mirror of
https://github.com/tjboldt/Apple2-IO-RPi.git
synced 2024-11-25 21:33:15 +00:00
185 lines
4.3 KiB
NASM
185 lines
4.3 KiB
NASM
; Copyright Terence J. Boldt (c)2021-2022
|
|
; Use of this source code is governed by an MIT
|
|
; license that can be found in the LICENSE file.
|
|
|
|
; This file contains the source for the RPI.COMMAND
|
|
; application that runs on the Apple II and extends
|
|
; ProDOS BASIC.SYSTEM to add the RPI command which
|
|
; allows commands to be executed on the Raspberry Pi
|
|
|
|
.ORG $300
|
|
INBUF = $200 ;GETLN input buffer.
|
|
WAIT = $FCA8 ;Monitor wait routine.
|
|
BELL = $FF3A ;Monitor bell routine.
|
|
EXTRNCMD = $BE06 ;External cmd JMP vector.
|
|
XTRNADDR = $BE50 ;Ext cmd implementation addr.
|
|
XLEN = $BE52 ;length of command string-1.
|
|
XCNUM = $BE53 ;CI cmd no. (ext cmd - 0).
|
|
PBITS = $BE54 ;Command parameter bits.
|
|
XRETURN = $FF58 ;Known RTS instruction.
|
|
InputByte = $c0fe
|
|
OutputByte = $c0fd
|
|
InputFlags = $c0fb
|
|
OutputFlags = $c0f7
|
|
|
|
ReadBlockCommand = $01
|
|
WriteBlockCommand = $02
|
|
GetTimeCommand = $03
|
|
ChangeDriveCommand = $04
|
|
ExecCommand = $05
|
|
LoadFileCommand = $06
|
|
SaveFileCommand = $07
|
|
MenuCommand = $08
|
|
|
|
InputString = $fd67
|
|
PrintChar = $fded
|
|
Keyboard = $c000
|
|
ClearKeyboard = $c010
|
|
Wait = $fca8
|
|
|
|
;
|
|
; FIRST SAVE THE EXTERNAL COMMAND ADDRESS SO YOU WON'T
|
|
; DISCONNECT ANY PREVIOUSLY CONNECTED COMMAND.
|
|
;
|
|
LDA EXTRNCMD+1
|
|
STA NXTCMD
|
|
LDA EXTRNCMD+2
|
|
STA NXTCMD+1
|
|
;
|
|
LDA #<RPI ;Install the address of our
|
|
STA EXTRNCMD+1 ; command handler in the
|
|
LDA #>RPI ; external command JMP
|
|
STA EXTRNCMD+2 ; vector.
|
|
RTS
|
|
;
|
|
RPI: LDX #0 ;Check for our command.
|
|
NXTCHR: LDA INBUF,X ;Get first character.
|
|
ora #$20 ;Make it lower case
|
|
CMP CMD,X ;Does it match?
|
|
BNE NOTOURS ;No, back to CI.
|
|
INX ;Next character
|
|
CPX #CMDLEN ;All characters yet?
|
|
BNE NXTCHR ;No, read next one.
|
|
;
|
|
LDA #CMDLEN-1 ;Our cmd! Put cmd length-1
|
|
;lda #$8d
|
|
;sta $02ff
|
|
;lda #$fe
|
|
STA XLEN ; in CI global XLEN.
|
|
LDA #<XRETURN ;Point XTRNADDR to a known
|
|
STA XTRNADDR ; RTS since we'll handle
|
|
LDA #>XRETURN ; at the time we intercept
|
|
|
|
STA XTRNADDR+1 ; our command.
|
|
LDA #0 ;Mark the cmd number as
|
|
STA XCNUM ; zero (external).
|
|
STA PBITS ;And indicate no parameters
|
|
STA PBITS+1 ; to be parsed.
|
|
lda #$8d
|
|
jsr $fded
|
|
clc
|
|
bcc SendCommand
|
|
;
|
|
NOTOURS: SEC ; ALWAYS SET CARRY IF NOT YOUR
|
|
JMP (NXTCMD) ; CMD AND LET NEXT COMMAND TRY
|
|
; ; TO CLAIM IT.
|
|
|
|
SendCommand:
|
|
bit ClearKeyboard
|
|
lda #$05 ;send command 5 = exec
|
|
jsr SendByte
|
|
ldy #$03 ;skip over "RPI"
|
|
getInput:
|
|
lda $0200,y
|
|
cmp #$8d
|
|
beq sendNullTerminator
|
|
and #$7f
|
|
jsr SendByte
|
|
iny
|
|
bne getInput
|
|
sendNullTerminator:
|
|
lda #$00
|
|
jsr SendByte
|
|
DumpOutput:
|
|
jsr GetByte
|
|
bcs skipOutput
|
|
cmp #$00
|
|
beq endOutput
|
|
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:
|
|
clc
|
|
jmp (NXTCMD)
|
|
|
|
HelpCommand:
|
|
.byte "a2help",$00
|
|
|
|
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
|
|
rts
|
|
|
|
|
|
;macro for string with high-bit set
|
|
.macro aschi str
|
|
.repeat .strlen (str), c
|
|
.byte .strat (str, c) | $80
|
|
.endrep
|
|
.endmacro
|
|
|
|
CMD: aschi "rpi"
|
|
CMDLEN = 3 ;Our command length
|
|
;
|
|
NXTCMD: .byte 0,0 ; STORE THE NEXT EXT CMD'S
|
|
; ADDRESS HERE.
|