; C'mon, the Compact MONitor ; written by Bruce Clark and placed in the public domain ; ; minor tweaks and porting by Ed Spittles ; ; To the extent possible under law, the owners have waived all ; copyright and related or neighboring rights to this work. ; ; retrieved from http://www.lowkey.comuf.com/cmon.htm ; archived documentation at http://biged.github.io/6502-website-archives/lowkey.comuf.com/cmon.htm ; ; ported to ca65 from dev65 assembler ; /opt/cc65/bin/ca65 --listing -DSINGLESTEP cmon.a65 ; /opt/cc65/bin/ld65 -t none -o cmon.bin cmon.o ; ; define SINGLESTEP to include the single-stepping plugin ; (modified to display registers in AXYS order) ; ; ported to 6502 from 65Org16 ; HEX file upload and OMEN Bravo port ; by Martin Maly .ENGINE bravo .binfrom $e000 .binto $ffff BEGIN EQU $fd00 ACIA_BASE EQU $83fc SDR EQU ACIA_BASE SSR EQU ACIA_BASE+1 SCMD EQU ACIA_BASE+2 SCTL EQU ACIA_BASE+3 SCTL_V EQU 00011111b SCMD_V EQU 00001011b TX_RDY EQU 00010000b RX_RDY EQU 00001000b WIDTH = 8 HEIGHT = 16 ;INPUT = $7F86 ;OUTPUT = $7F83 .MACRO putc JSR MONCOUT .ENDM .MACRO getc JSR MONRDKEY .ENDM .ORG 0 ; cmon zero page usage ADRESS: DS 2 NUMBER: DS 2 AREG: DS 1 PREG: DS 1 SREG: DS 1 XREG: DS 1 YREG: DS 1 STBUF: DS 1 HEXLEN: DS 1 HEX1B: DS 1 HEXADDR: DS 2 .ORG begin INIT: TSX STX SREG PHP PLA STA PREG ;ACIA init LDA #SCTL_V STA SCTL LDA #SCMD_V STA SCMD MON: CLD M1: JSR OUTCR LDA #$2D ;output dash prompt PUTC M2: LDA #0 STA NUMBER+1 STA NUMBER M3: AND #$0F M4: LDY #4 M5: ASL NUMBER ROL NUMBER+1 DEY BNE M5 ORA NUMBER STA NUMBER M6: GETC CMP #$0D BEQ M1 ;branch if cr ; ; Insert additional commands for characters (e.g. control characters) ; outside the range $20 (space) to $7E (tilde) here ; CMP #$20 ;don't output if outside $20-$7E BCC M6 CMP #$7F BCS M6 JSR MONCOUT CMP #$2C BEQ COMMA CMP #$40 BEQ AT CMP #":" BEQ HEXREAD ; ; Insert additional commands for non-letter characters (or case-sensitive ; letters) here ; ;.ifdef SINGLESTEP CMP #$24 ; $ is single step BNE NSSTEP JMP SSTEP ;.endif ; now dealing with letters NSSTEP: EOR #$30 CMP #$0A BCC M4 ;branch if digit ORA #$20 ;convert to upper case SBC #$77 ; ; mapping: ; A-F -> $FFFA-$FFFF ; G-O -> $0000-$0008 ; P-Z -> $FFE9-$FFF3 ; BEQ GO CMP #-6 ; #$FA or #$FFFA BCS M3 ; ; Insert additional commands for (case-insensitive) letters here ; CMP #-15 ; #$F1 or #$FFF1 BNE M6 DUMP: JSR OUTCR TYA PHA CLC ;output address ADC NUMBER PHA LDA #0 ADC NUMBER+1 JSR OUTHEX PLA JSR OUTHSP D1: LDA (NUMBER),Y JSR OUTHSP INY TYA AND #WIDTH-1 BNE D1 PLA TAY D2: LDA (NUMBER),Y AND #$7F CMP #$20 BCC D3 CMP #$7F BCC D4 D3: EOR #$40 D4: PUTC INY TYA AND #WIDTH-1 BNE D2 CPY #WIDTH*HEIGHT BCC DUMP M2J: JMP M2 ; branches out of range for 6502 when putc is 3 bytes COMMA: LDA NUMBER STA (ADRESS),Y INC ADRESS BNE M2J INC ADRESS+1 BCS M2J AT: LDA NUMBER STA ADRESS LDA NUMBER+1 STA ADRESS+1 BCS M2J GO: JSR G1 JMP M2 ; returning after a 'go' G1: JMP (NUMBER) HEXREAD: JSR get1byte STA hexlen JSR get2byterev JSR get1byte CMP #0 BNE hexlast HEXWRITER: JSR get1byte LDX #0 STA (hexaddr,x) INC hexaddr BNE hrns INC hexaddr+1 HRNS: DEC hexlen BNE hexwriter HEXCR: GETC CMP #$0d BNE hexlast LDA #"." JMP m2 HEXLAST: GETC CMP #$0d BNE hexlast LDA #"$" JMP m2 GET1BYTE: GETC BCC get1byte JSR atohex ASL ASL ASL ASL STA hex1b GET1B1: GETC BCC get1b1 JSR atohex CLC ADC hex1b RTS GET2BYTEREV: JSR get1byte STA hexaddr+1 JSR get1byte STA hexaddr RTS ATOHEX: SEC SBC #$30 CMP #$0a BCS atohex2 RTS ATOHEX2: SEC SBC #7 RTS OUTHEX: ;JSR OH1 ; for 16-bit bytes OH1: JSR OH2 OH2: ASL ADC #0 ASL ADC #0 ASL ADC #0 ASL ADC #0 PHA AND #$0F CMP #$0A BCC OH3 ADC #$66 OH3: EOR #$30 PUTC PLA RTS OUTHSP: JSR OUTHEX LDA #$20 OA1: PUTC RTS OUTCR: LDA #$0D PUTC LDA #$0A BNE OA1 ;always SSTEP: LDX #7 STEP1: LDA STEP4,X STA STBUF+1,X DEX BPL STEP1 LDX SREG TXS LDA (ADRESS),Y BEQ STBRK JSR GETLEN TYA PHA STEP2: LDA (ADRESS),Y STA STBUF,Y DEY BPL STEP2 EOR #$20 CMP #1 PLA JSR STADR LDA STBUF CMP #$20 BEQ STJSR CMP #$4C BEQ STJMP CMP #$40 BEQ STRTI CMP #$60 BEQ STRTS CMP #$6C BEQ STJMPI AND #$1F CMP #$10 BNE STEP3 LDA #4 STA STBUF+1 STEP3: LDA PREG PHA LDA AREG LDX XREG LDY YREG PLP JMP STBUF STEP4: NOP NOP JMP STNB JMP STBR STJSR: LDA ADRESS+1 PHA LDA ADRESS PHA ;fall thru STJMP: LDY STBUF+1 LDA STBUF+2 STJMP1: STY ADRESS STJMP2: STA ADRESS+1 JMP STNB1 STJMPI: INY LDA (STBUF+1),Y STA ADRESS INY LDA (STBUF+1),Y JMP STJMP2 STRTI: PLA STA PREG PLA STA ADRESS PLA JMP STJMP2 STRTS: PLA STA ADRESS PLA STA ADRESS+1 LDA #0 JSR STADR JMP STNB1 STBRK: LDA ADRESS+1 PHA LDA ADRESS PHA LDA PREG PHA ORA #$04 ; set i flag AND #$F7 ; clear d flag STA PREG LDY -2 ; $FFFFFFFE LDA -1 ; $FFFFFFFF JMP STJMP1 STNB: PHP STA AREG STX XREG STY YREG PLA STA PREG CLD STNB1: TSX STX SREG STNB2: JSR STOUT JMP M2 STBR: DEC ADRESS+1 LDY #-1 ; #$FFFF LDA (ADRESS),Y BMI STBR1 INC ADRESS+1 STBR1: CLC JSR STADR JMP STNB2 STADR: ADC ADRESS STA ADRESS BCC STADR1 INC ADRESS+1 STADR1: RTS OUTPC: LDA ADRESS+1 JSR OUTHEX LDA ADRESS JMP OUTHSP STOUT: JSR OUTCR JSR OUTPC ; fall thru OUTREG: LDA AREG JSR OUTHSP LDA XREG JSR OUTHSP LDA YREG JSR OUTHSP LDA SREG JSR OUTHSP LDA PREG JSR OUTHSP LDA PREG ;fall thru OUTBIN: SEC ROL OUTB1: PHA LDA #$18 ROL PUTC PLA ASL BNE OUTB1 RTS ; ; 0123456789ABCDEF ; ; 00 22...22.121..33. ; 10 22...22.13...33. ; 20 32..222.121.333. ; 30 22...22.13...33. ; 40 12...22.121.333. ; 50 22...22.13...33. ; 60 12...22.121.333. ; 70 22...22.13...33. ; 80 .2..222.1.1.333. ; 90 22..222.131..3.. ; A0 222.222.121.333. ; B0 22..222.131.333. ; C0 22..222.121.333. ; D0 22...22.13...33. ; E0 22..222.121.333. ; F0 22...22.13...33. ; ; Return instruction length - 1 (note that BRK is considered to be a 2 byte ; instruction and returns 1) ; GETLEN: LDY #1 CMP #$20 ; if opcode = $20, then length = 3 BEQ GETL3 AND #$DF CMP #$40 BEQ GETL1 ; if (opcode & $DF) = $40, then length = 1 AND #$1F CMP #$19 BEQ GETL3 ; if (opcode & $1F) = $19, then length = 3 AND #$0D CMP #$08 BNE GETL2 ; if (opcode & $0D) = $08, then length = 1 GETL1: DEY GETL2: CMP #$0C BCC GETL4 ; if (opcode & $0D) >= $0C, then length = 3 GETL3: INY GETL4: RTS BREAK: STA AREG STX XREG STY YREG PLA STA PREG PLA STA ADRESS PLA STA ADRESS+1 TSX STX SREG CLD JSR STOUT JMP M1 MONCOUT: PHA SERIALOUTWAIT: LDA SSR AND #TX_RDY CMP #TX_RDY BNE SerialOutWait PLA STA SDR RTS MONRDKEY: LDA SSR AND #RX_RDY CMP #RX_RDY BNE NoDataIn LDA SDR SEC ; Carry set if key available RTS NODATAIN: CLC ; Carry clear if no key pressed RTS .include patreon.a65 .ORG $FFFA LNMI: DB 1,2 LRESET: DW init LIRQBRK: DW BREAK LEND: