HALF TRACK.ASM
FILE INFORMATION
FILENAME(S): HALF TRACK.ASM
FILE TYPE(S): PRG
FILE SIZE: 1.3K
FIRST SEEN: 2025-10-19 22:48:34
APPEARS ON: 3 disk(s)
FILE HASH
993dc73e7003d29837f0d3b945cee9d0052245159f92e2827f07e3ddfb7e0541
FOUND ON DISKS (3 DISKS)
| DISK TITLE | FILENAME | FILE TYPE | COLLECTION | TRACK | SECTOR | ACTIONS |
|---|---|---|---|---|---|---|
| MM UTILITY | HALF TRACK.ASM | PRG | Radd Maxx | 2 | 2 | DOWNLOAD FILE |
| PPM VOL II | HALF TRACK.ASM | PRG | High Voltage Complete C64 Collection | 22 | 1 | DOWNLOAD FILE |
| 1541 DEVELOPMENT | HALF TRACK.ASM | PRG | Sailor, Ganheden | 34 | 1 | DOWNLOAD FILE |
FILE CONTENT & ANALYSIS
> DETECTED: COMMODORE BASIC PROGRAM (LOAD ADDRESS $0801)
00000000: 01 08 30 08 1A 04 AC B2 24 34 33 30 30 20 20 20 |..0.....$4300 | 00000010: 20 20 20 20 20 3B 52 4F 55 54 49 4E 45 20 A4 20 | ;ROUTINE . | 00000020: 87 20 48 41 4C 46 20 54 52 41 43 4B 53 20 56 33 |. HALF TRACKS V3| 00000030: 00 38 08 24 04 53 45 49 00 63 08 2E 04 4C 44 59 |.8.$.SEI.c...LDY| 00000040: 20 23 24 30 30 20 20 20 20 20 20 20 3B 46 49 4C | #$00 ;FIL| 00000050: 4C 20 57 B0 4B 20 53 50 41 43 45 20 57 49 54 48 |L W.K SPACE WITH| 00000060: 20 30 30 00 70 08 38 04 4C 44 41 20 23 24 30 30 | 00.p.8.LDA #$00| 00000070: 00 80 08 42 04 43 4C 45 41 52 49 54 20 B2 20 AC |...B.CLEARIT . .| 00000080: 00 AB 08 4C 04 53 54 41 20 24 30 34 30 30 2C 59 |...L.STA $0400,Y| 00000090: 20 20 20 20 3B 53 A4 52 45 20 30 30 20 41 54 20 | ;S.RE 00 AT | 000000A0: 24 30 34 30 30 AB 24 30 34 46 46 00 B3 08 56 04 |$0400.$04FF...V.| 000000B0: 49 4E 59 00 C3 08 60 04 42 4E 45 20 43 4C 45 41 |INY...`.BNE CLEA| 000000C0: 52 49 54 00 E8 08 6A 04 4A 53 52 20 24 46 45 30 |RIT...j.JSR $FE0| 000000D0: 30 20 20 20 20 20 20 3B 53 45 54 20 50 43 52 20 |0 ;SET PCR | 000000E0: A4 20 87 20 4D 4F 44 45 00 F6 08 74 04 4C 44 41 |. . MODE...t.LDA| 000000F0: 20 24 31 43 30 43 00 02 09 7E 04 B0 41 20 23 24 | $1C0C...~..A #$| 00000100: 30 45 00 10 09 88 04 53 54 41 20 24 31 43 30 43 |0E.....STA $1C0C| 00000110: 00 3A 09 92 04 4C 44 58 20 24 31 43 30 30 20 20 |.:...LDX $1C00 | 00000120: 20 20 20 20 3B A9 20 48 45 41 44 20 49 4E 20 48 | ;. HEAD IN H| 00000130: 41 4C 46 20 54 52 41 43 4B 53 00 71 09 9C 04 49 |ALF TRACKS.q...I| 00000140: 4E 58 20 20 20 20 20 20 20 20 20 20 20 20 3B 43 |NX ;C| 00000150: 48 41 4E 47 45 20 A4 20 44 45 58 20 A4 20 4D 4F |HANGE . DEX . MO| 00000160: 56 45 20 48 45 41 44 20 4F 54 48 45 52 20 57 41 |VE HEAD OTHER WA| 00000170: 59 00 79 09 A6 04 54 58 41 00 9C 09 B0 04 AF 20 |Y.y...TXA...... | 00000180: 23 24 30 33 20 20 20 20 20 20 20 3B 43 59 43 4C |#$03 ;CYCL| 00000190: 45 20 42 49 54 53 20 30 20 26 20 31 00 AA 09 BA |E BITS 0 & 1....| 000001A0: 04 53 54 41 20 24 30 30 31 34 00 B8 09 C4 04 4C |.STA $0014.....L| 000001B0: 44 41 20 24 31 43 30 30 00 C3 09 CE 04 AF 20 23 |DA $1C00...... #| 000001C0: 24 46 43 00 D0 09 D8 04 B0 41 20 24 30 30 31 34 |$FC......A $0014| 000001D0: 00 F5 09 E2 04 53 54 41 20 24 31 43 30 30 20 20 |.....STA $1C00 | 000001E0: 20 20 20 20 3B A9 20 48 45 41 44 20 31 AD 32 20 | ;. HEAD 1.2 | 000001F0: 54 52 41 43 4B 00 1B 0A EC 04 4C 44 58 20 23 24 |TRACK.....LDX #$| 00000200: 41 41 20 20 20 20 20 20 20 3B 92 20 81 20 48 45 |AA ;. . HE| 00000210: 41 44 20 A4 20 53 45 54 54 4C 45 00 2A 0A F6 04 |AD . SETTLE.*...| 00000220: 44 45 4C 41 59 31 20 B2 20 AC 00 37 0A 00 05 4C |DELAY1 . ..7...L| 00000230: 44 59 20 23 24 30 30 00 46 0A 0A 05 44 45 4C 41 |DY #$00.F...DELA| 00000240: 59 32 20 B2 20 AC 00 4E 0A 14 05 44 45 59 00 5D |Y2 . ..N...DEY.]| 00000250: 0A 1E 05 42 4E 45 20 44 45 4C 41 59 32 00 65 0A |...BNE DELAY2.e.| 00000260: 28 05 44 45 58 00 93 0A 32 05 42 4E 45 20 44 45 |(.DEX...2.BNE DE| 00000270: 4C 41 59 31 20 20 20 20 3B 48 45 41 44 20 53 45 |LAY1 ;HEAD SE| 00000280: 54 54 4C 45 44 20 41 54 20 48 41 4C 46 20 54 52 |TTLED AT HALF TR| 00000290: 41 43 4B 00 BA 0A 3C 05 4C 44 58 20 23 24 30 30 |ACK...<.LDX #$00| 000002A0: 20 20 20 20 20 20 3B 53 45 54 20 55 50 20 54 49 | ;SET UP TI| 000002B0: 4D 45 52 20 81 20 53 59 4E 43 00 C7 0A 46 05 4C |MER . SYNC...F.L| 000002C0: 44 59 20 23 24 30 30 00 D7 0A 50 05 54 49 4D 45 |DY #$00...P.TIME| 000002D0: 4F 55 54 20 B2 20 AC 00 DF 0A 5A 05 44 45 59 00 |OUT . ....Z.DEY.| 000002E0: ED 0A 64 05 42 4E 45 20 92 53 59 4E 43 00 F5 0A |..d.BNE .SYNC...| 000002F0: 6E 05 44 45 58 00 03 0B 78 05 42 4E 45 20 92 53 |n.DEX...x.BNE .S| 00000300: 59 4E 43 00 31 0B 82 05 4C 44 41 20 23 24 30 33 |YNC.1...LDA #$03| 00000310: 20 20 20 20 20 20 3B 30 33 B2 4E 4F 20 53 59 4E | ;03.NO SYN| 00000320: 43 20 20 20 8B 20 4E 4F 20 53 59 4E 43 20 A7 20 |C . NO SYNC . | 00000330: 80 00 3D 0B 8C 05 42 4E 45 20 80 49 54 00 5E 0B |..=...BNE .IT.^.| 00000340: 96 05 92 53 59 4E 43 20 B2 20 AC 20 20 20 20 20 |...SYNC . . | 00000350: 20 3B 43 48 45 43 4B 20 81 20 53 59 4E 43 00 6C | ;CHECK . SYNC.l| 00000360: 0B A0 05 42 49 54 20 24 31 43 30 30 00 7C 0B AA |...BIT $1C00.|..| 00000370: 05 42 4D 49 20 54 49 4D 45 4F 55 54 00 9F 0B B4 |.BMI TIMEOUT....| 00000380: 05 4C 44 41 20 24 31 43 30 31 20 20 20 20 20 3B |.LDA $1C01 ;| 00000390: 53 4B 49 50 20 46 49 52 53 54 20 42 59 54 45 00 |SKIP FIRST BYTE.| 000003A0: A7 0B BE 05 43 4C 56 00 B4 0B C8 05 4C 44 59 20 |....CLV.....LDY | 000003B0: 23 24 30 30 00 D6 0B D2 05 A1 42 59 54 45 20 B2 |#$00......BYTE .| 000003C0: 20 AC 20 20 20 20 20 20 3B 87 20 83 20 46 52 4F | . ;. . FRO| 000003D0: 4D 20 44 49 53 4B 00 F3 0B DC 05 42 56 43 20 A1 |M DISK.....BVC .| 000003E0: 42 59 54 45 20 20 20 3B 92 20 81 20 42 59 54 45 |BYTE ;. . BYTE| 000003F0: 20 87 59 00 FB 0B E6 05 43 4C 56 00 21 0C F0 05 | .Y.....CLV.!...| 00000400: 4C 44 41 20 24 31 43 30 31 20 20 20 20 20 3B 93 |LDA $1C01 ;.| 00000410: 20 42 59 54 45 20 46 52 4F 4D 20 83 20 50 4F 52 | BYTE FROM . POR| 00000420: 54 00 4C 0C FA 05 53 54 41 20 24 30 34 30 30 2C |T.L...STA $0400,| 00000430: 59 20 20 20 3B 53 A4 52 45 20 83 20 46 52 4F 4D |Y ;S.RE . FROM| 00000440: 20 24 30 34 30 30 2D 24 30 34 46 46 00 54 0C 04 | $0400-$04FF.T..| 00000450: 06 49 4E 59 00 62 0C 0E 06 42 4E 45 20 A1 42 59 |.INY.b...BNE .BY| 00000460: 54 45 00 80 0C 18 06 4C 44 41 20 23 24 30 31 20 |TE.....LDA #$01 | 00000470: 20 20 20 20 20 3B 30 31 B2 4E 4F 20 45 52 52 B0 | ;01.NO ERR.| 00000480: 00 A2 0C 22 06 80 49 54 20 B2 20 AC 20 20 20 20 |..."..IT . . | 00000490: 20 20 20 20 3B 46 49 4E 49 53 48 20 55 50 20 AF | ;FINISH UP .| 000004A0: 20 80 00 D6 0C 2C 06 53 54 41 20 24 30 30 30 30 | ....,.STA $0000| 000004B0: 20 20 20 20 20 3B 53 A4 52 45 20 45 52 52 B0 20 | ;S.RE ERR. | 000004C0: 43 4F 44 45 20 49 4E 20 43 4F 4D 4D 41 4E 41 44 |CODE IN COMMANAD| 000004D0: 20 51 55 45 55 45 00 F2 0C 36 06 4C 44 41 20 24 | QUEUE...6.LDA $| 000004E0: 31 43 30 43 20 20 20 20 20 3B 4B 49 4C 4C 20 50 |1C0C ;KILL P| 000004F0: 43 52 00 FD 0C 40 06 AF 20 23 24 46 44 00 0B 0D |CR...@.. #$FD...| 00000500: 4A 06 53 54 41 20 24 31 43 30 43 00 2E 0D 54 06 |J.STA $1C0C...T.| 00000510: 4A 4D 50 20 24 46 39 36 45 20 20 20 20 20 3B 52 |JMP $F96E ;R| 00000520: 4F 4D 20 52 4F 55 54 49 4E 45 20 A4 20 80 00 00 |OM ROUTINE . ...| 00000530: 00 |. |
..0.....$4300 ;ROUTINE . . HALF T
RACKS V3.8.$.SEI.C...LDY #$00 ;FIL
L W.K SPACE WITH 00.P.8.LDA #$00...B.CLE
ARIT . ....L.STA $0400,Y ;S.RE 00 AT
$0400.$04FF...V.INY.C.`.BNE CLEARIT...J.
JSR $FE00 ;SET PCR . . MODE...T.LDA
$1C0C...~..A #$0E.....STA $1C0C.:...LDX
$1C00 ;. HEAD IN HALF TRACKS.Q...I
NX ;CHANGE . DEX . MOVE HEAD
OTHER WAY.Y...TXA...... #$03 ;CYCL
E BITS 0 & 1.....STA $0014...D.LDA $1C00
.C.N.. #$FC.P.X..A $0014.....STA $1C00
;. HEAD 1.2 TRACK.....LDX #$AA
;. . HEAD . SETTLE.*...DELAY1 . ..7...L
DY #$00.F...DELAY2 . ..N...DEY.]...BNE D
ELAY2.E.(.DEX...2.BNE DELAY1 ;HEAD SE
TTLED AT HALF TRACK...<.LDX #$00 ;S
ET UP TIMER . SYNC.G.F.LDY #$00.W.P.TIME
OUT . ....Z.DEY...D.BNE .SYNC...N.DEX...
X.BNE .SYNC.1...LDA #$03 ;03.NO SYN
C . NO SYNC . ..=...BNE .IT.^....SYNC
. . ;CHECK . SYNC.L. .BIT $1C00.|..
.BMI TIMEOUT.....LDA $1C01 ;SKIP FIR
ST BYTE.....CLV...H.LDY #$00.V.R..BYTE .
. ;. . FROM DISK.....BVC .BYTE ;
. . BYTE .Y.....CLV.!...LDA $1C01 ;.
BYTE FROM . PORT.L...STA $0400,Y ;S.R
E . FROM $0400-$04FF.T...INY.B...BNE .BY
TE.....LDA #$01 ;01.NO ERR...."..IT
. . ;FINISH UP . ..V.,.STA $0000
;S.RE ERR. CODE IN COMMANAD QUEUE..
.6.LDA $1C0C ;KILL PCR...@.. #$FD...
J.STA $1C0C...T.JMP $F96E ;ROM ROUTI
NE . ....
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