mirror of https://github.com/RevCurtisP/C02.git
90 lines
2.9 KiB
Plaintext
90 lines
2.9 KiB
Plaintext
; c02 Program Initialization Code for Commander X16
|
|
; Compatible with x16emu Release 34
|
|
|
|
;PETSCII Key Mappings
|
|
DELKEY EQU $14 ;Delete/Backspace Key (Delete)
|
|
ESCKEY EQU $03 ;Escape/Stop Key (RUN/STOP)
|
|
RTNKEY EQU $0D ;Return/Enter Key (RETURN)
|
|
|
|
; $00-$01 ;Miscellaneous Pointer
|
|
; $02-$21 ;ABI Registers
|
|
; $22-$52 ;Used by Basic graphics commands
|
|
XMBANK EQU $53 ;Extended Memory Bank
|
|
XMADDR EQU $54 ;Ext Memory Address
|
|
SRCPTR EQU $56 ;Source Pointer
|
|
DSTPTR EQU $58 ;Destination Pointer
|
|
BLKPTR EQU $5A ;Block Pointer
|
|
STKPTR EQU $5C ;Stack Pointer
|
|
USRPTR EQU $5E ;User Pointer
|
|
RANDOM EQU $62 ;Random Number Storage
|
|
RDSEED EQU $63 ;Random Seed
|
|
TEMP0 EQU $64 ;Temporary Variables
|
|
TEMP1 EQU $65
|
|
TEMP2 EQU $66
|
|
TEMP3 EQU $67
|
|
TMPPTR EQU $68 ;Temporary Pointer
|
|
SYSBFP EQU $6A ;Position in System Buffr
|
|
; $6B-$6F ;Unused
|
|
; $70-7F ;Free Zero-Page for Applications
|
|
; $80-$83 ;Used by Kernal and DOS
|
|
; $A4-$A8 ;Reserved for KERNAL/DOS/BASIC
|
|
; $A9-$FF ;Used by BASIC
|
|
|
|
;Other Constants
|
|
SYSBFL EQU 128 ;System Buffer Length [Max String Length]
|
|
;Other Variables - User Storage Area
|
|
SYSBFR EQU $0700 ;System Buffer
|
|
; $0781-$07F5 ;Unused
|
|
BLKBGN EQU $07F6 ;Block Start Address
|
|
BLKEND EQU $07F8 ;Block End Address
|
|
BLKLEN EQU $07FA ;Block Length
|
|
STKSAV EQU $07FB ;Machine Stack Storage
|
|
STKBGN EQU $07FC ;Stack Start
|
|
STKEND EQU $07FE ;Stack End
|
|
|
|
;Machine Language Basic Stub - Same as Commodore 64
|
|
ORG $0801 ;Start of Basic Program
|
|
BASIC: DC $0C, $08 ;Pointer to Next Line
|
|
DC $00, $00 ;Line Number (0)
|
|
DC $9E ;SYS
|
|
DC $20 ;' '
|
|
DC $32, $30, $36 ,$32 ;"2062"
|
|
DC $00 ;End of Line Marker
|
|
DC $00, $00 ;End of Basic Program
|
|
|
|
START: TSX ;Get Stack Pointer
|
|
STX STKSAV ;and Save for Exit
|
|
SEC ;Set Screen Mode
|
|
LDA #0 ;to 40x30 Text
|
|
JSR $FF5F ;using SCRMOD
|
|
JMP MAIN ;Execute Program
|
|
|
|
EXIT: LDX STKSAV ;Retrieve Saved Stack Pointer
|
|
TXS ;and Restore It
|
|
RTS ;Return to BASIC
|
|
|
|
;Poll Keyboard for Character
|
|
POLKEY EQU $FFE4 ;Aliased to Kernal GETIN Routine
|
|
|
|
;Get Character from Keyboard
|
|
GETKEY EQU POLKEY ;Aliased to POLKEY Routine
|
|
|
|
;Wait for Character from Keyboard
|
|
GETCHR: JSR GETKEY ;Poll Keyboard
|
|
BEQ GETCHR ;If No Key, Loop
|
|
RTS
|
|
|
|
;Print Character to Console
|
|
PUTCHR EQU $FFD2 ;Aliased to CHROUT Routine
|
|
|
|
;Delete Previous Character
|
|
DELCHR: LDA #DELKEY ;Load Delete Character
|
|
JMP PUTCHR ;Print and Return
|
|
|
|
;Advance Character to Next line
|
|
NEWLIN: LDA #RTNKEY ;Load Return Character
|
|
JMP PUTCHR ;Print and Return
|
|
|
|
INCLUDE "prbyte.a02" ;PRBYTE and PRHEX routine
|
|
INCLUDE "putstr.a02" ;PUTSTR routine
|