ca65 V2.18 - N/A Main file : Shell.asm Current file: Shell.asm 000000r 1 ; Copyright Terence J. Boldt (c)2021-2022 000000r 1 ; Use of this source code is governed by an MIT 000000r 1 ; license that can be found in the LICENSE file. 000000r 1 000000r 1 ; This file contains the source for the SHELL 000000r 1 ; application that runs on the Apple II to talk 000000r 1 ; to the Raspberry Pi 000000r 1 000000r 1 ;ProDOS Zero Page 000000r 1 Command = $42 ;ProDOS Command 000000r 1 Unit = $43 ;ProDOS unit (SDDD0000) 000000r 1 BufferLo = $44 000000r 1 BufferHi = $45 000000r 1 BlockLo = $46 000000r 1 BlockHi = $47 000000r 1 000000r 1 ; ProDOS Error Codes 000000r 1 IOError = $27 000000r 1 NoDevice = $28 000000r 1 WriteProtect = $2B 000000r 1 000000r 1 InputByte = $c08e 000000r 1 OutputByte = $c08d 000000r 1 InputFlags = $c08b 000000r 1 OutputFlags = $c087 000000r 1 000000r 1 ResetCommand = $00 000000r 1 ReadBlockCommand = $01 000000r 1 WriteBlockCommand = $02 000000r 1 GetTimeCommand = $03 000000r 1 ChangeDriveCommand = $04 000000r 1 ExecCommand = $05 000000r 1 LoadFileCommand = $06 000000r 1 SaveFileCommand = $07 000000r 1 MenuCommand = $08 000000r 1 ShellCommand = $09 000000r 1 000000r 1 InputString = $fd6a 000000r 1 StringBuffer = $0200 000000r 1 PrintChar = $fded 000000r 1 Keyboard = $c000 000000r 1 ClearKeyboard = $c010 000000r 1 Home = $fc58 000000r 1 Wait = $fca8 000000r 1 PromptChar = $33 000000r 1 Read80Col = $c01f 000000r 1 TextPage1 = $c054 000000r 1 TextPage2 = $c055 000000r 1 000000r 1 htab = $24 000000r 1 vtab = $25 000000r 1 BasL = $28 000000r 1 htab80 = $057b 000000r 1 BasCalc = $fbc1 000000r 1 000000r 1 LastChar = $06 000000r 1 SlotL = $fe 000000r 1 SlotH = $ff 000000r 1 ESC = $9b 000000r 1 000000r 1 .org $2000 002000 1 A2 07 ldx #$07 ; start at slot 7 002002 1 DetectSlot: 002002 1 A0 00 ldy #$00 002004 1 A9 FC lda #$fc 002006 1 85 FE sta SlotL 002008 1 8A txa 002009 1 09 C0 ora #$c0 00200B 1 85 FF sta SlotH 00200D 1 B1 FE lda (SlotL),y 00200F 1 D0 1C bne nextSlot 002011 1 C8 iny 002012 1 B1 FE lda (SlotL),y 002014 1 D0 17 bne nextSlot 002016 1 C8 iny 002017 1 B1 FE lda (SlotL),y 002019 1 C9 17 cmp #$17 00201B 1 D0 10 bne nextSlot 00201D 1 C8 iny 00201E 1 B1 FE lda (SlotL),y 002020 1 C9 14 cmp #$14 002022 1 D0 09 bne nextSlot 002024 1 8A txa 002025 1 0A asl 002026 1 0A asl 002027 1 0A asl 002028 1 0A asl 002029 1 AA tax 00202A 1 18 clc 00202B 1 90 04 bcc Start 00202D 1 nextSlot: 00202D 1 CA dex 00202E 1 D0 D2 bne DetectSlot 002030 1 60 rts 002031 1 Start: 002031 1 A9 8D lda #$8d 002033 1 20 00 C3 jsr $c300 ; force 80 columns 002036 1 A5 06 lda LastChar 002038 1 48 pha 002039 1 2C 10 C0 bit ClearKeyboard 00203C 1 A9 00 lda #ResetCommand 00203E 1 20 D7 20 jsr SendByte 002041 1 A9 09 lda #ShellCommand 002043 1 20 D7 20 jsr SendByte 002046 1 20 52 20 jsr DumpOutput 002049 1 A9 00 lda #ResetCommand 00204B 1 20 D7 20 jsr SendByte 00204E 1 68 pla 00204F 1 85 06 sta LastChar 002051 1 60 rts 002052 1 002052 1 DumpOutput: 002052 1 20 F5 20 jsr GetByte 002055 1 B0 2A bcs checkInput 002057 1 C9 00 cmp #$00 002059 1 F0 39 beq endOutput 00205B 1 48 pha 00205C 1 20 54 21 jsr ClearCursor 00205F 1 68 pla 002060 1 C9 48 cmp #'H' 002062 1 F0 3A beq setColumn 002064 1 C9 56 cmp #'V' 002066 1 F0 44 beq setRow 002068 1 C9 43 cmp #'C' 00206A 1 F0 29 beq clearScreen 00206C 1 C9 54 cmp #'T' 00206E 1 F0 4A beq setTop 002070 1 C9 42 cmp #'B' 002072 1 F0 4E beq setBottom 002074 1 C9 55 cmp #'U' 002076 1 F0 52 beq moveUp 002078 1 20 ED FD jsr PrintChar 00207B 1 20 23 21 jsr SetCursor 00207E 1 4C 52 20 jmp DumpOutput 002081 1 checkInput: 002081 1 2C 00 C0 bit Keyboard ;check for keypress 002084 1 10 CC bpl DumpOutput ;keep dumping output if no keypress 002086 1 AD 00 C0 lda Keyboard ;send keypress to RPi 002089 1 29 7F and #$7f 00208B 1 20 D7 20 jsr SendByte 00208E 1 2C 10 C0 bit ClearKeyboard 002091 1 4C 52 20 jmp DumpOutput 002094 1 endOutput: 002094 1 60 rts 002095 1 clearScreen: 002095 1 20 58 FC jsr Home 002098 1 20 23 21 jsr SetCursor 00209B 1 4C 52 20 jmp DumpOutput 00209E 1 setColumn: 00209E 1 20 F5 20 jsr GetByte 0020A1 1 85 24 sta htab 0020A3 1 8D 7B 05 sta htab80 0020A6 1 20 23 21 jsr SetCursor 0020A9 1 4C 52 20 jmp DumpOutput 0020AC 1 setRow: 0020AC 1 20 F5 20 jsr GetByte 0020AF 1 85 25 sta vtab 0020B1 1 20 C1 FB jsr BasCalc 0020B4 1 20 23 21 jsr SetCursor 0020B7 1 4C 52 20 jmp DumpOutput 0020BA 1 setTop: 0020BA 1 20 F5 20 jsr GetByte 0020BD 1 85 22 sta $22 0020BF 1 4C 52 20 jmp DumpOutput 0020C2 1 setBottom: 0020C2 1 20 F5 20 jsr GetByte 0020C5 1 85 23 sta $23 0020C7 1 4C 52 20 jmp DumpOutput 0020CA 1 moveUp: 0020CA 1 C6 25 dec vtab 0020CC 1 A5 25 lda vtab 0020CE 1 20 C1 FB jsr BasCalc 0020D1 1 20 23 21 jsr SetCursor 0020D4 1 4C 52 20 jmp DumpOutput 0020D7 1 0020D7 1 SendByte: 0020D7 1 48 pha 0020D8 1 waitWrite: 0020D8 1 BD 8B C0 lda InputFlags,x 0020DB 1 2A rol 0020DC 1 2A rol 0020DD 1 B0 F9 bcs waitWrite 0020DF 1 68 pla 0020E0 1 9D 8D C0 sta OutputByte,x 0020E3 1 A9 1E lda #$1e ; set bit 0 low to indicate write started 0020E5 1 9D 87 C0 sta OutputFlags,x 0020E8 1 finishWrite: 0020E8 1 BD 8B C0 lda InputFlags,x 0020EB 1 2A rol 0020EC 1 2A rol 0020ED 1 90 F9 bcc finishWrite 0020EF 1 A9 1F lda #$1f 0020F1 1 9D 87 C0 sta OutputFlags,x 0020F4 1 60 rts 0020F5 1 0020F5 1 GetByte: 0020F5 1 2C 00 C0 bit Keyboard ; skip byte read if key pressed 0020F8 1 90 10 bcc keyPressed 0020FA 1 A9 1D lda #$1d ;set read flag low 0020FC 1 9D 87 C0 sta OutputFlags,x 0020FF 1 waitRead: 0020FF 1 BD 8B C0 lda InputFlags,x 002102 1 2A rol 002103 1 90 0C bcc readByte 002105 1 2C 00 C0 bit Keyboard ;keypress will abort waiting to read 002108 1 10 F5 bpl waitRead 00210A 1 keyPressed: 00210A 1 A9 1F lda #$1f ;set all flags high and exit 00210C 1 9D 87 C0 sta OutputFlags,x 00210F 1 38 sec ;failure 002110 1 60 rts 002111 1 readByte: 002111 1 BD 8E C0 lda InputByte,x 002114 1 48 pha 002115 1 A9 1F lda #$1f ;set all flags high 002117 1 9D 87 C0 sta OutputFlags,x 00211A 1 finishRead: 00211A 1 BD 8B C0 lda InputFlags,x 00211D 1 2A rol 00211E 1 90 FA bcc finishRead 002120 1 68 pla 002121 1 18 clc ;success 002122 1 end: 002122 1 60 rts 002123 1 002123 1 SetCursor: 002123 1 AD 7B 05 lda htab80 ;get horizontal location / 2 002126 1 4A lsr 002127 1 A8 tay 002128 1 AD 55 C0 lda TextPage2 00212B 1 90 03 bcc setChar 00212D 1 AD 54 C0 lda TextPage1 002130 1 setChar: 002130 1 B1 28 lda (BasL),y 002132 1 85 06 sta LastChar ; save so ClearCursor will pick it up 002134 1 C9 E0 cmp #$e0 002136 1 10 0C bpl lowerCase 002138 1 C9 C0 cmp #$c0 00213A 1 10 0D bpl upperCase 00213C 1 C9 A0 cmp #$a0 00213E 1 10 04 bpl symbol 002140 1 C9 80 cmp #$80 002142 1 10 0A bpl noop 002144 1 symbol: 002144 1 lowerCase: 002144 1 invert: 002144 1 49 80 eor #$80 002146 1 4C 4E 21 jmp storeChar 002149 1 upperCase: 002149 1 29 1F and #$1f 00214B 1 4C 4E 21 jmp storeChar 00214E 1 noop: 00214E 1 storeChar: 00214E 1 91 28 sta (BasL),y 002150 1 AD 54 C0 lda TextPage1 002153 1 60 rts 002154 1 002154 1 ClearCursor: 002154 1 AD 7B 05 lda htab80 ;get horizontal location / 2 002157 1 4A lsr 002158 1 A8 tay 002159 1 AD 55 C0 lda TextPage2 00215C 1 90 03 bcc restoreChar 00215E 1 AD 54 C0 lda TextPage1 002161 1 restoreChar: 002161 1 A5 06 lda LastChar 002163 1 91 28 sta (BasL),y 002165 1 AD 54 C0 lda TextPage1 002168 1 60 rts 002168 1