ca65 V2.18 - Debian 2.19-1 Main file : DriveFirmware.asm Current file: DriveFirmware.asm 000000r 1 ; Copyright Terence J. Boldt (c)2020-2024 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 D8 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 D8 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 2C FB C0 bit InputFlags 00C7C3 1 70 FB bvs SendByte 00C7C5 1 8D FD C0 sta OutputByte 00C7C8 1 .if HW_TYPE = 0 00C7C8 1 A9 0E lda #$0e ; set bit 0 low to indicate write started 00C7CA 1 8D F7 C0 sta OutputFlags 00C7CD 1 finishWrite: 00C7CD 1 2C FB C0 bit InputFlags 00C7D0 1 50 FB bvc finishWrite 00C7D2 1 A9 0F lda #$0f 00C7D4 1 8D F7 C0 sta OutputFlags 00C7D7 1 .endif 00C7D7 1 60 rts 00C7D8 1 00C7D8 1 GetByte: 00C7D8 1 .if HW_TYPE = 0 00C7D8 1 A9 0D lda #$0d ;set read flag low 00C7DA 1 8D F7 C0 sta OutputFlags 00C7DD 1 .endif 00C7DD 1 waitRead: 00C7DD 1 2C FB C0 bit InputFlags 00C7E0 1 30 FB bmi waitRead 00C7E2 1 AD FE C0 lda InputByte 00C7E5 1 .if HW_TYPE = 0 00C7E5 1 48 pha 00C7E6 1 A9 0F lda #$0f ;set all flags high 00C7E8 1 8D F7 C0 sta OutputFlags 00C7EB 1 finishRead: 00C7EB 1 2C FB C0 bit InputFlags 00C7EE 1 10 FB bpl finishRead 00C7F0 1 68 pla 00C7F1 1 .endif 00C7F1 1 end: 00C7F1 1 60 rts 00C7F2 1 00C7F2 1 00 00 00 00 .repeat 251-