Apple2-IO-RPi/Firmware/Driver.lst
2020-12-12 23:26:16 -05:00

179 lines
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ca65 V2.19 - Git 59c58ac
Main file : Driver.asm
Current file: Driver.asm
000000r 1 ; ProDOS Global Page
000000r 1 Device5S1 = $bf1a ;POINTER FOR SLOT 5 DRIVE 1 DRIVER
000000r 1 DeviceCount = $bf31 ;DEVICE COUNT -1
000000r 1 DeviceList = $bf32 ;DEVICE LIST
000000r 1
000000r 1 ; ProDOS Zero Page
000000r 1 Command = $42 ;ProDOS Command
000000r 1 Unit = $43 ;ProDOS unit (SDDD0000)
000000r 1 BufferLo = $44
000000r 1 BufferHi = $45
000000r 1 BlockLo = $46
000000r 1 BlockHi = $47
000000r 1
000000r 1 ; ProDOS Error Codes
000000r 1 IOError = $27
000000r 1 NoDevice = $28
000000r 1 WriteProtect = $2B
000000r 1
000000r 1 SlotDrive = $50
000000r 1 InputByte = $c0de
000000r 1 OutputByte = $c0dd
000000r 1 ReadBlockCommand = $01
000000r 1 WriteBlockCommand = $02
000000r 1 NibbleStorage = $1d
000000r 1
000000r 1 .org $1000
001000 1
001000 1 ; Register the driver with ProDOS
001000 1 A9 16 lda #<Driver
001002 1 8D 1A BF sta Device5S1
001005 1 A9 10 lda #>Driver
001007 1 8D 1B BF sta Device5S1+1
00100A 1 ; Add the drive to the device list
00100A 1 EE 31 BF inc DeviceCount
00100D 1 AD 31 BF lda DeviceCount
001010 1 A0 50 ldy #SlotDrive
001012 1 99 32 BF sta DeviceList,y
001015 1 60 rts
001016 1
001016 1 ; ProDOS Driver code
001016 1 ; First check that this is the right drive
001016 1 Driver:
001016 1 A5 43 lda Unit
001018 1 C9 50 cmp #SlotDrive
00101A 1 F0 04 beq DoCommand ;correct device, so proceed
00101C 1 38 sec ;set carry as ProDOS treats this as an error
00101D 1 A9 28 lda #NoDevice ;put the error code in accumulator for ProDOS
00101F 1 60 rts
001020 1
001020 1 ; Check which command is being requested
001020 1 DoCommand:
001020 1 A5 42 lda Command
001022 1 F0 0C beq GetStatus ;0 = Status command
001024 1 C9 01 cmp #ReadBlockCommand
001026 1 F0 10 beq ReadBlock
001028 1 C9 02 cmp #WriteBlockCommand
00102A 1 F0 34 beq WriteBlock
00102C 1 38 sec ;set carry as we don't support any other commands
00102D 1 A9 53 lda #$53 ;Invalid parameter error
00102F 1 60 rts
001030 1
001030 1 ; ProDOS Status Command Handler
001030 1 GetStatus:
001030 1 A2 FF ldx #$ff ;low byte number of blocks
001032 1 A0 FF ldy #$ff ;high byte number of blocks
001034 1 A9 00 lda #$0 ;zero accumulator and clear carry for success
001036 1 18 clc
001037 1 60 rts
001038 1
001038 1 ; ProDOS Read Block Command
001038 1 ReadBlock:
001038 1 A9 01 lda #ReadBlockCommand
00103A 1 20 88 10 jsr SendByte
00103D 1 A5 46 lda BlockLo
00103F 1 20 88 10 jsr SendByte
001042 1 A5 47 lda BlockHi
001044 1 20 88 10 jsr SendByte
001047 1 A0 00 ldy #$0
001049 1 20 57 10 jsr read256
00104C 1 E6 45 inc BufferHi
00104E 1 20 57 10 jsr read256
001051 1 C6 45 dec BufferHi
001053 1 A9 00 lda #$0 ;zero accumulator and clear carry for success
001055 1 18 clc
001056 1 60 rts
001057 1
001057 1 read256:
001057 1 20 B0 10 jsr GetByte
00105A 1 91 44 sta (BufferLo),y
00105C 1 C8 iny
00105D 1 D0 F8 bne read256
00105F 1 60 rts
001060 1
001060 1 ; ProDOS Write Block Command
001060 1 WriteBlock:
001060 1 A9 02 lda #WriteBlockCommand
001062 1 20 88 10 jsr SendByte
001065 1 A5 46 lda BlockLo
001067 1 20 88 10 jsr SendByte
00106A 1 A5 47 lda BlockHi
00106C 1 20 88 10 jsr SendByte
00106F 1 A0 00 ldy #$0
001071 1 20 7F 10 jsr write256
001074 1 E6 45 inc BufferHi
001076 1 20 7F 10 jsr write256
001079 1 C6 45 dec BufferHi
00107B 1 A9 00 lda #$0 ;zero accumulator and clear carry for success
00107D 1 18 clc
00107E 1 60 rts
00107F 1
00107F 1 write256:
00107F 1 B1 44 lda (BufferLo),y
001081 1 20 88 10 jsr SendByte
001084 1 C8 iny
001085 1 D0 F8 bne write256
001087 1 60 rts
001088 1
001088 1 SendByte:
001088 1 48 pha
001089 1 4A lsr
00108A 1 4A lsr
00108B 1 4A lsr
00108C 1 4A lsr
00108D 1 20 95 10 jsr SendNibble
001090 1 68 pla
001091 1 20 95 10 jsr SendNibble
001094 1 60 rts
001095 1
001095 1 SendNibble:
001095 1 29 0F and #$0F
001097 1 09 70 ora #$70 ;Write bit low
001099 1 48 pha
00109A 1 waitWrite:
00109A 1 AD DE C0 lda InputByte
00109D 1 0A asl ;Second highest bit goes low when ready
00109E 1 30 FA bmi waitWrite
0010A0 1 68 pla
0010A1 1 8D DD C0 sta OutputByte
0010A4 1 finishWrite:
0010A4 1 AD DE C0 lda InputByte
0010A7 1 0A asl
0010A8 1 10 FA bpl finishWrite
0010AA 1 A9 FF lda #$FF
0010AC 1 8D DD C0 sta OutputByte
0010AF 1 60 rts
0010B0 1
0010B0 1 GetByte:
0010B0 1 20 C1 10 jsr GetNibble
0010B3 1 0A asl
0010B4 1 0A asl
0010B5 1 0A asl
0010B6 1 0A asl
0010B7 1 85 1D sta NibbleStorage
0010B9 1 20 C1 10 jsr GetNibble
0010BC 1 29 0F and #$0f
0010BE 1 05 1D ora NibbleStorage
0010C0 1 60 rts
0010C1 1
0010C1 1 GetNibble:
0010C1 1 A9 B0 lda #$b0 ;set read flag low
0010C3 1 8D DD C0 sta OutputByte
0010C6 1 waitRead:
0010C6 1 AD DE C0 lda InputByte
0010C9 1 30 FB bmi waitRead
0010CB 1 09 F0 ora #$f0 ;set all flags high
0010CD 1 8D DD C0 sta OutputByte
0010D0 1 48 pha
0010D1 1 finishRead:
0010D1 1 AD DE C0 lda InputByte
0010D4 1 10 FB bpl finishRead
0010D6 1 68 pla
0010D7 1 60 rts
0010D8 1
0010D8 1