Update assembler code to work with modern version of cc65 tools

This commit is contained in:
Terence Boldt 2020-11-30 21:36:10 -05:00
parent 336615f3af
commit 9667fda1e4
4 changed files with 87 additions and 57 deletions

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@ -3,59 +3,69 @@
;This allows the card to work in any slot without
;having to write space consuming relocatable code.
;Install cc65 (on Ubuntu this is: sudo apt install cc65)
;Execute the following commands to generate the binary:
;ca65 Firmware.asm -D SLOT1 -o slot1.o
;ca65 Firmware.asm -D SLOT2 -o slot2.o
;ca65 Firmware.asm -D SLOT3 -o slot3.o
;ca65 Firmware.asm -D SLOT4 -o slot4.o
;ca65 Firmware.asm -D SLOT5 -o slot5.o
;ca65 Firmware.asm -D SLOT6 -o slot6.o
;ca65 Firmware.asm -D SLOT7 -o slot7.o
;ld65 -t none slot1.o slot2.o slot3.o slot4.o slot5.o slot6.o slot7.o -o Firmware.bin
;Determine which slot we want by command-line define
if SLOT1
slot equ $01
if SLOT2
slot equ $02
if SLOT3
slot equ $03
if SLOT4
slot equ $04
if SLOT5
slot equ $05
if SLOT6
slot equ $06
if SLOT7
slot equ $07
.ifdef SLOT1
slot = $01
.ifdef SLOT2
slot = $02
.ifdef SLOT3
slot = $03
.ifdef SLOT4
slot = $04
.ifdef SLOT5
slot = $05
.ifdef SLOT6
slot = $06
.ifdef SLOT7
slot = $07
;Calculate I/O addresses for this slot
slotwh equ $C081+slot*$10
slotwl equ $C080+slot*$10
slotrd equ $C080+slot*$10
sdrive equ slot*$10
slotwh = $C081+slot*$10
slotwl = $C080+slot*$10
slotrd = $C080+slot*$10
sdrive = slot*$10
sram0 equ $478+slot
sram1 equ $4F8+slot
sram2 equ $578+slot
sram3 equ $5F8+slot
sram4 equ $678+slot
sram5 equ $6F8+slot
sram6 equ $778+slot
sram7 equ $7F8+slot
sram0 = $478+slot
sram1 = $4F8+slot
sram2 = $578+slot
sram3 = $5F8+slot
sram4 = $678+slot
sram5 = $6F8+slot
sram6 = $778+slot
sram7 = $7F8+slot
;ProDOS defines
command equ $42 ;ProDOS command
unit equ $43 ;7=drive 6-4=slot 3-0=not used
buflo equ $44 ;low address of buffer
bufhi equ $45 ;hi address of buffer
blklo equ $46 ;low block
blkhi equ $47 ;hi block
ioerr equ $27 ;I/O error code
nodev equ $28 ;no device connected
wperr equ $2B ;write protect error
command = $42 ;ProDOS command
unit = $43 ;7=drive 6-4=slot 3-0=not used
buflo = $44 ;low address of buffer
bufhi = $45 ;hi address of buffer
blklo = $46 ;low block
blkhi = $47 ;hi block
ioerr = $27 ;I/O error code
nodev = $28 ;no device connected
wperr = $2B ;write protect error
org $C000+slot*$100
.org $C000+slot*$100
;code is non-relocatable
; but duplicated seven times,
; once for each slot
@ -68,7 +78,7 @@ wperr equ $2B ;write protect error
;display copyright message
ldy #$00
drawtxt lda text,y
drawtxt: lda text,y
beq boot ;check for NULL
ora #$80 ;make it visible to the Apple
sta $07D0,y ;put text on last line
@ -76,7 +86,7 @@ drawtxt lda text,y
bpl drawtxt
;load first two blocks and execute to boot
boot lda #$01 ;set read command
boot: lda #$01 ;set read command
sta command
lda #sdrive ;set slot and unit
sta unit
@ -101,14 +111,14 @@ boot lda #$01 ;set read command
jmp $801 ;execute the block
;This is the ProDOS entry point for this card
entry lda #sdrive ;unit number is $n0 - n = slot
entry: lda #sdrive ;unit number is $n0 - n = slot
cmp unit ;make sure same as ProDOS
beq docmd ;yep, do command
sec ;nope, set device not connected
lda #nodev
rts ;go back to ProDOS
docmd lda command ;get ProDOS command
docmd: lda command ;get ProDOS command
beq getstat ;command 0 is GetStatus
cmp #$01 ;
beq readblk ;command 1 is ReadBlock
@ -116,13 +126,13 @@ docmd lda command ;get ProDOS command
lda #wperr ;write protect error
rts ;go back to ProDOS
getstat clc ;send back status
getstat: clc ;send back status
lda #$00 ;good status
ldx #$00 ;1024 blocks
ldy #$04 ;
readblk lda blkhi ;get hi block
readblk: lda blkhi ;get hi block
asl a ;shift up to top 3 bits
asl a ;since that's all the high
asl a ;blocks we can handle
@ -165,15 +175,15 @@ readblk lda blkhi ;get hi block
;This gets 256 bytes from the ROM card
;assuming high latch value is in sram0
;and low latch value is in sram1
get256 ldy #$00 ;clear buffer counter
get256: ldy #$00 ;clear buffer counter
lda sram0 ;get high latch value
sta slotwh ;set high latch for card
loop256 ldx #$00 ;clear port counter
loop256: ldx #$00 ;clear port counter
lda sram1 ;get low latch value
sta slotwl ;set low latch
loop16 lda slotrd,x ;get a byte
loop16: lda slotrd,x ;get a byte
sta (buflo),y ;write into the buffer
@ -186,10 +196,19 @@ loop16 lda slotrd,x ;get a byte
text db "ROM-Drive (c)1998-2019 Terence J. Boldt", 0
text: .byte "ROM-Drive (c)1998-2019 Terence J. Boldt", 0
org $C0FC+slot*$100
db 0,0 ;0000 blocks = check status
db 3 ;bit 0=read 1=status
db entry&$00FF ;low byte of entry
; These bytes need to be at the top of the 256 byte firmware as ProDOS
; uses these to find the entry point and drive capabilities
; In 1998, cc65 used to allow this but now with ld65 removes the padded bytes
; .org $C0FC+slot*$100
; CAUTION: These are padding bytes entered manually, add or remove
; to match if changing code. Firmware must be 256 bytes
.byte 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
.byte 0,0 ;0000 blocks = check status
.byte 3 ;bit 0=read 1=status
.byte entry&$00FF ;low byte of entry

Firmware/Firmware.bin Normal file

Binary file not shown.

Firmware/Warning.asm Normal file
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@ -0,0 +1 @@
.byte "Do not overwrite any of blocks after this point as it is used for the firmware. There are 7 copies of the 256 byte firmware, one for each slot due to 6502 code being non-relocatable. Have fun and feel free to improve on the hardware / sofware. --- Terence"

Firmware/assemble.sh Executable file
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@ -0,0 +1,10 @@
ca65 Warning.asm -o warning.o
ca65 Firmware.asm -D SLOT1 -o slot1.o
ca65 Firmware.asm -D SLOT2 -o slot2.o
ca65 Firmware.asm -D SLOT3 -o slot3.o
ca65 Firmware.asm -D SLOT4 -o slot4.o
ca65 Firmware.asm -D SLOT5 -o slot5.o
ca65 Firmware.asm -D SLOT6 -o slot6.o
ca65 Firmware.asm -D SLOT7 -o slot7.o
ld65 -t none warning.o slot1.o slot2.o slot3.o slot4.o slot5.o slot6.o slot7.o -o Firmware.bin