mirror of
https://github.com/tjboldt/Apple2-IO-RPi.git
synced 2024-12-18 06:29:31 +00:00
215 lines
8.8 KiB
Plaintext
215 lines
8.8 KiB
Plaintext
ca65 V2.18 - Raspbian 2.19-1
|
|
Main file : DriveFirmware.asm
|
|
Current file: DriveFirmware.asm
|
|
|
|
000000r 1 ; Copyright Terence J. Boldt (c)2020-2023
|
|
000000r 1 ; Use of this source code is governed by an MIT
|
|
000000r 1 ; license that can be found in the LICENSE file.
|
|
000000r 1
|
|
000000r 1 ; This file contains the source for the firmware
|
|
000000r 1 ; that allows the Apple II to boot from the card
|
|
000000r 1 ; and for ProDOS to recognize the card as two
|
|
000000r 1 ; hard drivers
|
|
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 InputByte = $c08e+SLOT*$10
|
|
000000r 1 OutputByte = $c08d+SLOT*$10
|
|
000000r 1 InputFlags = $c08b+SLOT*$10
|
|
000000r 1 OutputFlags = $c087+SLOT*$10
|
|
000000r 1
|
|
000000r 1 ReadBlockCommand = $01
|
|
000000r 1 WriteBlockCommand = $02
|
|
000000r 1 GetTimeCommand = $03
|
|
000000r 1 ChangeDriveCommand = $04
|
|
000000r 1 ExecCommand = $05
|
|
000000r 1 LoadFileCommand = $06
|
|
000000r 1 SaveFileCommand = $07
|
|
000000r 1 MenuCommand = $08
|
|
000000r 1
|
|
000000r 1 .org SLOT*$100 + $C000
|
|
00C700 1 ;ID bytes for booting and drive detection
|
|
00C700 1 E0 20 cpx #$20 ;ID bytes for ProDOS and the
|
|
00C702 1 E0 00 cpx #$00 ; Apple Autostart ROM
|
|
00C704 1 E0 03 cpx #$03 ;
|
|
00C706 1
|
|
00C706 1 A2 70 ldx #SLOT*$10
|
|
00C708 1 86 2B stx $2b
|
|
00C70A 1 86 43 stx Unit
|
|
00C70C 1
|
|
00C70C 1 ;force EPROM to second page on boot
|
|
00C70C 1 A9 3F lda #$3f ;set all flags high and page 3 of EPROM for menu
|
|
00C70E 1 PageJump:
|
|
00C70E 1 8D F7 C0 sta OutputFlags
|
|
00C711 1 4C 1C C7 jmp Start ;this jump is only called if coming in from PageJump with A=$0f
|
|
00C714 1
|
|
00C714 1 ;entry points for ProDOS
|
|
00C714 1 DriverEntry:
|
|
00C714 1 A9 0F lda #$0f ;set all flags high and page 0 of EPROM
|
|
00C716 1 8D F7 C0 sta OutputFlags
|
|
00C719 1 4C 32 C7 jmp Driver
|
|
00C71C 1
|
|
00C71C 1 ;load first two blocks and execute to boot
|
|
00C71C 1 Start:
|
|
00C71C 1 A9 01 lda #$01 ;set read command
|
|
00C71E 1 85 42 sta Command
|
|
00C720 1
|
|
00C720 1 A9 00 lda #$00 ;block 0
|
|
00C722 1 85 46 sta BlockLo
|
|
00C724 1 85 47 sta BlockHi
|
|
00C726 1 85 44 sta BufferLo ;buffer at $800
|
|
00C728 1 A9 08 lda #$08
|
|
00C72A 1 85 45 sta BufferHi
|
|
00C72C 1 20 32 C7 jsr Driver ;get the block
|
|
00C72F 1
|
|
00C72F 1 4C 01 08 jmp $801 ;execute the block
|
|
00C732 1
|
|
00C732 1 ; ProDOS Driver code
|
|
00C732 1 ; First check that this is the right drive
|
|
00C732 1 Driver:
|
|
00C732 1 A6 43 ldx Unit
|
|
00C734 1 A5 42 lda Command; Check which command is being requested
|
|
00C736 1 F0 0C beq GetStatus ;0 = Status command
|
|
00C738 1 C9 01 cmp #ReadBlockCommand
|
|
00C73A 1 F0 10 beq ReadBlockAndSetTime
|
|
00C73C 1 C9 02 cmp #WriteBlockCommand
|
|
00C73E 1 F0 54 beq WriteBlock
|
|
00C740 1 38 sec ;set carry as we don't support any other commands
|
|
00C741 1 A9 53 lda #$53 ;Invalid parameter error
|
|
00C743 1 60 rts
|
|
00C744 1
|
|
00C744 1 ; ProDOS Status Command Handler
|
|
00C744 1 GetStatus:
|
|
00C744 1 A2 FF ldx #$ff ;low byte number of blocks
|
|
00C746 1 A0 FF ldy #$ff ;high byte number of blocks
|
|
00C748 1 A9 00 lda #$0 ;zero accumulator and clear carry for success
|
|
00C74A 1 18 clc
|
|
00C74B 1 60 rts
|
|
00C74C 1
|
|
00C74C 1 ; ProDOS Read Block Command
|
|
00C74C 1 ReadBlockAndSetTime:
|
|
00C74C 1 A5 47 lda BlockHi ; only get the time if block 0002
|
|
00C74E 1 D0 18 bne readBlock
|
|
00C750 1 A5 46 lda BlockLo
|
|
00C752 1 C9 02 cmp #$02
|
|
00C754 1 D0 12 bne readBlock
|
|
00C756 1 A0 00 ldy #$00 ;Get the current time on each block read for now
|
|
00C758 1 A9 03 lda #GetTimeCommand
|
|
00C75A 1 20 C0 C7 jsr SendByte
|
|
00C75D 1 getTimeByte:
|
|
00C75D 1 20 DE C7 jsr GetByte
|
|
00C760 1 99 90 BF sta $bf90,y
|
|
00C763 1 C8 iny
|
|
00C764 1 C0 04 cpy #$04
|
|
00C766 1 D0 F5 bne getTimeByte
|
|
00C768 1 readBlock:
|
|
00C768 1 A9 01 lda #ReadBlockCommand ;read the block after setting the clock
|
|
00C76A 1 20 C0 C7 jsr SendByte
|
|
00C76D 1 A5 46 lda BlockLo
|
|
00C76F 1 20 C0 C7 jsr SendByte
|
|
00C772 1 A5 47 lda BlockHi
|
|
00C774 1 20 C0 C7 jsr SendByte
|
|
00C777 1 8A txa
|
|
00C778 1 20 C0 C7 jsr SendByte
|
|
00C77B 1 A0 00 ldy #$0
|
|
00C77D 1 20 8B C7 jsr read256
|
|
00C780 1 E6 45 inc BufferHi
|
|
00C782 1 20 8B C7 jsr read256
|
|
00C785 1 C6 45 dec BufferHi
|
|
00C787 1 A9 00 lda #$0 ;zero accumulator and clear carry for success
|
|
00C789 1 18 clc
|
|
00C78A 1 60 rts
|
|
00C78B 1
|
|
00C78B 1 read256:
|
|
00C78B 1 20 DE C7 jsr GetByte
|
|
00C78E 1 91 44 sta (BufferLo),y
|
|
00C790 1 C8 iny
|
|
00C791 1 D0 F8 bne read256
|
|
00C793 1 60 rts
|
|
00C794 1
|
|
00C794 1 ; ProDOS Write Block Command
|
|
00C794 1 WriteBlock:
|
|
00C794 1 A9 02 lda #WriteBlockCommand
|
|
00C796 1 20 C0 C7 jsr SendByte
|
|
00C799 1 A5 46 lda BlockLo
|
|
00C79B 1 20 C0 C7 jsr SendByte
|
|
00C79E 1 A5 47 lda BlockHi
|
|
00C7A0 1 20 C0 C7 jsr SendByte
|
|
00C7A3 1 8A txa
|
|
00C7A4 1 20 C0 C7 jsr SendByte
|
|
00C7A7 1 A0 00 ldy #$0
|
|
00C7A9 1 20 B7 C7 jsr write256
|
|
00C7AC 1 E6 45 inc BufferHi
|
|
00C7AE 1 20 B7 C7 jsr write256
|
|
00C7B1 1 C6 45 dec BufferHi
|
|
00C7B3 1 A9 00 lda #$0 ;zero accumulator and clear carry for success
|
|
00C7B5 1 18 clc
|
|
00C7B6 1 60 rts
|
|
00C7B7 1
|
|
00C7B7 1 write256:
|
|
00C7B7 1 B1 44 lda (BufferLo),y
|
|
00C7B9 1 20 C0 C7 jsr SendByte
|
|
00C7BC 1 C8 iny
|
|
00C7BD 1 D0 F8 bne write256
|
|
00C7BF 1 60 rts
|
|
00C7C0 1
|
|
00C7C0 1 SendByte:
|
|
00C7C0 1 48 pha
|
|
00C7C1 1 waitWrite:
|
|
00C7C1 1 AD FB C0 lda InputFlags
|
|
00C7C4 1 2A rol
|
|
00C7C5 1 2A rol
|
|
00C7C6 1 B0 F9 bcs waitWrite
|
|
00C7C8 1 68 pla
|
|
00C7C9 1 8D FD C0 sta OutputByte
|
|
00C7CC 1 A9 0E lda #$0e ; set bit 0 low to indicate write started
|
|
00C7CE 1 8D F7 C0 sta OutputFlags
|
|
00C7D1 1 finishWrite:
|
|
00C7D1 1 AD FB C0 lda InputFlags
|
|
00C7D4 1 2A rol
|
|
00C7D5 1 2A rol
|
|
00C7D6 1 90 F9 bcc finishWrite
|
|
00C7D8 1 A9 0F lda #$0f
|
|
00C7DA 1 8D F7 C0 sta OutputFlags
|
|
00C7DD 1 60 rts
|
|
00C7DE 1
|
|
00C7DE 1 GetByte:
|
|
00C7DE 1 A9 0D lda #$0d ;set read flag low
|
|
00C7E0 1 8D F7 C0 sta OutputFlags
|
|
00C7E3 1 waitRead:
|
|
00C7E3 1 AD FB C0 lda InputFlags
|
|
00C7E6 1 2A rol
|
|
00C7E7 1 B0 FA bcs waitRead
|
|
00C7E9 1 AD FE C0 lda InputByte
|
|
00C7EC 1 48 pha
|
|
00C7ED 1 A9 0F lda #$0f ;set all flags high
|
|
00C7EF 1 8D F7 C0 sta OutputFlags
|
|
00C7F2 1 finishRead:
|
|
00C7F2 1 AD FB C0 lda InputFlags
|
|
00C7F5 1 2A rol
|
|
00C7F6 1 90 FA bcc finishRead
|
|
00C7F8 1 68 pla
|
|
00C7F9 1 end:
|
|
00C7F9 1 60 rts
|
|
00C7FA 1
|
|
00C7FA 1 00 00 .repeat 251-<end
|
|
00C7FC 1 .byte 0
|
|
00C7FC 1 .endrepeat
|
|
00C7FC 1
|
|
00C7FC 1 00 00 .byte 0,0 ;0000 blocks = check status
|
|
00C7FE 1 17 .byte 23 ;bit set(0=status 1=read 2=write) unset(3=format, 4/5=number of volumes, 6=interruptable, 7=removable)
|
|
00C7FF 1 14 .byte DriverEntry&$00FF ;low byte of entry
|
|
00C800 1
|
|
00C800 1
|