOUT ARE THE.SOH AND
THE PACKET LENGTH, AND THE LATTER ONLY
HALF THE TIME. LOST CHARACTERS,.HOWEVER,
CAN PRODUCE THE SAME EFFECT (AS THEY WO
ULD WITH A FIXED-LENGTH BLOCK.PROTOCOL).
HAD A DISTINGUISHED END-OF-PACKET CHAR
ACTER BEEN USED RATHER THAN A.LENGTH FIE
LD, THEN THERE WOULD BE A TIMEOUT EVERY
TIME IT WAS CORRUPTED. IT IS.ALWAYS BET
TER TO RETRANSMIT IMMEDIATELY THAN TO TI
ME OUT....PROTOCOL.========..THE KERMIT
PROTOCOL CAN BE DESCRIBED AS A SET OF ST
ATES AND A SET OF.TRANSITIONS THAT DEFIN
E, FOR A GIVEN EVENT, WHAT ACTION TO TAK
E AND WHAT NEW.STATE TO CHANGE TO. THE I
NHERENT SIMPLICITY OF THE DESIGN, PARTIC
ULARLY THE.REQUIREMENT THAT EACH PACKET
MUST BE ACKNOWLEDGED, REDUCES THE NUMBER
OF STATES.AND ACTIONS, AND THE AMOUNT O
F STATE INFORMATION THAT MUST BE MAINTAI
NED, TO A.MINIMUM. HERE IS A SIMPLIFIED
VERSION OF A STATE DIAGRAM FOR KERMIT RE
CEIVING A.FILE:..
+--------------+.
! RECEIVE INIT !.
+--------------+.
!.
! (GET SEND IN
IT PACKET).
!. (GET EOT PACKET)
V. +----
----------+. (DONE) <------------------
! RECEIVE FILE !<---------------+.
+--------------+
!.
! !.
! (GET
FILE ! (GET EOF PACKET).
! HEAD
ER PACKET) !.
V !
. +----------
----+ !.
+------>! RECEIVE DATA !-------------
---+. ! +------
--------+. !
!. !
! (GET DATA PACKET).
! !.
+---------------+..FOR SIMPLICITY, SOM
E TRANSITIONS ARE NOT SHOWN IN THE DIAGR
AM:..IF IN ANY STATE A BAD PACKET IS REC
EIVED OR A TIMEOUT OCCURS, A NULL TRANSI
TION.BACK TO THE SAME STATE OCCURS, WITH
A NAK FOR THE EXPECTED PACKET. IN ANY S
TATE.AN ERROR MAY OCCUR THAT CAN CAUSE T
HE TRANSFER TO TERMINATE. FOR INSTANCE,
THE.TARGET DISK MIGHT FILL UP. THE SID
E THAT ENCOUNTERED THE ERROR SENDS AN ER
ROR.PACKET, CONTAINING AN INFORMATIVE ER
ROR MESSAGE, AND QUITS. UPON RECEIPT OF
THE.ERROR PACKET, THE OTHER SIDE DISPLAY
S THE MESSAGE ON THE SCREEN (IF IT IS IN
.CONTROL OF THE SCREEN) AND ALSO QUITS.
ACTIONS THAT ARE TAKEN ON EACH.TRANSITIO
N, SUCH AS OPENING A FILE WHEN A FILE HE
ADER PACKET IS RECEIVED, ARE.NOT SHOWN;
IN PARTICULAR EACH PACKET SUCCESSFULLY R
ECEIVED IS ACK'D...THE RECEIVER STARTS O
UT IN RECEIVE INIT STATE AND WAITS FOR T
HE OTHER SIDE TO.SEND A SEND-INIT PACKET
. IF ANY OTHER KIND OF PACKET IS RECEIVE
D, OR THE SEND-.INIT DOES NOT ARRIVE WIT
HIN THE TIMEOUT INTERVAL, A NAK IS SENT.
TIMEOUTS OR.NAKS CAN OCCUR UP TO A THRE
SHOLD WHICH, WHEN EXCEEDED FOR A PARTICU
LAR PACKET,.CAUSES THE PROTOCOL TO ASSUM
E THAT THE CONNECTION HAS BECOME UNUSABL
E, AND TO.GIVE UP...AFTER THE SEND-INIT
ARRIVES, THE STATE BECOMES RECEIVE FILE;
KERMIT WAITS FOR.A FILE HEADER PACKET C
ONTAINING THE NAME OF THE FILE WHICH IS
TO COME. WHEN.THE FILE HEADER ARRIVES,
KERMIT OPENS A NEW FILE USING THE NAME P
ROVIDED.(PERHAPS TRANSFORMED TO SUIT LOC
AL NAMING CONVENTIONS, OR TO AVOID A NAM
E.COLLISION), AND SWITCHES TO RECEIVE DA
TA STATE. KERMIT THEN RECEIVES THE.CONT
ENTS OF THE FILE, UNTIL AN EOF (END OF F
ILE) PACKET ARRIVES. AT THAT POINT.KERM
IT SWITCHES BACK TO RECEIVE FILE STATE.
IF ANOTHER FILE IS TO BE SENT,.ANOTHER
FILE HEADER PACKET WILL FOLLOW, OTHERWIS
E AN EOT (END OF TRANSMISSION).PACKET WI
LL TERMINATE THE TRANSFER. THE DISTINCT
ION BETWEEN EOF AND EOT, PLUS.THE FILE H
EADER ITSELF, ALLOWS FILES TO BE SENT IN
GROUPS. EOF MARKS THE END.OF A FILE, E
OT MARKS THE END OF A GROUP. THIS DISTIN
CTION ALSO ALLOWS THE TWO.SIDES TO DISCO
NNECT CLEANLY: THE EOF MUST BE ACK'D BEF
ORE THE SENDER WILL.BELIEVE THE FILE HAS
BEEN TRANSMITTED CORRECTLY; THE EOT WIL
L FOLLOW, BUT IF.THE ACK WHICH IS SENT I
N RESPONSE IS LOST, NO HARM WILL BE DONE
SINCE BOTH.SIDES ARE TERMINATING ANYWAY
. THE STATE TRANSITIONS FOR A SENDING KE
RMIT ARE.SIMILAR. IN EACH STATE, INSTEAD
OF WAITING FOR PARTICULAR PACKET TYPES,
KERMIT.SENDS THE APPROPRIATE PACKET AND
WAITS FOR AN ACK. IF THE ACK DOES NOT
ARRIVE.WITHIN THE ALLOTTED TIME, OR A NA
K APPEARS INSTEAD OF AN ACK, THE SAME PA
CKET.IS RETRANSMITTED. A SEND OPERATION
BEGINS WITH A SEND-INIT PACKET, INCLUDE
S.ONE OR MORE FILES, EACH STARTING WITH
A FILE HEADER, FOLLOWED BY ONE OR MORE.D
ATA PACKETS, FOLLOWED BY EOF. WHEN ALL
THE SPECIFIED FILES HAVE BEEN SENT, AN.E
OT PACKET CLOSES THE CONNECTION AND TERM
INATES THE OPERATION...
+-----------+.
! SEND INIT !.
+-----------+.
!.
! (GET GOOD ACK).
!.
(NO MORE FILES TO SEND) V. +-
---------+ +-----------+.
! SEND EOT !<-------------! SEND FILE !<
---------------+. +----------+
+-----------+ !.
!
!.
! (GOOD ACK) ! (EOF).
!
!.
V !.
+-----------+
!. +--
---->! SEND DATA !----------------+.
! +-----------+.
! !.
! ! (GOOD
ACK). !
!. +---------------+
...BASE-LEVEL KERMIT PROVIDES THAT DURIN
G ANY PARTICULAR TRANSACTION, THE SENDER
.IS THE "MASTER" AND THE RECEIVER IS THE
"SLAVE". THESE ROLES MAY BE REVERSED.I
N THE NEXT TRANSACTION; ANY KERMIT IMPLE
MENTATION IS CAPABLE OF ACTING AS.EITHER
MASTER OR SLAVE. IN ADDITION, MAINFRAM
E IMPLEMENTATIONS MAY ALSO BE PUT.IN A K
IND OF PERMANENT SLAVE, OR "SERVER", MOD
E IN WHICH ALL COMMANDS COME IN.COMMAND
PACKETS FROM THE MASTER, OR "USER" KERMI
T..INITIAL CONNECTION..TO ALLOW A DIVERS
E GROUP OF COMPUTERS TO COMMUNICATE WITH
ONE ANOTHER, AN.EXCHANGE TAKES PLACES D
URING INITIAL CONNECTION IN WHICH THE TW
O SIDES."CONFIGURE" EACH OTHER. THE SEN
DING KERMIT INCLUDES SETUP PARAMETERS IN
.ITS SEND-INIT PACKET AND THE RECEIVING
KERMIT RESPONDS WITH AN ACK PACKET.CONTA
INING THE CORRESPONDING PARAMETERS AS TH
EY APPLY TO ITSELF. THE DATA.FIELD OF T
HE SEND-INIT PACKET LOOKS LIKE THIS:..1
2 3 4 5 6
7 8 9 10.+------+------+-
-----+------+------+------+------+------
+------+-------------.! MAXL ! TIME ! NP
AD ! PADC ! EOL ! QCTL ! QBIN ! CHKT !
REPT ! CAPAS....+------+------+------+-
-----+------+------+------+------+------
+-------------..THE FIELDS ARE AS FOLLOW
S (THE FIRST AND SECOND PERSON "I" AND "
YOU" ARE USED.TO DISTINGUISH THE TWO SID
ES). FIELDS ARE ENCODED PRINTABLY USING
THE CHAR.FUNCTION (ASCII VALUE + 32) UN
LESS INDICATED OTHERWISE...MAXL THE MAX
IMUM LENGTH PACKET I WANT TO RECEIVE, A
NUMBER UP TO 94. YOU.RESPOND WITH THE MA
XIMUM YOU WANT ME TO SEND. THIS ALLOWS S
YSTEMS TO ADJUST TO.EACH OTHER'S BUFFER
SIZES, OR TO THE CONDITION OF THE TRANSM
ISSION MEDIUM...TIME THE NUMBER OF SECO
NDS AFTER WHICH I WANT YOU TO TIME ME OU
T WHILE WAITING.FOR A PACKET FROM ME. Y
OU RESPOND WITH THE AMOUNT OF TIME I SHO
ULD WAIT FOR.PACKETS FROM YOU. THIS ALL
OWS THE TWO SIDES TO ACCOMMODATE TO DIFF
ERENT LINE.SPEEDS OR OTHER FACTORS THAT
COULD CAUSE TIMING PROBLEMS...NPAD THE
NUMBER OF PADDING CHARACTERS I WANT TO P
RECEDE EACH INCOMING PACKET;.YOU RESPOND
IN KIND. PADDING MAY BE NECESSARY FOR
A HALF DUPLEX SYSTEM THAT.REQUIRES SOME
TIME TO CHANGE THE DIRECTION OF TRANSMIS
SION...PADC THE CONTROL CHARACTER I NEE
D FOR PADDING, IF ANY, XOR'D WITH 100 OC
TAL.TO MAKE IT PRINTABLE. YOU RESPOND I
N KIND. NORMALLY NUL (ASCII 0), SOME.SY
STEMS USE DEL (ASCII 177). THIS FIELD I
S IGNORED IF THE VALUE NPAD IS ZERO...EO
L THE CHARACTER I NEED TO TERMINATE AN
INCOMING PACKET, IF ANY. YOU RESPOND.IN
KIND. MOST SYSTEMS THAT REQUIRE A LINE
TERMINATOR FOR TERMINAL INPUT ACCEPT.CAR
RIAGE RETURN FOR THIS PURPOSE. (CAN YOU
SEE THE CATCH-22 HERE?)..QCTL THE PRIN
TABLE ASCII CHARACTER I WILL USE TO QUOT
E CONTROL CHARACTERS AND.PREFIX CHARACTE
RS, NORMALLY "#". YOU RESPOND WITH THE O
NE YOU WILL USE...QBIN THE PRINTABLE AS
CII CHARACTER I WANT TO USE TO QUOTE CHA
RACTERS WHICH.HAVE THE 8TH BIT SET, FOR
TRANSMITTING BINARY FILES WHEN ONE OR BO
TH SYSTEMS.CANNOT USE THE PARITY BIT FOR
DATA. SINCE THIS KIND OF QUOTING INCRE
ASES BOTH.PROCESSOR AND TRANSMISSION OVE
RHEAD, IT IS NORMALLY TO BE AVOIDED...CH
KT CHECK TYPE, THE METHOD FOR DETECTING
ERRORS. "1" FOR SINGLE-CHARACTER.CHECKS
UM (THE NORMAL METHOD), "2" FOR TWO-CHAR
ACTER CHECKSUM, "3" FOR THREE-.CHARACTER
CRC-CCITT. IF YOUR RESPONSE AGREES, TH
E DESIGNATED METHOD WILL BE.USED; OTHERW
ISE THE SINGLE-CHARACTER CHECKSUM WILL B
E USED. OTHER CHECK TYPES.MAY ALSO BE A
DDED...REPT THE PREFIX CHARACTER I WILL
USE TO INDICATE A REPEATED CHARACTER. T
HIS.CAN BE ANY PRINTABLE CHARACTER OTHER
THAN BLANK (WHICH DENOTES NO REPEAT COU
NT.PREFIX), BUT ">" IS RECOMMENDED. IF
YOU DON'T RESPOND IDENTICALLY, REPEAT.CO
UNTS WILL NOT BE DONE. GROUPS OF 4 OR M
ORE IDENTICAL CHARACTERS MAY BE.TRANSMIT
TED MORE EFFICIENTLY USING A REPEAT COUN
T, THOUGH AN INDIVIDUAL.IMPLEMENTATION M
AY WISH TO SET A HIGHER THRESHHOLD...CAP
AS AN EXTENDABLE BIT MASK ENCODED PRINT
ABLY, TO INDICATE WHETHER CERTAIN.ADVANC
ED CAPABILITIES, SUCH AS FILE-ATTRIBUTE
PACKETS, ARE SUPPORTED...[RESERVED FIELD
S] THE NEXT FOUR FIELDS ARE RESERVED FO
R FUTURE USE. SITES.WISHING TO ADD THEIR
OWN PARAMETERS TO THE INITIAL CONNECTIO
N EXCHANGE SHOULD.START AT THE FIFTH FIE
LD AFTER THE CAPABILITY MASK IN ORDER TO
REMAIN.COMPATIBLE WITH OTHER KERMIT PRO
GRAMS....NATURALLY, THE THREE PREFIX CHA
RACTERS MUST BE DISTINCT AND SHOULD BE C
HOSEN TO.BE UNCOMMONLY USED PRINTABLE CH
ARACTERS, TO MINIMIZE FURTHER OVERHEAD F
ROM.HAVING TO PREFIX THEM WHEN THEY ARE
FOUND IN THE DATA...TRAILING FIELDS WITH
IN THE DATA FIELD MAY BE OMITTED, IN WHI
CH CASE THEY WILL.ASSUME APPROPRIATE DEF
AULTS. DEFAULTS FOR INTERMEDIATE FIELDS
CAN BE ELECTED.BY SETTING THOSE FIELDS
TO BLANK. EVERY PARAMETER HAS AN APPROP
RIATE DEFAULT,.AND IN FACT THE ENTIRE DA
TA FIELD OF THE SEND INIT PACKET OR ITS
ACK MAY BE.LEFT EMPTY TO ACCEPT ALL DEFA
ULTS. THE MORE EXOTIC PARAMATERS ARE AT
THE END,.AND REFLECT MORE RECENT DEVELO
PMENTS IN THE KERMIT PROTOCOL; EARLIER.I
MPLEMENTATIONS CAN STILL COMMUNICATE WIT
H NEWER ONES, SINCE THERE WILL NOT BE.AG
REEMENT TO USE THESE OPTIONS. THE SEND-I
NIT MECHANISM PRESERVES COMPATIBILITY.FR
OM THE VERY EARLIEST KERMIT TO THE VERY
NEWEST. THERE IS NO PROTRACTED.NEGOTIATI
ON; EVERYTHING MUST BE SETTLED IN A SING
LE EXCHANGE. SOME PARAMETERS,.HOWEVER,
ARE OUTSIDE THE SCOPE OF THIS EXCHANGE A
ND MUST BE SET EVEN BEFORE THE.VERY FIRS
T PACKET IS SENT. FOR INSTANCE, IF THE
RECEIVING COMPUTER CAN ONLY.READ CHARACT
ERS WITH ODD PARITY BUT THE SENDING COMP
UTER SENDS THEM WITH EVEN.PARITY, THE SE
ND-INIT PACKET WILL NEVER ARRIVE SUCCESS
FULLY. IN CASES LIKE.THIS, THE USER MAY
HAVE TO ISSUE SOME PRELIMINARY COMMANDS
TO INFORM ONE OR.BOTH KERMITS ABOUT THE
VAGARIES OF THE OTHER SYSTEM..ANOTHER EX
AMPLE IS THE PACKET TERMINATOR (EOL) ME
NTIONED ABOVE - IF THE.RECEIVING KERMIT
REQUIRES ONE THAT THE SENDING KERMIT DOE
SN'T KNOW ABOUT, THE.SEND-INIT WILL NEVE
R GET THROUGH...FOR THESE REASONS, MOST
IMPLEMENTATIONS OF KERMIT PROVIDE SET CO
MMANDS FOR ALL.THE PARAMETERS LISTED ABO
VE, AND SOME OTHERS AS WELL....RULES AND
HEURISTICS..DURING A FILE TRANSFER, ONE
KERMIT SENDS INFORMATION PACKETS - FILE
HEADERS,.DATA, AND SO FORTH, AND THE OT
HER KERMIT SENDS ONLY ACKS OR NAKS IN RE
SPONSE..THE MOST IMPORTANT RULE IN THE K
ERMIT PROTOCOL IS..1.) WAIT FOR A RESPO
NSE BEFORE SENDING THE NEXT PACKET..THIS
PREVENTS BUFFER OVERRUNS, AND ALLOWS PA
RTICIPATION BY HALF DUPLEX SYSTEMS..OF C
OURSE, KERMIT SHOULD NOT WAIT FOREVER; A
TIMEOUT SHOULD OCCUR AFTER A FEW.SECOND
S IF THE EXPECTED PACKET HAS NOT ARRIVED
. UPON TIMEOUT, A SENDING KERMIT.RETRAN
SMITS THE CURRENT PACKET; A RECEIVING KE
RMIT RE-ACKS THE CURRENT PACKET.OR NAKS
THE EXPECTED ONE..SOME INTERESTING HEURI
STICS ARE USED IN THE KERMIT PROTOCOL TO
BOOST EFFICIENCY.AND IMPROVE ERROR RECO
VERY. A NUMBER OF IMPORTANT RULES TAKE
CARE OF THE CASES.WHEN PACKETS ARE LOST
IN TRANSMISSION. THE FIRST CAN BE STATE
D AS..2.) A NAK FOR THE NEXT PACKET IMP
LIES AN ACK FOR THE CURRENT PACKET..A NA
K WITH PACKET NUMBER N+1 MEANS THE RECEI
VING KERMIT GOT PACKET N, SENT AN.ACK TH
AT WAS NEVER RECEIVED, AND NOT KNOWING T
HAT THE ACK DIDN'T GET THROUGH.(SINCE WE
DON'T ACK AN ACK), IS NOW WAITING FOR P
ACKET N+1, WHICH WAS NEVER.SENT. IN THI
S CASE, WE SIMPLY SEND PACKET N+1. AN IM
PORTANT EXCEPTION IS WHEN.THE MISSING AC
K IS FOR A SEND-INIT PACKET; DO YOU SEE
WHY? THE NEXT RULE,..3.) ACK AND DISCA
RD REDUNDANT PACKETS..HANDLES THE SITUAT
ION WHERE THE SAME PACKET ARRIVES AGAIN.
THE SENDING KERMIT.TIMED OUT WAITING F
OR AN ACK WHICH WAS SENT, BUT LOST, AND
RETRANSMITTED THE.PACKET. THE RECEIVER
MUST DISCARD THE REDUNDANT DATA AND ACK
THE PACKET AGAIN;.TO DO OTHERWISE COULD
HAVE UNDESIRABLE EFFECTS, LIKE ADDING TH
E SAME DATA TO A.FILE TWICE OR OPENING T
HE SAME FILE MULTIPLE TIMES. NOTE THAT T
HE SITUATION.RESULTING FROM A LOST ACK D
EPENDS UPON WHICH SIDE TIMES OUT FIRST..
.KERMIT MUST HANDLE ANOTHER SITUATION AR
ISING FROM POSSIBLE LOST PACKETS:..4.)
NAK THE EXPECTED COMMAND..THE POTENTIAL
PROBLEM OCCURS IN EITHER THE RECEIVE INI
T STATE OR WHEN A KERMIT.SERVER IS WAITI
NG FOR A COMMAND. IN EITHER CASE KERMIT
WON'T KNOW WHETHER.COMMUNICATION HAS BE
GUN IF THE OTHER SIDE'S INITIAL PACKET W
AS LOST. KERMIT.CAN'T ASSUME THE OTHER
SIDE WILL TIME OUT AND RETRANSMIT, SO IT
MUST CHECK.PERIODICALLY BY SENDING A NA
K FOR PACKET ZERO. IF KERMIT GETS NO RE
SPONSE IT.ASSUMES NOTHING HAS HAPPENED Y
ET AND GOES BACK TO SLEEP FOR A WHILE..B
UT SENDING PERIODIC NAKS OPENS THE DOOR
TO THE BUFFERING PROBLEM. SOME.SYSTEMS
BUFFER INPUT FOR A DEVICE; WHEN A PROGRA
M ISN'T LOOKING FOR INPUT SOME.OR ALL TH
E INPUT IS SAVED BY THE COMPUTER FOR FUT
URE REQUESTS. THIS CAN CAUSE.PROBLEMS W
HEN TALKING TO A KERMIT SERVER OR SENDIN
G A FILE TO A KERMIT IN.RECEIVE WAIT. IF
SOME TIME HAS ELAPSED SINCE ACTIVATING
THE REMOTE KERMIT AND.ESCAPING BACK AND
STARTING UP THE LOCAL KERMIT, A NUMBER O
F NAKS MAY HAVE.ACCUMULATED IN THE LOCAL
KERMIT'S INPUT BUFFER, SO:..5.) CLEAR
THE INPUT BUFFER AT THE BEGINNING OF A T
RANSFER..IF THE INPUT BUFFER IS NOT CLEA
RED, THE LOCAL KERMIT WILL THINK THE REM
OTE SIDE.IS HAVING TROUBLE RECEIVING THE
FIRST PACKET. IN AN EFFORT TO GET THE
PACKET.THROUGH, IT WILL BE SENT AGAIN; T
HIS REPEATS FOR EVERY NAK WAITING IN THE
INPUT.BUFFER. BY THE TIME THE FIRST AC
K IS FINALLY ENCOUNTERED IN THE BUFFER,
A.NUMBER OF DUPLICATES OF THE FIRST PACK
ET WILL HAVE BEEN SENT OUT. IF THIS.NUM
BER EXCEEDS THE NAK THRESHHOLD, THE CONN
ECTION WILL BE BROKEN. IF NOT,.HOWEVER,
THE SECOND PACKET WILL BE RETRANSMITTED
ONCE FOR EACH OF THE EXTRA.ACKS THE REM
OTE KERMIT CORRECTLY SENT FOR THE DUPLIC
ATE FIRST PACKETS. THIS.CAN CONTINUE TH
ROUGHOUT THE FILE TRANSFER, CAUSING EACH
PACKET TO BE SENT MANY.TIMES. SO, IN A
DDITION,..6.) CLEAR THE INPUT BUFFER AF
TER READING EACH PACKET..ANY COMPUTER TH
AT BUFFERS ITS INPUT SHOULD CLEAR ITS IN
PUT BUFFER BEFORE THE.TRANSFER AND AFTER
EACH PACKET THAT ARRIVES SUCCESSFULLY.
BUT SINCE NOT ALL.SYSTEMS PROVIDE A CLE
AR-BUFFER FUNCTION, WE MAY ADD ANOTHER R
ULE:..7.) DISCARD REDUNDANT ACKS..IN TH
E SITUATION JUST DESCRIBED, THE FIRST PA
CKET WOULD BE SENT OUT MULTIPLE.TIMES, O
NCE FOR EACH BUFFERED NAK. UPON RECEIPT
OF THE FIRST ACK, THE SECOND.PACKET WOU
LD GO OUT, BUT THE NEXT RESPONSE WOULD B
E ANOTHER ACK FOR THE FIRST.PACKET; BY R
ULE 7, KERMIT WOULD SIMPLY TAKE IN THE R
EDUNDANT ACK, IGNORE IT,.AND LOOK FOR TH
E NEXT ACK, UNTIL IT GOT THE DESIRED ONE
, IN VIOLATION OF THE.SPIRIT OF RULE 1..
IF WE ALLOWED OURSELVES TO VIOLATE RULE
1, WE COULD ADD A FINAL RULE,..AN ACK FO
R PACKET N ALSO ACKS ALL PREVIOUS PACKET
S, AS IS DONE IN NETWORK.PROTOCOLS LIKE
DDCMP, ALLOWING DATA PACKETS TO BE SENT
IN A CONTINUOUS STREAM..KERMIT CANNOT US
E THIS RULE FOR MANY REASONS: SEQUENCE N
UMBER WRAPAROUND,.BUFFER OVERFLOWS, LOCK
ING OUT HALF DUPLEX SYSTEMS (HOW CAN THE
Y NAK A BAD.PACKET IF THEY CAN'T GET CON
TROL OF THE LINE?). THUS IF WE VIOLATE
RULE 1,.IT MUST BE ONLY IN A VERY MINOR
WAY...EXAMPLE..HERE IS A SEQUENCE OF PAC
KETS FROM A REAL FILE TRANSFER. EACH PA
CKET STARTS.WITH CONTROL-A, SHOWN AS ^A.
..^A) SH( @-#^
SEND INIT.^A) YH( @-#%
ACK FOR SEND I
NIT.^A+!FMOON.DOC2
FILE HEADER.^A#!Y?
ACK FOR FI
LE HEADER.^AE"D NO CELESTIAL BODY HAS
REQUIRED J FIRST DATA PACKET.^A#"Y
@@
ACK FOR FIRST DATA PACKET.^AE#DAS M%%%
UCH LABOR FOR THE STUDY OF ITS# SECON
D DATA PACKET, BAD.^A##N8
NAK FOR SECOND
DATA PACKET.^AE#DAS MUCH LABOR FOR THE
STUDY OF ITS# SECOND DATA PACKET A
GAIN.^A##YA
ACK FOR SECOND DATA PACKET.^
AE$D#M#JMOTION AS THE MOON. SINCE CLAA
ETC....^A#$YB.(MANY PACKETS OMITTE
D HERE).^AD"DOUT 300 TERMS ARE SUFFICIEN
T.#M#JU LAST DATA PACKET.^A#"Y@
A
CK FOR LAST DATA.^A##ZB
EOF.^A##YA
ACK F
OR EOF.^A#$B+
EOT.^A#$YB
ACK FOR EOT..IN
THE FIRST PACKET, WE SEE FOLLOWING THE
CONTROL-A THE PACKET LENGTH ")".(41, LES
S 32, OR 9), FOLLOWED BY THE PACKET TYPE
, S (SEND-INIT), FOLLOWED BY.THE APPROPR
IATE PARAMETER DECLARATIONS: MAXIMUM PAC
KET LENGTH IS H (72-32 =.40), TIMEOUT IS
"(" (40-32 = 8), NUMBER OF PADDING CHAR
ACTERS IS 0 (SPACE =.32-32 = 0), THE PAD
DING CHARACTER IS 0, END-OF-LINE IS "-"
(45-32 = 13, THE.ASCII VALUE OF CARRIAGE
RETURN), THE CONTROL-QUOTE CHARACTER IS
"#", AND THE.REMAINING FIELDS ARE OMITT
ED, DEFAULTING TO APPROPRIATE VALUES. T
HE FINAL.CHARACTER "^" IS THE SINGLE-CHA
RACTER CHECKSUM, COMPUTED AS FOLLOWS (AL
L.NUMBERS AND COMPUTATIONS IN OCTAL, AND
"SP" REPRESENTS A SPACE):..) SP S
H ( SP @ - #..51 + 4
0 + 123 + 110 + 50 + 40 + 100 + 55 + 43
= 674..674 + (674/300) = 676..676 AND 77
= 76;..CHAR(76) = 76+40 = 136 = "^"..TH
E RECEIVER ACKS WITH ITS OWN PARAMETERS,
WHICH ARE THE SAME. THEN COMES THE.FIL
E HEADER, THE FILE, EOF, AND EOT. ONE D
ATA PACKET WAS CORRUPTED BY A BURST.OF "
%" CHARACTERS, NAK'D, AND RETRANSMITTED.
...PERFORMANCE.===========..FOR TEXT FIL
ES (DOCUMENTS OR PROGRAM SOURCE), ASSUMI
NG AN AVERAGE LINE LENGTH.OF 40 WITH LIN
ES SEPARATED BY A CARRIAGE-RETURN/LINEFE
ED PAIR, THE ONLY.CONTROL CHARACTERS NOR
MALLY FOUND IN THE TEXT FILE, WE SEE ABO
UT 5% OVERHEAD.FOR PREFIXING OF CONTROL
CHARACTERS. ASSUMING NO LINE TERMINATOR
S FOR PACKETS.(ALTHOUGH ONE OR BOTH SIDE
S MAY REQUIRE THEM), NO RETRANSMISSIONS
OR TIMEOUTS,.AND NO TIME WASTED FOR THE
LINE TO TURN AROUND BETWEEN PACKET AND R
ESPONSE,.THEN FOR AVERAGE PACKET LENGTH
P, USING A SINGLE-CHARACTER CHECKSUM, TH
E KERMIT.PROTOCOL OVERHEAD CONSISTS OF:.
. 5 CONTROL FIELD CHARACTERS IN THE DAT
A PACKET. 5 CHARACTERS IN THE ACKNOWLED
GEMENT PACKET.+ 0.05 P FOR CONTROL CHARA
CTER QUOTING..THIS GIVES 10/P + 0.05 OVE
RHEAD. E.G. IF THE PACKET LENGTH IS 40,
THERE IS 30%.OVERHEAD. IF P IS 96 (THE
MAXIMUM), THERE IS ABOUT 15%. THESE FI
GURES WILL.VARY WITH THE AVERAGE LINE LE
NGTH AND THE FREQUENCY OF OTHER CONTROL
CHARACTERS.(LIKE TABS AND FORMFEEDS) IN
THE FILE, AND WILL GO UP WITH IMMEDIATE
RETRANS-.MISSIONS, AND WAY UP WITH DELAY
ED RETRANSMISSIONS. FOR BINARY FILES, T
HE.QUOTING OVERHEAD WILL BE HIGHER. BUT
TRANSMISSION OVERHEAD CAN ALSO GO DOWN.
DRAMATICALLY IF PREFIX ENCODING IS USED
FOR REPEATED CHARACTERS, DEPENDING ON.TH
E NATURE OF THE DATA (BINARY DATA CONTAI
NING MANY ZEROES, HIGHLY INDENTED OR.COL
UMNAR DATA OR PROGRAM TEXT WILL TEND TO
BENEFIT). EACH FILE TRANSFER ALSO.GETS A
FIXED OVERHEAD FOR THE PRELIMINARY (SEN
D INIT, FILE HEADER) AND.TERMINATING (EO
F, EOT) PACKETS...IF THE MAINFRAME END O
F A CONNECTION IS HEAVILY LOADED, IT MAY
TAKE.CONSIDERABLE TIME TO DIGEST AND PR
OCESS INCOMING CHARACTERS BEFORE REPLYIN
G..ON HALF DUPLEX MAINFRAMES, THERE MAY
BE A PAUSE BETWEEN SENDING AND RECEIVING
,.EVEN IF THE LOAD IS LIGHT; THIS MIGHT
BE USED TO ADVANTAGE BY PREPARING THE.NE
XT PACKET IN ADVANCE WHILE WAITING FOR T
HE CURRENT ACK. ANOTHER PROBLEM MAY.OCC
UR ON HEAVILY LOADED MAINFRAMES - UNDESI
RABLE TIMEOUTS. TIMEOUTS ARE.INTENDED T
O DETECT LOST PACKETS. A HEAVILY LOADED
SYSTEM MAY TAKE LONGER THAN.THE TIMEOUT
INTERVAL TO SEND A PACKET. FOR THIS RE
ASON, MAINFRAME KERMITS.SHOULD TAKE THE
REQUESTED TIMEOUT INTERVAL ONLY AS A MIN
IMUM, AND SHOULD ADJUST.IT FOR EACH PACK
ET BASED ON THE CURRENT SYSTEM LOAD, UP
TO A REASONABLE.MAXIMUM. ON A NOISY LINE
, THERE IS A GREATER LIKELIHOOD OF CORRU
PTED PACKETS.AND THEREFORE OF RETRANSMIS
SION OVERHEAD. PERFORMANCE ON NOISY LIN
ES CAN BE.IMPROVED BY REDUCING THE PACKE
T LENGTH, AND THUS THE PROBABILITY THAT
ANY.PARTICULAR PACKET WILL BE CORRUPTED,
AND THE AMOUNT OF TIME REQUIRED TO.RETR
ANSMIT A CORRUPTED PACKET. A KERMIT PRO
GRAM CAN UNILATERALLY ADJUST THE.PACKET
LENGTH ACCORDING TO THE NUMBER OF RETRAN
SMISSIONS THAT ARE OCCURRING..SHORT PACK
ETS CUT DOWN ON RETRANSMISSION OVERHEAD,
LONG PACKETS CUT DOWN ON.CHARACTER OVER
HEAD...."USER INTERFACE".===============
=..KERMIT WAS DESIGNED FROM A MAINFRAME
PERSPECTIVE. LIKE MANY MAINFRAME PROGRAM
S,.KERMIT ISSUES A PROMPT, THE USER TYPE
S A COMMAND, KERMIT EXECUTES THE COMMAND
.AND ISSUES ANOTHER PROMPT, AND SO ON UN
TIL THE USER EXITS FROM THE PROGRAM..MUC
H CARE IS DEVOTED TO THE COMMAND PARSER,
EVEN ON MICROCOMPUTER VERSIONS..THE GOA
L IS TO PROVIDE ENGLISH-LIKE COMMANDS CO
MPOSED OF SEQUENCES OF KEYWORDS.OR OPERA
NDS, WITH ABBREVIATIONS POSSIBLE FOR ANY
KEYWORD IN ANY FIELD DOWN TO.THE MINIMU
M UNIQUE LENGTH, AND WITH "?" HELP AVAIL
ABLE AT ANY POINT IN A.COMMAND. NOT ALL
IMPLEMENTATIONS NEED FOLLOW THIS MODEL,
BUT MOST DO...THE BASIC COMMANDS ARE SE
ND AND RECEIVE. THESE ALLOW MOST KERMIT
S TO EXCHANGE.FILES. OPERANDS CAN BE TH
E NAME OF A SINGLE FILE, OR A FILE GROUP
DESIGNATOR.(E.G. WITH "WILDCARDS") TO T
RANSMIT MULTIPLE FILES IN A SINGLE OPERA
TION..ALTHOUGH SOME SYSTEMS MAY NOT PROV
IDE WILDCARD FILE PROCESSING, THE KERMIT
.PROTOCOL ALLOWS IT...THE CONNECT COMMAN
D PROVIDES THE MECHANISM FOR LOGGING IN
AND TYPING COMMANDS.AT THE REMOTE HOST,
WHICH IS NECESSARY IN ORDER TO START THE
KERMIT ON THAT.SIDE. THE CONNECT FACILI
TY PROVIDES CHARACTER-AT-A-TIME TRANSMIS
SION, PARITY.SELECTION, REMOTE OR LOCAL
ECHING, AND THE ABILITY TO SEND ANY CHAR
ACTER,.INCLUDING THE "ESCAPE CHARACTER"
THAT MUST BE USED TO GET BACK TO THE LOC
AL.KERMIT. HOWEVER, THERE IS NO ERROR D
ETECTION OR CORRECTION DURING CONNECT,.J
UST AS THERE NORMALLY IS NONE BETWEEN AN
ORDINARY TERMINAL AND A HOST...WHEN TWO
SYSTEMS ARE DISSIMILAR, A SET COMMAND I
S PROVIDED TO ALLOW THEM TO.ACCOMMODATE
EACH OTHER'S PECULIARITIES, FOR INSTANCE
SET PARITY ODD TO ADD.ODD PARITY TO ALL
OUTBOUND CHARACTERS, OR SET LOCAL-ECHO
TO DO LOCAL ECHOING.WHEN CONNECTED AS A
TERMINAL TO A HALF DUPLEX SYSTEM. THE S
ET COMMAND MUST.SOMETIMES BE USED TO SUP
PLY INFORMATION TO THE TARGET SYSTEM ON
HOW TO STORE.AN INCOMING FILE WITH RESPE
CT TO BLOCK SIZE, BYTE SIZE, RECORD FORM
AT, RECORD.LENGTH...MOST KERMIT IMPLEMEN
TATIONS TAKE SPECIAL CARE TO REASSURE TH
E USER DURING FILE.TRANSFER. THE NAMES
OF THE FILES BEING TRANSFERRED ARE SHOWN
, AND A DYNAMIC.DISPLAY IS MADE OF THE P
ACKET TRAFFIC, SHOWING SUCCESSFUL TRANSM
ISSION OF.PACKETS AS WELL AS TIMEOUTS AN
D RETRANSMISSIONS. MESSAGES ARE ISSUED
WHEN THE.USER CONNECTS TO THE REMOTE SYS
TEM OR ESCAPES BACK FROM IT, AND KERMIT
PROMPTS.IDENTIFY THE IMPLEMENTATION. HE
LPFUL ERROR MESSAGES ARE DISPLAYED WHEN.
NECESSARY; THESE MAY EMANATE FROM EITHER
THE LOCAL OR THE REMOTE SYSTEM..THE FIN
AL DISPOSITION OF THE TRANSFER IS CLEARL
Y STATED, COMPLETE OR FAILED...THE ACTIO
NS REQUIRED OF THE KERMIT USER DEPEND UP
ON THE DEGREE TO WHICH THE.KERMIT PROGRA
MS INVOLVED HAVE IMPLEMENTED THE SPECIFI
CATION. MINIMAL.IMPLEMENTATIONS REQUIRE
THAT THE USER CONNECT TO THE REMOTE HOS
T, START KERMIT.THERE, ISSUE A SEND (OR
RECEIVE) COMMAND, ESCAPE BACK TO THE LOC
AL MACHINE, AND.ISSUE THE COMPLEMENTARY
RECEIVE (OR SEND) COMMAND. ALL THIS MUS
T BE DONE FOR.EACH TRANSFER. MORE ADVAN
CED IMPLEMENTATIONS ALLOW THE REMOTE SID
E TO RUN AS A."SERVER" AND TO TAKE ALL I
TS INSTRUCTIONS IN SPECIAL COMMAND PACKE
TS FROM THE.LOCAL KERMIT; ALL THAT IS RE
QUIRED OF THE USER ON THE REMOTE END IS
TO CONNECT.INITIALLY IN ORDER TO START T
HE SERVER. THE SERVER WILL EVEN LOG ITS
ELF OUT.UPON COMMAND FROM THE LOCAL KERM
IT. A MINIMAL SERVER CAN PROCESS COMMAN
DS TO.SEND FILES, RECEIVE FILES, AND SHU
T ITSELF DOWN...HERE IS AN EXAMPLE OF A
SESSION IN WHICH THE USER OF AN IBM PC G
ETS FILES FROM.A DECSYSTEM-20. THE ACTI
ONS SHOWN ARE REQUIRED FOR MINIMAL KERMI
T IMPLEMEN-.TATIONS. THE PARTS THE USER
TYPES ARE UNDERLINED, COMMENTS BEGIN WI
TH "!" OR.APPEAR IN ITALICS. EVERYTHING
ELSE IS SYSTEM TYPEOUT...[KERMIT] RUN K
ERMIT ON THE PC...KERMIT V1.20..KERMIT-8
6> !THIS IS THE KERM
IT PROMPT FOR THE PC..KERMIT-86>[CONNECT
] !CONNECT TO THE DEC-20...[C
ONNECTING TO HOST. TYPE CTRL-C TO RETURN
TO PC.]..YOU ARE NOW CONNECTED TO THE D
EC-20..COLUMBIA UNIVERSITY CU20B. THE SY
STEM PRINTS ITS HERALD...[TERMINAL VT52]
!SET YOUR TERMINAL TYPE
(OPTIONAL)..[LOGIN MY-ID PASSWORD]
!LOGIN USING NORMAL LOGIN METHOD..(TH
E DEC-20 PRINTS VARIOUS MESSAGES.)..[KER
MIT] !RUN KERMIT O
N THE DEC-20...KERMIT-20>
!THIS IS KERMIT-20'S PROMPT..KERMI
T-20>[SEND *.FOR] !SEND ALL FORT
RAN FILES..[^C]
!TYPE THE ESCAPE SEQUENCE TO RETURN TO
THE PC..(BACK AT PC.)..KERMIT-86>[RECEI
VE] !TELL THE PC FILES ARE CO
MING..(THE PROGRESS OF THE TRANSFER IS S
HOWN CONTINUOUSLY ON THE SCREEN.)..TRANS
FER COMPLETE...KERMIT-86>[CONNECT]
!GET BACK TO THE DEC-20..[CONNECTI
NG TO HOST. TYPE CTRL-C TO RETURN TO PC.
]..KERMIT-20>[EXIT] !GET O
UT OF KERMIT-20...LOGOUT
!LOGOUT FROM THE DEC-20...LOGGE
D OUT JOB 55, USER MY-ID, ACCOUNT MY-ACC
OUNT, TTY 146,.AT 24-APR-83 15:18:56, U
SED 0:00:17 IN 0:21:55..[^C]
!NOW "ESCAPE" BACK TO THE
PC,.(BACK AT PC.)..KERMIT-86>EXIT
!AND EXIT FROM THE PC'S KERMI
T....THE SESSION IS SOMEWHAT SIMPLER WHE
N THE REMOTE KERMIT IS BEING RUN AS A.SE
RVER. THE USER MUST STILL CONNECT, LOG
IN, AND START KERMIT ON THE REMOTE.END,
BUT NEED NEVER AGAIN CONNECT TO ISSUE SU
BSEQUENT SEND, RECEIVE, EXIT, OR.LOGOUT
COMMANDS, EVEN THOUGH MANY TRANSACTIONS
MAY TAKE PLACE. ALL ACTIONS.CAN BE INIT
IATED FROM THE PC....ADVANCED FEATURES.=
================..AN OPTIONAL FEATURE OF
THE KERMIT PROTOCOL IS A SPECIAL PACKET
DESIGNED TO.EXPRESS THE ATTRIBUTES OF A
FILE IN A COMPACT AND GENERIC MANNER. T
HE RECEIVER.MAY EITHER ATTEMPT TO USE TH
E ATTRIBUTES TO THE INCOMING FILE, OR AR
CHIVE THEM.FOR LATER USE. ATTRIBUTES IN
CLUDE NOT ONLY FILE CHARACTERISTICS BUT
ALSO THE.INTENDED DISPOSITION - STORE, P
RINT, SUBMIT FOR BATCH PROCESSING, SEND
AS MAIL,.ETC. OTHER OPTIONAL FEATURES I
NCLUDE MECHANISMS FOR GRACEFULLY INTERRU
PTING,.DELAYING, OR SUSPENDING OPERATION
S IN PROGRESS; ALTERNATE FORMS OF PACKET
DATA.ENCODING; FILENAME CONVERSION, LOC
AL FILE MANAGEMENT, RAW DATA TRANSMISSIO
N AND.CAPTURE; COMMAND MACRO DEFINITION,
ETC. ALTHOUGH KERMIT WAS NEVER INTENDED
TO.FULFILL THE ROLE OF A GENERAL PURPOS
E NETWORK SERVER, ITS DESIGN HAS MADE IT
.SIMPLE TO ADD NEW FUNCTIONS. A KERMIT
SERVER HAS THE ABILITY TO ACCEPT.COMMAND
S IN PACKETS FROM A REMOTE KERMIT...THE
BASIC COMMANDS ARE FOR SENDING OR FETCHI
NG FILES AND FOR SHUTTING DOWN THE.SERVE
R. OTHER COMMANDS MAY REQUIRE DISPLAY O
F TEXT AT THE USER'S TERMINAL,.WHICH IS
CONTROLLED BY THE LOCAL KERMIT. FOR EXA
MPLE, A DIRECTORY LISTING.COULD BE REQUE
STED; THE RESULTING TEXT IS SENT BACK TO
THE LOCAL KERMIT EXACTLY.AS IF A FILE W
ERE BEING TRANSFERRED, EXCEPT THE DESTIN
ATION IS THE USER'S.SCREEN, RATHER THAN
A DISK FILE. (OR IT COULD BE DISK FILE
TOO.) WITH THIS.ABILITY IN PLACE, IT IS
POSSIBLE TO IMPLEMENT ALL SORTS OF COMM
ANDS, FOR.INSTANCE TO DELETE A FILE, SHO
W WHO'S LOGGED IN, INQUIRE ABOUT DISK SP
ACE,.VERIFY ACCESS TO A DIRECTORY, SUBMI
T BATCH JOBS, SEND MESSAGES, AND SO FORT
H...THE ABILITY OF THE KERMIT SERVER TO
PERFORM HOST FUNCTIONS CAN BE ADDED VERY
.SIMPLY UNDER CERTAIN OPERATING SYSTEMS.
FOR INSTANCE, UNDER UNIX, KERMIT CAN."
FORK" A SHELL WITH COMMANDS TO PERFORM A
NY FUNCTION POSSIBLE UNDER UNIX,.REDIREC
TING THE STANDARD OUTPUT THROUGH A PROCE
SS (KERMIT ITSELF) THAT.ENCAPSULATES IT
INTO KERMIT PACKETS AND SENDS IT ALONG.
A SERVER WITH THESE.CAPABILITIES COULD P
ROVIDE CONVENIENT ACCESS TO A TIMESHARIN
G SYSTEM BY USERS.AT PERSONAL WORKSTATIO
NS, WITHOUT REQUIRING THE USERS TO BE DI
RECTLY INVOLVED.WITH THE HOST. IF, FOR
INSTANCE, WORKSTATIONS HAD DEDICATED CON
NECTIONS TO A.HOST, AND THE HOST HAD DED
ICATED KERMIT SERVERS FOR EACH SUCH LINE
, USERS COULD.GET ACCESS TO AND MANAGE T
HEIR HOST FILES COMPLETELY BY COMMANDS T
YPED AT THE.WORKSTATION. TAKING THIS ID
EA ONE STEP FURTHER, THE WORKSTATION SYS
TEM.SOFTWARE COULD BE MODIFIED TO MAKE T
HE WHOLE PROCESS TRANSPARENT BY INCOR-.P
ORATING A KERMIT-LIKE PROTOCOL IN ITS FI
LE ACCESS LOGIC - FETCHING AND UP-.DATIN
G HOST FILES AS NECESSARY BEHIND THE USE
R'S BACK. SINCE THE DEMANDS.PLACED ON A
HOST BY KERMIT ARE RELATIVELY MODEST, M
ANY MORE SIMULTANEOUS USERS.COULD PROBAB
LY BE SERVICED IN THIS WAY. THIS APPROA
CH COULD BE A RELATIVELY.PAINLESS ENTREE
INTO THE DISTRIBUTED, NETWORKED ENVIRON
MENT OF TOMORROW. WHEN.LOCAL AREA NETWO
RK PROTOCOLS BECOME MATURE AND THE HARDW
ARE ECONOMICAL AND.WIDESPREAD, KERMIT CA
N BE REPLACED BY "THE REAL THING". BUT
FOR THE ORDINARY.COMPUTER USER FOR WHOM
DEDICATED CONNECTIONS ARE IMPRACTICAL, "
DO-IT-YOURSELF".KERMIT, OR SOME FACILITY
LIKE IT, WILL BE A VALUABLE TOOL FOR YE
ARS TO COME....CONCLUSION.==========..TH
E NEED FOR A CHEAP, CONVENIENT FILE TRAN
SFER CAPABILITY AMONG DIVERSE SYSTEMS.IS
PRESSING, AND THERE ARE CERTAINLY MANY
EFFORTS SIMILAR TO OURS UNDER WAY AT.MAN
Y PLACES. WE HOPE THAT THIS ARTICLE MAY
CONTRIBUTE TO THOSE EFFORTS; WE.DON'T C
LAIM TO HAVE THE LAST WORD ON ANY OF THE
ISSUES RAISED HERE, AND EXPECT.THAT THI
S ARTICLE MAY FLUSH SOME OTHER APPROACHE
S OUT OF THE WOODWORK. WE HAVE.BILLED K
ERMIT AS A "SIMPLE" PROTOCOL; ANYONE WHO
HAS READ THIS FAR WILL BEGIN.TO APPRECI
ATE WHAT MUST GO INTO THE MORE COMPLICAT
ED PROTOCOLS USED IN REAL.NETWORKS, OR W
HEN "INTEGRATION" OF MICRO AND MAINFRAME
IS A MAJOR GOAL - DEMAND.PAGING OF REMO
TE FILES, REMOTE DATABASE QUERIES, DISTR
IBUTED EDITING AND.COMPUTATION. MEANWHIL
E, THE KERMIT PROTOCOL HAS BEEN PROVEN S
UCCESSFUL, AND.CONTINUES TO GROW IN POPU
LARITY. AS OF THIS WRITING, IMPLEMENTAT
IONS EXIST FOR.MORE THAN 50 COMPUTER SYS
TEMS. SOME OF THE MAJOR ONES INCLUDE:..
MACHINE OPERATING SYSTEM
LANGUAGE..DECSYSTEM-10 TOPS-
10 MACRO-10.DECSYSTEM-20
TOPS-20 MACRO-20.IBM
370 SERIES VM/CMS
IBM ASSEMBLER.VAX-11 VMS
BLISS-32.VAX,SUN,PDP-11
,ETC. UNIX C.PDP-11
RT-11,RSX,RSTS MACRO-
11.8080,8085,OR Z80 CP/M
8080 ASM.8086,8088 PC
DOS,MS DOS@ IBM PC ASSEMBLER.APPLE
II 6502 APPLE DOS DE
C-10/20 CROSS..SOME OF THESE HAVE BEEN C
ONTRIBUTED OR ENHANCED BY THE INSTITUTIO
NS LISTED IN.THE ACKNOWLEDGEMENTS, BELOW
. NO SINGLE IMPLEMENTATION NECESSARILY
INCLUDES ALL.THE FEATURES MENTIONED IN T
HIS ARTICLE, BUT ALL ARE ABLE TO COMMUNI
CATE AT.LEAST AT BASE LEVEL. ADDITIONAL
IMPLEMENTATIONS ARE IN PREPARATION, AND
.PRESENT ONES ARE BEING ENHANCED...COLUM
BIA UNIVERSITY IS WILLING TO PROVIDE ALL
KERMIT PROGRAMS, SOURCES,.MANUALS, AND
OTHER DOCUMENTATION TO COMPUTING CENTERS
, ACADEMIC OR CORPORATE,.IN RETURN FOR A
MODEST FEE TO COVER COSTS FOR MEDIA, PR
INTING, POSTAGE, LABOR,.AND COMPUTING RE
SOURCES. ONLY MAGNETIC TAPE AND LISTING
S CAN BE SHIPPED. WE.CANNOT PRODUCE FLO
PPY DISKS; INSTRUCTIONS ARE INCLUDED FOR
BOOTSTRAPPING THE.MICROCOMPUTER IMPLEME
NTATIONS FROM THE MAINFRAME COMPUTERS.
DETAILS WILL BE.PROVIDED ON REQUEST; WRI
TE TO:..KERMIT DISTRIBUTION.COLUMBIA UNI
VERSITY CENTER FOR COMPUTING ACTIVITIES.
7TH FLOOR, WATSON LABORATORY.612 WEST 11
5TH STREET.NEW YORK, NY 10025..THE PROT
OCOL SPECIFICATION SUPPLEMENTED BY EXAMP
LES OF EXISTING KERMIT.IMPLEMENTATIONS A
LLOWS NEW IMPLEMENTATIONS TO BE CREATED
WITH RELATIVE EASE..IN THE PAST, KERMIT
IMPLEMENTORS HAVE SHARED THEIR WORK WITH
OTHER KERMIT USERS.BY CONTRIBUTING IT T
O THE COLUMBIA KERMIT LIBRARY. WE HOPE
THAT THIS PRACTICE.WILL CONTINUE UNTIL K
ERMIT HAS SPREAD THROUGHOUT THE KNOWN WO
RLD....ACKNOWLEDGEMENTS.================
..IN DESIGNING THE INITIAL KERMIT PROTOC
OL, WE STUDIED SEVERAL MODELS, PRIMARILY
.THE ANSI RECOMMENDATION. OTHERS INCLUDE
THE STANFORD UNIVERSITY DIALNET.PROJECT
, THE UNIVERSITY OF UTAH "SMALL FTP" PRO
JECT, AND THE STANFORD.UNIVERSITY MEDICA
L CENTER TTYFTP PROJECT. AND WE EXAMINED
SOME REAL NETWORKS,.LIKE ARPANET AND DE
CNET...ACKNOWLEDGEMENTS ALSO TO THE MANY
SITES THAT HAVE CONTRIBUTED NEW KERMIT.
IMPLEMENTATIONS OR ENHANCED OLD ONES: ST
EVENS INSTITUTE OF TECHNOLOGY, DIGITAL.E
QUIPMENT CORPORATION, THE NATIONAL INSTI
TUTES OF HEALTH, CORNELL UNIVERSITY,.THE
UNIVERSITY OF TORONTO, THE UNIVERSITY O
F TENNESSEE, THE UNIVERSITY OF.TOLEDO, C
ERRITOS COLLEGE, AND MANY OTHERS. THANK
S TO DR. HOWARD ESKIN FOR.HELP WITH THIS
ARTICLE....THE ASCII ALPHABET.=========
=========..DEC OCT CHARACTER DEC OCT..0
00 000 NUL (^@) 064 100 @.001 001 SOH
(^A) 065 101 A.002 002 STX (^B) 066
102 B.003 003 ETX (^C) 067 103 C.004 0
04 EOT (^D) 068 104 D.005 005 ENQ (^E)
069 105 E.006 006 ACK (^F) 070 106
F.007 007 BEL (^G) 071 107 G.008 010 B
S (^H) 072 110 H.009 011 HT (^I) 0
73 111 I.010 012 LF (^J) 074 112 J.01
1 013 VT (^K) 075 113 K.012 014 FF (
^L) 076 114 L.013 015 CR (^M) 077 1
15 M.014 016 SO (^N) 078 116 N.015 01
7 SI (^O) 079 117 O.016 020 DLE (^P)
080 120 P.017 021 DC1 (^Q) 081 121 Q
.018 022 DC2 (^R) 082 122 R.019 023 DC
3 (^S) 083 123 S.020 024 DC4 (^T) 08
4 124 T.021 025 NAK (^U) 085 125 U.022
026 SYN (^V) 086 126 V.023 027 ETB (^
W) 087 127 W.024 030 CAN (^X) 088 13
0 X.025 031 EM (^Y) 089 131 Y.026 032
SUB (^Z) 090 132 Z.027 033 ESC (^[)
091 133 [.028 034 FS (^\) 092 134 \.
029 035 GS (^]) 093 135 ].030 036 RS
(^^) 094 136 ^.031 037 US (^_) 095
137 _.032 040 (SP) 096 140 .033
041 ! 097 141 A.034 042 "
098 142 B.035 043 # 099 143
C.036 044 $ 100 144 D.037 045
% 101 145 E.038 046 &
102 146 F.039 047 ' 103 147 G.0
40 050 ( 104 150 H.041 051 )
105 151 I.042 052 * 106
152 J.043 053 + 107 153 K.044 0
54 , 108 154 L.045 055 -
109 155 M.046 056 . 110 156
N.047 057 / 111 157 O.048 060 0
112 160 P.049 061 1 1
13 161 Q.050 062 2 114 162 R.05
1 063 3 115 163 S.052 064 4
116 164 T.053 065 5 117 1
65 U.054 066 6 118 166 V.055 06
7 7 119 167 W.056 070 8
120 170 X.057 071 9 121 171 Y
.058 072 : 122 172 Z.059 073 ;
123 173 ;.060 074 < 12
4 174 ].061 075 = 125 175 =.062
076 > 126 176 >.063 077 ?
127 177 DEL...* * * END OF FILE * *
*..GREETINGS TO ALL KERMIT-USERS ......
HAI..R; T=0.73/2.59 14:47:01.
> CLICK IMAGE PREVIEW FOR FULL MODAL