; py65mon program initialization code for c02 programs

;System Specific ASCII Key Mappings
DELKEY  EQU $08     ;Delete/Backspace Key (Delete)
ESCKEY  EQU $1B     ;Escape/Stop Key      (Escape)
RTNKEY  EQU $0D     ;Return/Enter Key     (Carriage Return)

;Memory Mapped I/O 
PUTCON  EQU $F001   ;Write Character to Console
GETCON  EQU $F004   ;Read Character from Console

        ORG $0200   ;Start Directly Above Stack

START:  JMP MAIN    ;Execute Program

;Delete Previous Character
DELCHR: JSR DELCHB  ;Print Backspace
        LDA #$20    ;Load Space into Accumulater
        JSR PUTCHR  ;  and Print it
DELCHB: LDA #$08    ;Load Backspace into Accumulator
        BNE PUTCHR  ;  and Print it

        ;Advance Character to Next line
NEWLIN: LDA #$0D    ;Load C/R into Accumulator
        JSR PUTCHR  ;  and Print it
        LDA #$0A    ;Load L/F into Accumulater
                    ;  and fall into PRCHR
;Print Character to Console
PUTCHR STA PUTCON ;Write Character to Console
        RTS

;Poll Keyboard for Keypress
PLKEY:  LDA GETCON  ;Read Character from Console
        RTS

;Wait for Character from Console
GETCHR: JSR POLKEY  ;Read Character from Console
        BEQ GETCHR  ;  Loop if None Received
        RTS

EXIT:   BRK        ;Return to Monitor