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94 lines
3.0 KiB
Plaintext
94 lines
3.0 KiB
Plaintext
; c02 Program Initialization Code for Commander X16
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; Compatible with x16emu Release 34
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;PETSCII Key Mappings
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DELKEY EQU $14 ;Delete/Backspace Key (Delete)
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ESCKEY EQU $03 ;Escape/Stop Key (RUN/STOP)
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RTNKEY EQU $0D ;Return/Enter Key (RETURN)
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; $00-$01 ;Miscellaneous Pointer
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; $02-$21 ;ABI Registers
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; $22-$52 ;Used by Basic graphics commands
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XMBANK EQU $53 ;Extended Memory Bank
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XADRLO EQU $54 ;Ext Memory Address LSB
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XADRHI EQU $55 ;Ext Memory Address MSB
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SRCPTR EQU $56 ;Source Pointer
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DSTPTR EQU $59 ;Destination Pointer
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BLKPTR EQU $5C ;Block Pointer
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STKLO EQU $5E ;Stack Pointer LSB
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STKHI EQU $5F ;Stack Pointer MSB
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BFRLO EQU $60 ;Buffer Pointer LSB
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BFRHI EQU $61 ;Buffer Pointer MSB
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RANDOM EQU $62 ;Random Number Storage
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RDSEED EQU $63 ;Random Seed
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TEMP0 EQU $64 ;Temporary Variable
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TEMP1 EQU $65 ;Temporary Variable
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TEMP2 EQU $66 ;Temporary Variable
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TEMP3 EQU $67 ;Temporary Variable
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SYSBFP EQU $68 ;Position in System Buffer [Free Byte]
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; $69-7F ;Available to User
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; $80-$83 ;Used by Kernal and DOS
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; $A4-$A8 ;Reserved for KERNAL/DOS/BASIC
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; $A9-$FF ;Used by BASIC
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;Other Constants
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SYSBFL EQU 128 ;System Buffer Length
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;Other Variables - User Storage Area
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SYSBFR EQU $0700 ;System Buffer
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BLKBGN EQU $07F4 ;Block Start Address
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BLKEND EQU $07F6 ;Block End Address
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BLKLEN EQU $07F8 ;Block Length
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STKSAV EQU $07FA ;Machine Stack Storage
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STKSLO EQU $07FC ;Stack Start LSB
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STKSHI EQU $07FD ;Stack Start MSB
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STKELO EQU $07FE ;Stack End LSB
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STKEHI EQU $07FF ;Stack End MSB
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;Machine Language Basic Stub - Same as Commodore 64
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ORG $0801 ;Start of Basic Program
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BASIC: DC $0C, $08 ;Pointer to Next Line
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DC $00, $00 ;Line Number (0)
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DC $9E ;SYS
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DC $20 ;' '
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DC $32, $30, $36 ,$32 ;"2062"
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DC $00 ;End of Line Marker
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DC $00, $00 ;End of Basic Program
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START: TSX ;Get Stack Pointer
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STX STKSAV ;and Save for Exit
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SEC ;Set Screen Mode
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LDA #0 ;to 40x30 Text
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JSR $FF5F ;using SCRMOD
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JMP MAIN ;Execute Program
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EXIT: LDX STKSAV ;Retrieve Saved Stack Pointer
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TXS ;and Restore It
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RTS ;Return to BASIC
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;Poll Keyboard for Character
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POLKEY EQU $FFE4 ;Aliased to Kernal GETIN Routine
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;Get Character from Keyboard
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GETKEY EQU POLKEY ;Aliased to POLKEY Routine
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;Wait for Character from Keyboard
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GETCHR: JSR GETKEY ;Poll Keyboard
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BEQ GETCHR ;If No Key, Loop
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RTS
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;Print Character to Console
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PUTCHR EQU $FFD2 ;Aliased to CHROUT Routine
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;Delete Previous Character
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DELCHR: LDA #DELKEY ;Load Delete Character
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JMP PUTCHR ;Print and Return
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;Advance Character to Next line
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NEWLIN: LDA #RTNKEY ;Load Return Character
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JMP PUTCHR ;Print and Return
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INCLUDE "prbyte.a02" ;PRBYTE and PRHEX routine
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INCLUDE "putstr.a02" ;PUTSTR routine
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