2020-04-27 15:50:22 +00:00
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;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 $0A ;Return/Enter Key (Line Feed)
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;Zero Page Locations
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SRCPTR EQU $30 ;Source String Pointer (stdio.a02)
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SRCLO EQU $30
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SRCHI EQU $31
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DSTPTR EQU $32 ;Destination String Pointer (string.a02)
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DSTLO EQU $32
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DSTHI EQU $33
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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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BLKLO EQU $36
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BLKHI EQU $37
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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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BLKSLO EQU $46 ;Block Start Address
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BLKSHI EQU $47
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BLKELO EQU $48 ;Block End Address
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BLKEHI EQU $49
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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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2020-10-11 18:45:01 +00:00
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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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2020-04-27 15:50:22 +00:00
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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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2020-10-11 18:45:01 +00:00
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ORG $0400 ;START at RAM midpoint
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2020-04-27 15:50:22 +00:00
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START: JMP MAIN ;Execute Program
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;Read Character from Console
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2020-04-27 16:53:59 +00:00
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GETKEY EQU $FFE0 ;Emulator CHRIN Routine
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2020-04-27 15:50:22 +00:00
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;Poll Character from Keyboard
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POLKEY: BRK ;Exit Emulator
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;Wait for Character from Console
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GETCHR: JSR GETKEY ;Read Character from STDIN
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CMP #$FF ;If EOF
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BNE GETCHX
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LDA #ESCKEY ; Set to Escape Character
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GETCHX: ORA 0 ;Set Zero Flag
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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 Accumulater
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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 #RTNKEY ;Load Line Feed into Accumulater
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JMP PUTCHR ; and Print it
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;Print Character to Console
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2020-04-27 16:53:59 +00:00
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PUTCHR EQU $FFE3 ;Emulator CHROUT Routine
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2020-04-27 15:50:22 +00:00
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2020-04-27 16:53:59 +00:00
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EXIT EQU $FFEC ;Emulator SHUTDN Routine
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2020-04-27 15:50:22 +00:00
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2020-10-11 18:45:01 +00:00
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FSCMD EQU $FFE6 ;run6502 File System Command Routine
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2020-04-27 15:50:22 +00:00
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INCLUDE "../include/prbyte.a02" ;PRBYTE and PRHEX routines
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INCLUDE "../include/putstr.a02" ;PUTSTR routine
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