Apple2-IO-RPi/Apple2/RPi.Command.asm

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2022-01-11 04:00:58 +00:00
; 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.
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XRETURN = $FF58 ;Known RTS instruction.
InputByte = $c08e
OutputByte = $c08d
InputFlags = $c08b
OutputFlags = $c087
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
LastChar = $06
SlotL = $fe
SlotH = $ff
ESC = $9b
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;macro for string with high-bit set
.macro aschi str
.repeat .strlen (str), c
.byte .strat (str, c) | $80
.endrep
.endmacro
.org $2000
ldx #$07 ; start at slot 7
DetectSlot:
ldy #$00
lda #$fc
sta SlotL
txa
ora #$c0
sta SlotH
lda (SlotL),y
bne nextSlot
iny
lda (SlotL),y
bne nextSlot
iny
lda (SlotL),y
cmp #$17
bne nextSlot
iny
lda (SlotL),y
cmp #$14
bne nextSlot
txa
asl
asl
asl
asl
tax
clc
bcc Start
nextSlot:
dex
bne DetectSlot
rts
Start:
stx slotx + $1e01 ;set the slot for the driver
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ldy #$00
PrintString:
lda Text,y
beq copyDriver
ora #$80
jsr PrintChar
iny
bne PrintString
copyDriver:
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ldy #$00
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copyDriverByte:
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lda $2100,y
sta $0300,y
iny
cpy #$e6
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bne copyDriverByte
;
; 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.
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lda #ExecCommand
jsr SendByte
ldy #$00
nextCommandByte:
lda a2help, y
beq finishCommand
jsr SendByte
iny
jmp nextCommandByte
finishCommand:
lda #$00
jsr SendByte
showVersion:
jsr GetByte
cmp #$00
beq FinishDriver
jsr PrintChar
jmp showVersion
FinishDriver:
rts
a2help:
.byte "a2help", $00
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Text:
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aschi "RPI command version: 000E"
.byte $8d
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end:
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.byte $00
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.repeat 255-<end
.byte 0
.endrepeat
.org $0300
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
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;lda #$8d
;sta $02ff
;lda #$fe
STA XLEN ; in CI global XLEN.
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LDA #<XRETURN ;Point XTRNADDR to a known
STA XTRNADDR ; RTS since we'll handle
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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
slotx: ldx #$70 ; set x to slot # in high nibble
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
cmp #$00
beq endOutput
jsr PrintChar
clc
bcc DumpOutput
endOutput:
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clc
jmp (NXTCMD)
HelpCommand:
.byte "a2help",$00
SendByte:
pha
waitWrite:
lda InputFlags,x
rol
rol
bcs waitWrite
pla
sta OutputByte,x
lda #$1e ; set bit 0 low to indicate write started
sta OutputFlags,x
finishWrite:
lda InputFlags,x
rol
rol
bcc finishWrite
lda #$1f
sta OutputFlags,x
rts
GetByte:
lda #$1d ;set read flag low
sta OutputFlags,x
waitRead:
lda InputFlags,x
rol
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bcs waitRead
readByte:
lda InputByte,x
pha
lda #$1f ;set all flags high
sta OutputFlags,x
finishRead:
lda InputFlags,x
rol
bcc finishRead
pla
clc ;success
rts
CMD: aschi "rpi"
CMDLEN = 3 ;Our command length
;
NXTCMD: .byte 0,0 ; STORE THE NEXT EXT CMD'S
; ADDRESS HERE.