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97 lines
2.6 KiB
Plaintext
97 lines
2.6 KiB
Plaintext
;run6502 program initialization code for c02 programs
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;System Specific ASCII Key Mappings
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DELKEY EQU $08 ;Delete/Backspace Key (Backspace)
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ESCKEY EQU $18 ;Escape/Stop Key (Control-X)
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RTNKEY EQU $0D ;Return/Enter Key (Carriage Return)
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;Zero Page Locations
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SRCPTR EQU $30 ;Source String Pointer (stdio.a02)
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DSTPTR EQU $32 ;Destination String Pointer (string.a02)
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BFRPTR EQU $34 ;Work Buffer Pointer
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BFRLO EQU $34
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BFRHI EQU $35
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BLKPTR EQU $36 ;Block Segment Pointer (block.a02)
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STKLO EQU $38 ;Stack Pointer (stack.a02)
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STKHI EQU $39
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RDSEED EQU $3E ;Pseudo-RANDOM Seed
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RANDOM EQU $3F ;Pseudo-RANDOM Number Storage
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TEMP0 EQU $40 ;Temporary Storage
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TEMP1 EQU $41
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TEMP2 EQU $42
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TEMP3 EQU $43
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BLKBGN EQU $46
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BLKEND EQU $48
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BLKLEN EQU $4A ;Block Segment Length
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STKSLO EQU $4C ;Stack Start Address
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STKSHI EQU $4D
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STKELO EQU $4E ;Stack End Address
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STKEHI EQU $4F
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SYSBFP EQU $50 ;Position in System Buffer
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SYSBFL EQU 128 ;System Buffer Size (Max String Size)
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SYSBFR EQU $0200 ;System Buffer
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;Memory Mapped I/O
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_KBHIT EQU $FFF0 ;Is a Key Pressed
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_GETCH EQU $FFF1 ;Read Keyboard (Blocking)
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ORG $0400 ;START at RAM midpoint
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START: JMP MAIN ;Execute Program
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;Read Character from Console
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GETKEY EQU $FFE0 ;Emulator _GETCH Routine
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;Poll Character from Keyboard
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POLKEY: BRK ;Exit Emulator
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;Wait for Character from Console
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GETCHR: JSR GETKEY ;Get Key from Console
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BEQ GETCHR ;If None Pressed, Loop
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RTS
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;Read Character from stdin
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RDCHAR: LDA $FFEA ;Read Character from STDIN
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CMP #$FF ;If EOF
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BNE RDCHAX
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LDA #0 ; Set to ASCII NUL
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RDCHAX ORA #0 ;Set Flags
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RTS
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;Delete Previous Character
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DELCHR: LDA #$08 ;Load Backspace into Accumulator
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JSR PUTCHR ; and Print it
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LDA #$20 ;Load Space into Accumulator
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JSR PUTCHR ; and Print it
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LDA #$08 ;Load Backspace into Accumulator
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JMP PUTCHR ; and Print it
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;Advance Character to Next line
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NEWLIN: LDA #$0D ;Load Carriage Return into Accumulator
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JSR PUTCHR ; and Print it
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LDA #$0A ;Load Line Feed into Accumulator
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JMP PUTCHR ; and Print it
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;Print Character to Console
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PUTCHR EQU $FFE3 ;Emulator CHROUT Routine
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;Write Character to stdout
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PRCHAR: STA $FFEA ;Read Character from STDIN
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RTS
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EXIT EQU $FFEC ;Emulator SHUTDN Routine
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FSCMD EQU $FFE6 ;run6502 File System Command Routine
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INCLUDE "prbyte.a02" ;PRBYTE and PRHEX routines
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INCLUDE "putstr.a02" ;PUTSTR routine
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