mirror of
https://github.com/tjboldt/ProDOS-ROM-Drive.git
synced 2024-11-28 11:51:12 +00:00
202 lines
8.9 KiB
Plaintext
202 lines
8.9 KiB
Plaintext
|
ca65 V2.18 - N/A
|
||
|
|
Main file : Firmware.asm
|
||
|
|
Current file: Firmware.asm
|
||
|
|
|
||
|
|
000000r 1 writeLatchHigh = $C081
|
||
|
|
000000r 1 writeLatchLow = $C080
|
||
|
|
000000r 1
|
||
|
|
000000r 1 ;temp variables becasue 6502 only has 3 registers
|
||
|
|
000000r 1 highLatch = $F8
|
||
|
|
000000r 1 lowLatch = $F9
|
||
|
|
000000r 1 tempY = $FE
|
||
|
|
000000r 1 blockHalfCounter = $FF
|
||
|
|
000000r 1
|
||
|
|
000000r 1 ;ProDOS defines
|
||
|
|
000000r 1 command = $42 ;ProDOS command
|
||
|
|
000000r 1 unit = $43 ;7=drive 6-4=slot 3-0=not used
|
||
|
|
000000r 1 buflo = $44 ;low address of buffer
|
||
|
|
000000r 1 bufhi = $45 ;hi address of buffer
|
||
|
|
000000r 1 blklo = $46 ;low block
|
||
|
|
000000r 1 blkhi = $47 ;hi block
|
||
|
|
000000r 1 ioerr = $27 ;I/O error code
|
||
|
|
000000r 1 nodev = $28 ;no device connected
|
||
|
|
000000r 1 wperr = $2B ;write protect error
|
||
|
|
000000r 1
|
||
|
|
000000r 1 ;for relocatable code, address to jump to instead of JSR absolute + RTS
|
||
|
|
000000r 1 jumpAddressLo = $FA
|
||
|
|
000000r 1 jumpAddressHi = $FB
|
||
|
|
000000r 1 ioAddressLo = $FC
|
||
|
|
000000r 1 ioAddressHi = $FD
|
||
|
|
000000r 1 knownRts = $FF58
|
||
|
|
000000r 1
|
||
|
|
000000r 1 .org $C700
|
||
|
|
00C700 1 ;code is relocatable
|
||
|
|
00C700 1 ; but set to $c700 for
|
||
|
|
00C700 1 ; readability
|
||
|
|
00C700 1
|
||
|
|
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 E0 3C cpx #$3C ;this one for older II's
|
||
|
|
00C708 1
|
||
|
|
00C708 1 ;zero out block numbers and buffer address
|
||
|
|
00C708 1 84 44 sty buflo
|
||
|
|
00C70A 1 84 46 sty blklo
|
||
|
|
00C70C 1 84 47 sty blkhi
|
||
|
|
00C70E 1 C8 iny ;set command = 1 for read block
|
||
|
|
00C70F 1 84 42 sty command
|
||
|
|
00C711 1 84 FA sty jumpAddressLo ;$01 of $0801 where boot code starts
|
||
|
|
00C713 1 20 58 FF jsr knownRts ;jump to known RTS to get our address from the stack
|
||
|
|
00C716 1 BA tsx
|
||
|
|
00C717 1 BD 00 01 lda $0100,x ;this for example would be $C7 in slot 7
|
||
|
|
00C71A 1 85 45 sta bufhi ;keep the slot here
|
||
|
|
00C71C 1 0A asl
|
||
|
|
00C71D 1 0A asl
|
||
|
|
00C71E 1 0A asl
|
||
|
|
00C71F 1 0A asl
|
||
|
|
00C720 1 AA tax
|
||
|
|
00C721 1
|
||
|
|
00C721 1 ;display copyright message
|
||
|
|
00C721 1 A0 C1 ldy #<text
|
||
|
|
00C723 1 B1 44 drawtxt: lda (buflo),y
|
||
|
|
00C725 1 99 D0 07 sta $07D0,y ;put text on last line
|
||
|
|
00C728 1 C8 iny
|
||
|
|
00C729 1 D0 F8 bne drawtxt
|
||
|
|
00C72B 1
|
||
|
|
00C72B 1 ;load block 0000 at $0800
|
||
|
|
00C72B 1 A9 08 lda #$08
|
||
|
|
00C72D 1 85 45 sta bufhi
|
||
|
|
00C72F 1 85 FB sta jumpAddressHi
|
||
|
|
00C731 1 86 43 stx unit
|
||
|
|
00C733 1 D0 08 bne start
|
||
|
|
00C735 1 entry:
|
||
|
|
00C735 1 A9 58 lda #<knownRts
|
||
|
|
00C737 1 85 FA sta jumpAddressLo
|
||
|
|
00C739 1 A9 FF lda #>knownRts
|
||
|
|
00C73B 1 85 FB sta jumpAddressHi
|
||
|
|
00C73D 1 start:
|
||
|
|
00C73D 1 A9 C0 lda #$C0
|
||
|
|
00C73F 1 85 FD sta ioAddressHi
|
||
|
|
00C741 1 20 58 FF jsr knownRts
|
||
|
|
00C744 1 BA tsx
|
||
|
|
00C745 1 BD 00 01 lda $0100,x
|
||
|
|
00C748 1 0A asl a
|
||
|
|
00C749 1 0A asl a
|
||
|
|
00C74A 1 0A asl a
|
||
|
|
00C74B 1 0A asl a
|
||
|
|
00C74C 1 AA tax
|
||
|
|
00C74D 1 E4 43 cpx unit ;make sure same as ProDOS
|
||
|
|
00C74F 1 F0 04 beq docmd ;yep, do command
|
||
|
|
00C751 1 38 sec ;nope, set device not connected
|
||
|
|
00C752 1 A9 28 lda #nodev
|
||
|
|
00C754 1 60 rts ;go back to ProDOS
|
||
|
|
00C755 1
|
||
|
|
00C755 1 docmd:
|
||
|
|
00C755 1 A5 42 lda command
|
||
|
|
00C757 1 F0 08 beq getstat ;command 0 is GetStatus
|
||
|
|
00C759 1 C9 01 cmp #$01
|
||
|
|
00C75B 1 F0 0C beq readblk ;command 1 is ReadBlock
|
||
|
|
00C75D 1 38 sec ;Format/Write not permitted
|
||
|
|
00C75E 1 A9 2B lda #wperr ;write protect error
|
||
|
|
00C760 1 60 rts ;go back to ProDOS
|
||
|
|
00C761 1
|
||
|
|
00C761 1 getstat:
|
||
|
|
00C761 1 18 clc ;send back status
|
||
|
|
00C762 1 A9 00 lda #$00 ;good status
|
||
|
|
00C764 1 A2 00 ldx #$00 ;1024 blocks
|
||
|
|
00C766 1 A0 04 ldy #$04 ;
|
||
|
|
00C768 1 60 rts
|
||
|
|
00C769 1
|
||
|
|
00C769 1 readblk:
|
||
|
|
00C769 1 A5 47 lda blkhi ;get hi block
|
||
|
|
00C76B 1 0A asl a ;shift up to top 3 bits
|
||
|
|
00C76C 1 0A asl a ;since that's all the high
|
||
|
|
00C76D 1 0A asl a ;blocks we can handle
|
||
|
|
00C76E 1 0A asl a ;
|
||
|
|
00C76F 1 0A asl a ;
|
||
|
|
00C770 1 85 F8 sta highLatch ;save it in scratch ram 0
|
||
|
|
00C772 1 ;so we can stuff it in the
|
||
|
|
00C772 1 ;high latch later
|
||
|
|
00C772 1 A5 46 lda blklo ;get low block
|
||
|
|
00C774 1 4A lsr a ;shift so we get the top 5
|
||
|
|
00C775 1 4A lsr a ;bits - this also goes in
|
||
|
|
00C776 1 4A lsr a ;the high latch
|
||
|
|
00C777 1 05 F8 ora highLatch ;add it to those top 3 bits
|
||
|
|
00C779 1 85 F8 sta highLatch ;save it back in scratch ram
|
||
|
|
00C77B 1 A5 46 lda blklo ;get low block
|
||
|
|
00C77D 1 0A asl a ;shift it to top 3 bits
|
||
|
|
00C77E 1 0A asl a ;
|
||
|
|
00C77F 1 0A asl a ;
|
||
|
|
00C780 1 0A asl a ;
|
||
|
|
00C781 1 0A asl a ;
|
||
|
|
00C782 1 85 F9 sta lowLatch
|
||
|
|
00C784 1 A9 02 lda #$02
|
||
|
|
00C786 1 85 FF sta blockHalfCounter
|
||
|
|
00C788 1
|
||
|
|
00C788 1 ;This gets 256 bytes from the ROM card
|
||
|
|
00C788 1
|
||
|
|
00C788 1 read256:
|
||
|
|
00C788 1 A0 00 ldy #$00
|
||
|
|
00C78A 1 A5 F8 lda highLatch ;get high latch value
|
||
|
|
00C78C 1 9D 81 C0 sta writeLatchHigh,x ;set high latch for card
|
||
|
|
00C78F 1 loop256:
|
||
|
|
00C78F 1 A5 F9 lda lowLatch
|
||
|
|
00C791 1 9D 80 C0 sta writeLatchLow,x
|
||
|
|
00C794 1 8A txa
|
||
|
|
00C795 1 09 80 ora #$80
|
||
|
|
00C797 1 85 FC sta ioAddressLo
|
||
|
|
00C799 1 loop16:
|
||
|
|
00C799 1 84 FE sty tempY
|
||
|
|
00C79B 1 A0 00 ldy #$00
|
||
|
|
00C79D 1 B1 FC lda (ioAddressLo),y
|
||
|
|
00C79F 1 A4 FE ldy tempY
|
||
|
|
00C7A1 1 91 44 sta (buflo),y
|
||
|
|
00C7A3 1 C8 iny
|
||
|
|
00C7A4 1 E6 FC inc ioAddressLo
|
||
|
|
00C7A6 1 A5 FC lda ioAddressLo
|
||
|
|
00C7A8 1 29 0F and #$0F
|
||
|
|
00C7AA 1 D0 ED bne loop16
|
||
|
|
00C7AC 1 E6 F9 inc lowLatch
|
||
|
|
00C7AE 1 C0 00 cpy #$00
|
||
|
|
00C7B0 1 D0 DD bne loop256
|
||
|
|
00C7B2 1 C6 FF dec blockHalfCounter
|
||
|
|
00C7B4 1 D0 06 bne readnext256
|
||
|
|
00C7B6 1 C6 45 dec bufhi
|
||
|
|
00C7B8 1 18 clc ;clear error code for success
|
||
|
|
00C7B9 1 A9 00 lda #$00
|
||
|
|
00C7BB 1 60 rts ;return to ProDOS
|
||
|
|
00C7BC 1
|
||
|
|
00C7BC 1 readnext256:
|
||
|
|
00C7BC 1 E6 45 inc bufhi
|
||
|
|
00C7BE 1 18 clc
|
||
|
|
00C7BF 1 90 C7 bcc read256
|
||
|
|
00C7C1 1
|
||
|
|
00C7C1 1 ;macro for string with high-bit set
|
||
|
|
00C7C1 1 .macro aschi str
|
||
|
|
00C7C1 1 .repeat .strlen (str), c
|
||
|
|
00C7C1 1 .byte .strat (str, c) | $80
|
||
|
|
00C7C1 1 .endrep
|
||
|
|
00C7C1 1 .endmacro
|
||
|
|
00C7C1 1
|
||
|
|
00C7C1 1 D2 CF CD AD text: aschi "ROM-Drive (c)1998-2021 Terence J. Boldt"
|
||
|
|
00C7C5 1 C4 F2 E9 F6
|
||
|
|
00C7C9 1 E5 A0 A8 E3
|
||
|
|
00C7E8 1 end:
|
||
|
|
00C7E8 1 00 .byte 0
|
||
|
|
00C7E9 1
|
||
|
|
00C7E9 1 ; These bytes need to be at the top of the 256 byte firmware as ProDOS
|
||
|
|
00C7E9 1 ; uses these to find the entry point and drive capabilities
|
||
|
|
00C7E9 1
|
||
|
|
00C7E9 1 00 00 00 00 .repeat 251-<end
|
||
|
|
00C7ED 1 00 00 00 00
|
||
|
|
00C7F1 1 00 00 00 00
|
||
|
|
00C7FC 1 .byte 0
|
||
|
|
00C7FC 1 .endrepeat
|
||
|
|
00C7FC 1
|
||
|
|
00C7FC 1 00 00 .byte 0,0 ;0000 blocks = check status
|
||
|
|
00C7FE 1 03 .byte 3 ;bit 0=read 1=status
|
||
|
|
00C7FF 1 35 .byte entry&$00FF ;low byte of entry
|
||
|
|
00C800 1
|
||
|
|
00C800 1
|