NYBBLE.ASM
FILE INFORMATION
FILENAME(S): NYBBLE.ASM
FILE TYPE(S): PRG
FILE SIZE: 1.4K
FIRST SEEN: 2025-10-19 22:48:34
APPEARS ON: 3 disk(s)
FILE HASH
e8531e3bc82851584bb6e58c7d1435e58eb3da476834bc1059e0436f34664e09
FOUND ON DISKS (3 DISKS)
| DISK TITLE | FILENAME | FILE TYPE | COLLECTION | TRACK | SECTOR | ACTIONS |
|---|---|---|---|---|---|---|
| MM UTILITY | NYBBLE.ASM | PRG | Radd Maxx | 2 | 15 | DOWNLOAD FILE |
| PPM VOL II | NYBBLE.ASM | PRG | High Voltage Complete C64 Collection | 22 | 8 | DOWNLOAD FILE |
| 1541 DEVELOPMENT | NYBBLE.ASM | PRG | Sailor, Ganheden | 34 | 9 | DOWNLOAD FILE |
FILE CONTENT & ANALYSIS
> DETECTED: COMMODORE BASIC PROGRAM (LOAD ADDRESS $0801)
00000000: 01 08 41 08 24 04 AC B2 24 34 33 30 30 20 20 20 |..A.$...$4300 | 00000010: 20 20 20 20 20 3B 52 4F 55 54 49 4E 45 20 A4 20 | ;ROUTINE . | 00000020: 4E 59 42 42 4C 45 20 43 4F 55 4E 54 20 28 42 59 |NYBBLE COUNT (BY| 00000030: 54 45 20 43 4F 55 4E 54 29 20 41 20 54 52 41 43 |TE COUNT) A TRAC| 00000040: 4B 00 49 08 2E 04 53 45 49 00 74 08 38 04 4C 44 |K.I...SEI.t.8.LD| 00000050: 59 20 23 24 30 30 20 20 20 20 20 20 20 3B 46 49 |Y #$00 ;FI| 00000060: 4C 4C 20 57 B0 4B 20 53 50 41 43 45 20 57 49 54 |LL W.K SPACE WIT| 00000070: 48 20 30 30 00 81 08 42 04 4C 44 41 20 23 24 30 |H 00...B.LDA #$0| 00000080: 30 00 91 08 4C 04 43 4C 45 41 52 49 54 20 B2 20 |0...L.CLEARIT . | 00000090: AC 00 BC 08 56 04 53 54 41 20 24 30 34 30 30 2C |....V.STA $0400,| 000000A0: 59 20 20 20 20 3B 53 A4 52 45 20 30 30 20 41 54 |Y ;S.RE 00 AT| 000000B0: 20 24 30 34 30 30 AB 24 30 34 46 46 00 C4 08 60 | $0400.$04FF...`| 000000C0: 04 49 4E 59 00 D4 08 6A 04 42 4E 45 20 43 4C 45 |.INY...j.BNE CLE| 000000D0: 41 52 49 54 00 F9 08 74 04 4A 53 52 20 24 46 45 |ARIT...t.JSR $FE| 000000E0: 30 30 20 20 20 20 20 20 3B 53 45 54 20 50 43 52 |00 ;SET PCR| 000000F0: 20 A4 20 87 20 4D 4F 44 45 00 07 09 7E 04 4C 44 | . . MODE...~.LD| 00000100: 41 20 24 31 43 30 43 00 13 09 88 04 B0 41 20 23 |A $1C0C......A #| 00000110: 24 30 45 00 21 09 92 04 53 54 41 20 24 31 43 30 |$0E.!...STA $1C0| 00000120: 43 00 32 09 9C 04 46 49 4E 44 53 59 4E 43 20 B2 |C.2...FINDSYNC .| 00000130: 20 AC 00 5A 09 A6 04 4C 44 58 20 23 24 30 30 20 | ..Z...LDX #$00 | 00000140: 20 20 20 20 20 20 3B 53 45 54 20 55 50 20 54 49 | ;SET UP TI| 00000150: 4D 45 52 20 81 20 53 59 4E 43 00 67 09 B0 04 4C |MER . SYNC.g...L| 00000160: 44 59 20 23 24 30 30 00 77 09 BA 04 54 49 4D 45 |DY #$00.w...TIME| 00000170: 4F 55 54 20 B2 20 AC 00 7F 09 C4 04 44 45 59 00 |OUT . ......DEY.| 00000180: 8D 09 CE 04 42 4E 45 20 92 53 59 4E 43 00 95 09 |....BNE .SYNC...| 00000190: D8 04 44 45 58 00 A3 09 E2 04 42 4E 45 20 92 53 |..DEX.....BNE .S| 000001A0: 59 4E 43 00 DA 09 EC 04 4C 44 41 20 23 24 30 33 |YNC.....LDA #$03| 000001B0: 20 20 20 20 20 20 20 3B 30 33 B2 4E 4F 20 53 59 | ;03.NO SY| 000001C0: 4E 43 20 20 20 8B 20 4E 4F 20 53 59 4E 43 20 91 |NC . NO SYNC .| 000001D0: 20 54 52 41 43 4B 20 A7 20 80 00 FA 09 F6 04 53 | TRACK . ......S| 000001E0: 54 41 20 24 30 30 20 20 20 20 20 20 20 20 3B 94 |TA $00 ;.| 000001F0: 20 45 52 52 B0 20 43 4F 44 45 00 08 0A 00 05 4A | ERR. CODE.....J| 00000200: 4D 50 20 24 46 39 36 39 00 29 0A 0A 05 92 53 59 |MP $F969.)....SY| 00000210: 4E 43 20 B2 20 AC 20 20 20 20 20 20 3B 43 48 45 |NC . . ;CHE| 00000220: 43 4B 20 81 20 53 59 4E 43 00 37 0A 14 05 42 49 |CK . SYNC.7...BI| 00000230: 54 20 24 31 43 30 30 00 47 0A 1E 05 42 4D 49 20 |T $1C00.G...BMI | 00000240: 54 49 4D 45 4F 55 54 00 6B 0A 28 05 4C 44 41 20 |TIMEOUT.k.(.LDA | 00000250: 24 31 43 30 31 20 20 20 20 20 20 3B 53 4B 49 50 |$1C01 ;SKIP| 00000260: 20 46 49 52 53 54 20 42 59 54 45 00 73 0A 32 05 | FIRST BYTE.s.2.| 00000270: 43 4C 56 00 B3 0A 3C 05 4C 44 41 20 23 24 32 42 |CLV...<.LDA #$2B| 00000280: 20 20 20 20 20 20 20 3B 53 45 54 20 43 4F 55 4E | ;SET COUN| 00000290: 54 45 52 20 A4 20 4E 55 4D 42 45 52 20 4F 46 20 |TER . NUMBER OF | 000002A0: 53 59 4E 43 53 AA 31 20 91 20 54 48 45 20 54 52 |SYNCS.1 . THE TR| 000002B0: 41 43 4B 00 EF 0A 46 05 53 54 41 20 24 31 34 20 |ACK...F.STA $14 | 000002C0: 20 20 20 20 20 20 20 3B 9A 45 52 20 49 53 20 53 | ;.ER IS S| 000002D0: A4 52 45 44 20 41 54 20 41 4E 20 55 4E 55 53 45 |.RED AT AN UNUSE| 000002E0: 44 20 4C 4F 43 41 54 49 91 20 24 30 30 31 34 00 |D LOCATI. $0014.| 000002F0: FC 0A 50 05 4C 44 58 20 23 24 30 30 00 09 0B 5A |..P.LDX #$00...Z| 00000300: 05 4C 44 59 20 23 24 30 30 00 1A 0B 64 05 53 59 |.LDY #$00...d.SY| 00000310: 4E 43 31 42 45 47 20 B2 20 AC 00 47 0B 6E 05 42 |NC1BEG . ..G.n.B| 00000320: 49 54 20 24 31 43 30 30 20 20 20 20 20 20 3B 46 |IT $1C00 ;F| 00000330: 49 4E 44 20 53 59 4E 43 20 4D 41 52 4B 20 42 45 |IND SYNC MARK BE| 00000340: 47 49 4E 4E 49 4E 47 00 58 0B 78 05 42 4D 49 20 |GINNING.X.x.BMI | 00000350: 53 59 4E 43 31 42 45 47 00 7C 0B 82 05 44 45 43 |SYNC1BEG.|...DEC| 00000360: 43 4F 55 4E 54 20 B2 20 AC 20 20 20 3B 44 45 43 |COUNT . . ;DEC| 00000370: 8F 45 4E 54 20 43 4F 55 4E 54 45 52 00 88 0B 8C |.ENT COUNTER....| 00000380: 05 44 45 43 20 24 31 34 00 94 0B 96 05 42 45 51 |.DEC $14.....BEQ| 00000390: 20 80 49 54 00 A3 0B A0 05 53 59 4E 43 31 80 20 | .IT.....SYNC1. | 000003A0: B2 20 AC 00 CA 0B AA 05 42 49 54 20 24 31 43 30 |. ......BIT $1C0| 000003B0: 30 20 20 20 20 20 20 3B 92 20 81 20 80 20 4F 46 |0 ;. . . OF| 000003C0: 20 53 59 4E 43 20 4D 41 52 4B 00 D9 0B B4 05 42 | SYNC MARK.....B| 000003D0: 50 4C 20 53 59 4E 43 31 80 00 FB 0B BE 05 A1 42 |PL SYNC1.......B| 000003E0: 59 54 45 20 B2 20 AC 20 20 20 20 3B 53 54 41 52 |YTE . . ;STAR| 000003F0: 54 20 43 4F 55 4E 54 20 4E 4F 57 00 2A 0C C8 05 |T COUNT NOW.*...| 00000400: 4C 44 41 20 24 31 43 30 30 20 20 20 20 20 20 3B |LDA $1C00 ;| 00000410: 43 48 45 43 4B 20 81 20 53 54 41 52 54 20 4F 46 |CHECK . START OF| 00000420: 20 53 59 4E 43 20 42 59 54 45 00 3B 0C D2 05 42 | SYNC BYTE.;...B| 00000430: 50 4C 20 44 45 43 43 4F 55 4E 54 00 68 0C DC 05 |PL DECCOUNT.h...| 00000440: 42 56 43 20 A1 42 59 54 45 20 20 20 20 3B A8 45 |BVC .BYTE ;.E| 00000450: 20 43 48 41 4E 47 45 20 49 4E 20 A1 42 59 54 45 | CHANGE IN .BYTE| 00000460: 20 52 4F 55 54 49 4E 45 00 70 0C E6 05 43 4C 56 | ROUTINE.p...CLV| 00000470: 00 A4 0C F0 05 49 4E 58 20 20 20 20 20 20 20 20 |.....INX | 00000480: 20 20 20 20 3B 49 4E 43 8F 45 4E 54 20 42 59 54 | ;INC.ENT BYT| 00000490: 45 20 43 4F 55 4E 54 45 52 20 2D 20 4C 4F 57 20 |E COUNTER - LOW | 000004A0: 42 59 54 45 00 C6 0C FA 05 42 4E 45 20 A1 42 59 |BYTE.....BNE .BY| 000004B0: 54 45 20 20 20 20 3B 43 4F 55 4E 54 20 32 35 36 |TE ;COUNT 256| 000004C0: 20 42 59 54 45 53 00 FB 0C 04 06 49 4E 59 20 20 | BYTES.....INY | 000004D0: 20 20 20 20 20 20 20 20 20 20 3B 49 4E 43 8F 45 | ;INC.E| 000004E0: 4E 54 20 42 59 54 45 20 43 4F 55 4E 54 45 52 20 |NT BYTE COUNTER | 000004F0: 2D 20 48 49 47 48 20 42 59 54 45 00 09 0D 0E 06 |- HIGH BYTE.....| 00000500: 42 4E 45 20 A1 42 59 54 45 00 2B 0D 18 06 80 49 |BNE .BYTE.+....I| 00000510: 54 20 B2 20 AC 20 20 20 20 20 20 20 20 3B 46 49 |T . . ;FI| 00000520: 4E 49 53 48 20 55 50 20 AF 20 80 00 38 0D 22 06 |NISH UP . ..8.".| 00000530: 4C 44 41 20 23 24 30 31 00 46 0D 2C 06 53 54 41 |LDA #$01.F.,.STA| 00000540: 20 24 30 30 30 30 00 54 0D 36 06 53 54 58 20 24 | $0000.T.6.STX $| 00000550: 30 34 30 30 00 62 0D 40 06 53 54 59 20 24 30 34 |0400.b.@.STY $04| 00000560: 30 31 00 70 0D 4A 06 4A 4D 50 20 24 46 39 36 39 |01.p.J.JMP $F969| 00000570: 00 00 00 |... |
..A.$...$4300 ;ROUTINE . NYBBLE C
OUNT (BYTE COUNT) A TRACK.I...SEI.T.8.LD
Y #$00 ;FILL W.K SPACE WITH 00...B
.LDA #$00...L.CLEARIT . ....V.STA $0400,
Y ;S.RE 00 AT $0400.$04FF.D.`.INY.T.J
.BNE CLEARIT...T.JSR $FE00 ;SET PCR
. . MODE...~.LDA $1C0C......A #$0E.!...
STA $1C0C.2...FINDSYNC . ..Z...LDX #$00
;SET UP TIMER . SYNC.G...LDY #$00.
W...TIMEOUT . ...D.DEY...N.BNE .SYNC...
X.DEX.....BNE .SYNC.Z...LDA #$03 ;
03.NO SYNC . NO SYNC . TRACK . ......S
TA $00 ;. ERR. CODE.....JMP $F969
.)....SYNC . . ;CHECK . SYNC.7...BI
T $1C00.G...BMI TIMEOUT.K.(.LDA $1C01
;SKIP FIRST BYTE.S.2.CLV...<.LDA #$2B
;SET COUNTER . NUMBER OF SYNCS.1
. THE TRACK...F.STA $14 ;.ER IS S
.RED AT AN UNUSED LOCATI. $0014...P.LDX
#$00...Z.LDY #$00...D.SYNC1BEG . ..G.N.B
IT $1C00 ;FIND SYNC MARK BEGINNING.
X.X.BMI SYNC1BEG.|...DECCOUNT . . ;DEC
.ENT COUNTER.....DEC $14.....BEQ .IT...
.SYNC1. . ..J...BIT $1C00 ;. . . OF
SYNC MARK.Y...BPL SYNC1.......BYTE . .
;START COUNT NOW.*.H.LDA $1C00 ;
CHECK . START OF SYNC BYTE.;.R.BPL DECCO
UNT.H...BVC .BYTE ;.E CHANGE IN .BYTE
ROUTINE.P...CLV.....INX ;INC
.ENT BYTE COUNTER - LOW BYTE.F...BNE .BY
TE ;COUNT 256 BYTES.....INY
;INC.ENT BYTE COUNTER - HIGH BYTE.....
BNE .BYTE.+....IT . . ;FINISH UP
. ..8.".LDA #$01.F.,.STA $0000.T.6.STX $
0400.B.@.STY $0401.P.J.JMP $F969...
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