ca65 V2.18 - N/A Main file : DriveFirmware.asm Current file: DriveFirmware.asm 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 000000r 1 .org SLOT*$100 + $C000 00C500 1 ;ID bytes for booting and drive detection 00C500 1 E0 20 cpx #$20 ;ID bytes for ProDOS and the 00C502 1 E0 00 cpx #$00 ; Apple Autostart ROM 00C504 1 E0 03 cpx #$03 ; 00C506 1 00C506 1 A2 50 ldx #SLOT*$10 00C508 1 86 2B stx $2b 00C50A 1 86 43 stx Unit 00C50C 1 00C50C 1 ;force EPROM to second page on boot 00C50C 1 A9 3F lda #$3f ;set all flags high and page 3 of EPROM for menu 00C50E 1 PageJump: 00C50E 1 8D D7 C0 sta OutputFlags 00C511 1 4C 1C C5 jmp Start ;this jump is only called if coming in from PageJump with A=$0f 00C514 1 00C514 1 ;entry points for ProDOS 00C514 1 DriverEntry: 00C514 1 A9 0F lda #$0f ;set all flags high and page 0 of EPROM 00C516 1 8D D7 C0 sta OutputFlags 00C519 1 4C 32 C5 jmp Driver 00C51C 1 00C51C 1 ;load first two blocks and execute to boot 00C51C 1 Start: 00C51C 1 A9 01 lda #$01 ;set read command 00C51E 1 85 42 sta Command 00C520 1 00C520 1 A9 00 lda #$00 ;block 0 00C522 1 85 46 sta BlockLo 00C524 1 85 47 sta BlockHi 00C526 1 85 44 sta BufferLo ;buffer at $800 00C528 1 A9 08 lda #$08 00C52A 1 85 45 sta BufferHi 00C52C 1 20 32 C5 jsr Driver ;get the block 00C52F 1 00C52F 1 4C 01 08 jmp $801 ;execute the block 00C532 1 00C532 1 ; ProDOS Driver code 00C532 1 ; First check that this is the right drive 00C532 1 Driver: 00C532 1 A6 43 ldx Unit 00C534 1 A5 42 lda Command; Check which command is being requested 00C536 1 F0 0C beq GetStatus ;0 = Status command 00C538 1 C9 01 cmp #ReadBlockCommand 00C53A 1 F0 10 beq ReadBlock 00C53C 1 C9 02 cmp #WriteBlockCommand 00C53E 1 F0 46 beq WriteBlock 00C540 1 38 sec ;set carry as we don't support any other commands 00C541 1 A9 53 lda #$53 ;Invalid parameter error 00C543 1 60 rts 00C544 1 00C544 1 ; ProDOS Status Command Handler 00C544 1 GetStatus: 00C544 1 A2 FF ldx #$ff ;low byte number of blocks 00C546 1 A0 FF ldy #$ff ;high byte number of blocks 00C548 1 A9 00 lda #$0 ;zero accumulator and clear carry for success 00C54A 1 18 clc 00C54B 1 60 rts 00C54C 1 00C54C 1 ; ProDOS Read Block Command 00C54C 1 ReadBlock: 00C54C 1 A0 00 ldy #$00 ;Get the current time on each block read for now 00C54E 1 A9 03 lda #GetTimeCommand 00C550 1 20 AE C5 jsr SendByte 00C553 1 getTimeByte: 00C553 1 20 CC C5 jsr GetByte 00C556 1 99 90 BF sta $bf90,y 00C559 1 C8 iny 00C55A 1 C0 04 cpy #$04 00C55C 1 D0 F5 bne getTimeByte 00C55E 1 A9 01 lda #ReadBlockCommand ;read the block after setting the clock 00C560 1 20 AE C5 jsr SendByte 00C563 1 A5 46 lda BlockLo 00C565 1 20 AE C5 jsr SendByte 00C568 1 A5 47 lda BlockHi 00C56A 1 20 AE C5 jsr SendByte 00C56D 1 A0 00 ldy #$0 00C56F 1 20 7D C5 jsr read256 00C572 1 E6 45 inc BufferHi 00C574 1 20 7D C5 jsr read256 00C577 1 C6 45 dec BufferHi 00C579 1 A9 00 lda #$0 ;zero accumulator and clear carry for success 00C57B 1 18 clc 00C57C 1 60 rts 00C57D 1 00C57D 1 read256: 00C57D 1 20 CC C5 jsr GetByte 00C580 1 91 44 sta (BufferLo),y 00C582 1 C8 iny 00C583 1 D0 F8 bne read256 00C585 1 60 rts 00C586 1 00C586 1 ; ProDOS Write Block Command 00C586 1 WriteBlock: 00C586 1 A9 02 lda #WriteBlockCommand 00C588 1 20 AE C5 jsr SendByte 00C58B 1 A5 46 lda BlockLo 00C58D 1 20 AE C5 jsr SendByte 00C590 1 A5 47 lda BlockHi 00C592 1 20 AE C5 jsr SendByte 00C595 1 A0 00 ldy #$0 00C597 1 20 A5 C5 jsr write256 00C59A 1 E6 45 inc BufferHi 00C59C 1 20 A5 C5 jsr write256 00C59F 1 C6 45 dec BufferHi 00C5A1 1 A9 00 lda #$0 ;zero accumulator and clear carry for success 00C5A3 1 18 clc 00C5A4 1 60 rts 00C5A5 1 00C5A5 1 write256: 00C5A5 1 B1 44 lda (BufferLo),y 00C5A7 1 20 AE C5 jsr SendByte 00C5AA 1 C8 iny 00C5AB 1 D0 F8 bne write256 00C5AD 1 60 rts 00C5AE 1 00C5AE 1 SendByte: 00C5AE 1 48 pha 00C5AF 1 waitWrite: 00C5AF 1 AD DB C0 lda InputFlags 00C5B2 1 2A rol 00C5B3 1 2A rol 00C5B4 1 B0 F9 bcs waitWrite 00C5B6 1 68 pla 00C5B7 1 8D DD C0 sta OutputByte 00C5BA 1 A9 0E lda #$0e ; set bit 0 low to indicate write started 00C5BC 1 8D D7 C0 sta OutputFlags 00C5BF 1 finishWrite: 00C5BF 1 AD DB C0 lda InputFlags 00C5C2 1 2A rol 00C5C3 1 2A rol 00C5C4 1 90 F9 bcc finishWrite 00C5C6 1 A9 0F lda #$0f 00C5C8 1 8D D7 C0 sta OutputFlags 00C5CB 1 60 rts 00C5CC 1 00C5CC 1 GetByte: 00C5CC 1 A9 0D lda #$0d ;set read flag low 00C5CE 1 8D D7 C0 sta OutputFlags 00C5D1 1 waitRead: 00C5D1 1 AD DB C0 lda InputFlags 00C5D4 1 2A rol 00C5D5 1 B0 FA bcs waitRead 00C5D7 1 AD DE C0 lda InputByte 00C5DA 1 48 pha 00C5DB 1 A9 0F lda #$0f ;set all flags high 00C5DD 1 8D D7 C0 sta OutputFlags 00C5E0 1 finishRead: 00C5E0 1 AD DB C0 lda InputFlags 00C5E3 1 2A rol 00C5E4 1 90 FA bcc finishRead 00C5E6 1 68 pla 00C5E7 1 end: 00C5E7 1 60 rts 00C5E8 1 00C5E8 1 00 00 00 00 .repeat 251-