tim@amdcad.UUCP (Tim Olson) (07/01/86)
"Beneath Apple ProDOS" by Don Worth and Pieter Lechner includes the patches needed to convert ProDOS to work with 40-track drives. However, these patches are for 1.0.1. I am listing the code I found around the patch area in hopes that this code did not change from 1.0.1 to 1.1.1. Therefore, all you have to do is search for the corresponding code in 1.1.1. and patch the correct locations. First, we must patch the driver to recognize 40-track drives: BLOAD PRODOS,TSYS,A$2000 CALL -151 520D:39 3D0G BSAVE PRODOS,TSYS,A$2000 For those running 1.1.1, the code around the patch area is: 5200- A5 46 LDA $46 5202- A6 47 LDX $47 5204- 8E 56 FB STX $FB56 5207- F0 07 BEQ $5210 5209- CA DEX 520A- D0 2A BNE $5236 520C- C9 18 CMP #$18 <-- # blocks mod 256 (change to #$39) 520E- B0 26 BCS $5236 5210- A0 05 LDY #$05 5212- 0A ASL 5213- 2E 56 FB ROL $FB56 5216- 88 DEY 5217- D0 F9 BNE $5212 5219- 0A ASL 521A- 90 02 BCC $521E 521C- 09 10 ORA #$10 521E- 4A LSR 521F- 4A LSR 5220- 4A LSR 5221- 4A LSR Next, we must patch the FILER to create new 40-track diskettes: BLOAD FILER,TSYS,A$2000 CALL -151 4244:39 79F4:28 3D0G BSAVE FILER,TSYS,A$2000 Code around the patch areas: 423A- A5 AC LDA $AC 423C- 8D 98 42 STA $4298 423F- A5 AA LDA $AA 4241- D0 06 BNE $4249 4243- A9 18 LDA #$18 <-- # blocks mod 256 (change to #$39) 4245- A2 01 LDX #$01 4247- D0 25 BNE $426E 4249- AD 98 42 LDA $4298 424C- 09 C0 ORA #$C0 424E- 85 70 STA $70 4250- A9 FC LDA #$FC --------------------------------------------------- 79EF- E6 D1 INC $D1 79F1- A5 D1 LDA $D1 79F3- C9 23 CMP #$23 <-- # of tracks (change to #$28) 79F5- 90 8B BCC $7982 79F7- A9 00 LDA #$00 79F9- 48 PHA Good luck! Tim Olson Advanced Micro Devices ihnp4!amdcad!tim