mirror of
https://github.com/tjboldt/Apple2-IO-RPi.git
synced 2024-05-29 00:41:45 +00:00
205 lines
3.1 KiB
NASM
Executable File
205 lines
3.1 KiB
NASM
Executable File
;ProDOS Zero Page
|
|
Command = $42 ;ProDOS Command
|
|
Unit = $43 ;ProDOS unit (SDDD0000)
|
|
BufferLo = $44
|
|
BufferHi = $45
|
|
BlockLo = $46
|
|
BlockHi = $47
|
|
|
|
; ProDOS Error Codes
|
|
IOError = $27
|
|
NoDevice = $28
|
|
WriteProtect = $2B
|
|
|
|
; hard code slot to 7 for now, will make it auto-detect later
|
|
SLOT = 7
|
|
|
|
InputByte = $c08e+SLOT*$10
|
|
OutputByte = $c08d+SLOT*$10
|
|
InputFlags = $c08b+SLOT*$10
|
|
OutputFlags = $c087+SLOT*$10
|
|
|
|
ReadBlockCommand = $01
|
|
WriteBlockCommand = $02
|
|
GetTimeCommand = $03
|
|
ChangeDriveCommand = $04
|
|
ExecCommand = $05
|
|
LoadFileCommand = $06
|
|
SaveFileCommand = $07
|
|
MenuCommand = $08
|
|
|
|
InputString = $fd6a
|
|
StringBuffer = $0200
|
|
PrintChar = $fded
|
|
Keyboard = $c000
|
|
ClearKeyboard = $c010
|
|
Wait = $fca8
|
|
PromptChar = $33
|
|
|
|
ESC = $9b
|
|
|
|
.org $2000
|
|
Start:
|
|
lda PromptChar
|
|
sta OldPromptChar
|
|
lda #'$'|$80
|
|
sta PromptChar
|
|
lda #ExecCommand
|
|
jsr SendByte
|
|
ldx #$00
|
|
sendHelpCommand:
|
|
lda HelpCommand,x
|
|
cmp #$00
|
|
beq sendHelpCommandEnd
|
|
jsr SendByte
|
|
inx
|
|
bpl sendHelpCommand
|
|
sendHelpCommandEnd:
|
|
lda #$00
|
|
jsr SendByte
|
|
bit ClearKeyboard
|
|
jsr DumpOutput
|
|
|
|
Prompt:
|
|
lda #ExecCommand
|
|
jsr SendByte
|
|
ldx #$00
|
|
sendPromptCommand:
|
|
lda PromptCommand,x
|
|
cmp #$00
|
|
beq sendPromptCommandEnd
|
|
jsr SendByte
|
|
inx
|
|
bpl sendPromptCommand
|
|
sendPromptCommandEnd:
|
|
lda #$00
|
|
jsr SendByte
|
|
bit ClearKeyboard
|
|
jsr DumpOutput
|
|
|
|
; get input
|
|
jsr InputString
|
|
; check for "exit"
|
|
lda StringBuffer
|
|
cmp #'e'|$80
|
|
bne Execute
|
|
lda StringBuffer+1
|
|
cmp #'x'|$80
|
|
bne Execute
|
|
lda StringBuffer+2
|
|
cmp #'i'|$80
|
|
bne Execute
|
|
lda StringBuffer+3
|
|
cmp #'t'|$80
|
|
bne Execute
|
|
lda OldPromptChar
|
|
sta PromptChar
|
|
rts
|
|
Execute:
|
|
bit ClearKeyboard
|
|
lda #ExecCommand
|
|
jsr SendByte
|
|
ldy #$00
|
|
sendInput:
|
|
lda $0200,y
|
|
cmp #$8d
|
|
beq sendNullTerminator
|
|
and #$7f
|
|
jsr SendByte
|
|
iny
|
|
bne sendInput
|
|
sendNullTerminator:
|
|
lda #$00
|
|
jsr SendByte
|
|
jsr DumpOutput
|
|
jmp Prompt
|
|
|
|
DumpOutput:
|
|
jsr GetByte
|
|
bcs skipOutput
|
|
cmp #$00
|
|
beq endOutput
|
|
cmp #ESC
|
|
beq escapeSequence
|
|
jsr PrintChar
|
|
skipOutput:
|
|
bit Keyboard ;check for keypress
|
|
bpl DumpOutput ;keep dumping output if no keypress
|
|
lda Keyboard ;send keypress to RPi
|
|
;jsr PrintChar
|
|
and #$7f
|
|
jsr SendByte
|
|
bit ClearKeyboard
|
|
clc
|
|
bcc DumpOutput
|
|
endOutput:
|
|
rts
|
|
escapeSequence:
|
|
jsr ParseEscape
|
|
clc
|
|
bcc DumpOutput
|
|
|
|
ParseEscape:
|
|
jsr GetByte ; expect first byte after ESC to be '['
|
|
cmp #'['|$80
|
|
beq endParse
|
|
checkLetter:
|
|
jsr GetByte ; loop until there is a letter
|
|
cmp #$C1
|
|
bcc checkLetter
|
|
endParse:
|
|
rts
|
|
|
|
SendByte:
|
|
pha
|
|
waitWrite:
|
|
lda InputFlags
|
|
rol
|
|
rol
|
|
bcs waitWrite
|
|
pla
|
|
sta OutputByte
|
|
lda #$1e ; set bit 0 low to indicate write started
|
|
sta OutputFlags
|
|
finishWrite:
|
|
lda InputFlags
|
|
rol
|
|
rol
|
|
bcc finishWrite
|
|
lda #$1f
|
|
sta OutputFlags
|
|
rts
|
|
|
|
GetByte:
|
|
lda #$1d ;set read flag low
|
|
sta OutputFlags
|
|
waitRead:
|
|
lda InputFlags
|
|
rol
|
|
bcc readByte
|
|
bit Keyboard ;keypress will abort waiting to read
|
|
bpl waitRead
|
|
lda #$1f ;set all flags high and exit
|
|
sta OutputFlags
|
|
sec ;failure
|
|
rts
|
|
readByte:
|
|
lda InputByte
|
|
pha
|
|
lda #$1f ;set all flags high
|
|
sta OutputFlags
|
|
finishRead:
|
|
lda InputFlags
|
|
rol
|
|
bcc finishRead
|
|
pla
|
|
clc ;success
|
|
end:
|
|
rts
|
|
|
|
HelpCommand:
|
|
.byte "a2help",$00
|
|
PromptCommand:
|
|
.byte "a2prompt",$00
|
|
OldPromptChar:
|
|
.byte "]" |