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C02/include/vic8k.a02
Curtis F Kaylor 70f03c4db5 Added standard library files include/*
2018-01-28 13:30:49 -05:00

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; c02 Program Initialization Code for Vic-20 with at 8K Expansion
;System Specific ASCII Key Mappings
DELKEY EQU $7F ;Delete/Backspace Key (Delete)
ESCKEY EQU $03 ;Escape/Stop Key (RUN/STOP)
RTNKEY EQU $0D ;Return/Enter Key (RETURN)
;Zero Page Locations
usradd EQU $01 ;Address of USR Routine
linnum EQU $14 ;Integer Line Number Value
txttab EQU $2B ;Pointer to Start of BASIC Program Text
vartab EQU $2D ;Pointer to Start of BASIC Variable Storage Area
arytab EQU $2F ;Pointer to Start of BASIC Array Storage Area
strend EQU $31 ;Pointer to Start of Free RAM
fretop EQU $33 ;Pointer to Bottom of String Text Storage Area
memsiz EQU $37 ;Pointer to Highest Address Used by BASIC
inpptr EQU $43 ;Pointer to Source of GET, READ, or INPUT Information
facexp EQU $61 ;Floating Point Accumulator #1: Exponent
facho EQU $62 ;Floating Point Accumulator #1: Mantissa
facsgn EQU $66 ;Floating Point Accumulator #1: Sign
fac2 EQU $69 ;Floating Point Accumulator #2
argexp EQU $69 ;Floating Point Accumulator #2: Exponent
argho EQU $6E ;Floating Point Accumulator #2: Mantissa
argsgn EQU $6F ;Floating Point Accumulator #2: Sign
chrget EQU $73 ;Subroutine: Get Next BASIC Text Character
chrgot EQU $79 ;Entry Point: Get Current BASIC Text Character
txtptr EQU $7A ;Pointer to Current BASIC Text Character
pointb EQU $7C ;Entry Point: Test Character in Accumulator
exit EQU $8A ;RTS at end of CHRGET, CHRGOT, and POINTB Routines
status EQU $90 ;Kernal I/O Status Word
ldtnd EQU $98 ;Number of Open I/O Files, Index to End of File Tables
dfltn EQU $99 ;Default Input Device (Set to 0 for Keyboard)
dflto EQU $9A ;Default Output (CMD) Device (Set to 3 for Screen)
time EQU $A0 ;Software Jiffy Clock
tape1 EQU $B2 ;Pointer: Start of Tape Buffer
fnlen EQU $B7 ;Length of Current Filename
la EQU $B8 ;Current Logical File Number
sa EQU $B9 ;Current Secondary Address
fa EQU $BA ;Current Device Number
fnadr EQU $BB ;Pointer: Current Filename
lste EQU $C5 ;Matrix Coordinate of Last Key Pressed
ndx EQU $C6 ;Number of Characters in Keyboard Buffer
rvs EQU $C7 ;Flag: Print Reverse Characters
sfdx EQU $CB ;Matrix Coordinate of Current Key Pressed
pnt EQU $D1 ;Pointer to Address of Current Screen Line
pntr EQU $D3 ;Cursor Column on Current Line
lnmx EQU $D5 ;Maximum Length of Physical Screen Line
tblx EQU $D6 ;Current Cursor Physical Line Number
insrt EQU $D8 ;Insert Mode (Number of Inserts)
ldtb1 EQU $D9 ;Screen Line Link Table
pntc EQU $F3 ;Pointer to Address of Current Screen Color RAM Location
usrzp1 EQU $FB ;Free Byte for User Programs
usrzp2 EQU $FC ;Free Byte for User Programs
usrzp3 EQU $FD ;Free Byte for User Programs
usrzp4 EQU $FE ;Free Byte for User Programs
;Basic and Kernal Working Storage
buf EQU $0200 ;BASIC Line Editor Input Buffer
lat EQU $0259 ;Kernal Table of Active Logical File Numbers
fat EQU $0263 ;Kernal Table of Device Numbers for Each Logical File
sat EQU $026D ;Kernal Table of Secondary Addressed for Each Logical File
keyd EQU $0277 ;Keyboard Buffer (Queue)
memstr EQU $0281 ;Pointer: Operating System Start of Memory
memsiz EQU $0283 ;Pointer: Operating System End of Memory
color EQU $0286 ;Current Foreground Color Text
hibase EQU $0288 ;Top Page of Screen Memory
xmax EQU $0289 ;Maximum Keyboard Buffer Size
rptflg EQU $028A ;Flag: Which Key Will Repeat?
kount EQU $028B ;Counter for Timing Delay Between Key Repeats
shflag EQU $028D ;Flag: SHIFT/CTRL/Logo Keypress
mode EQU $0291 ;Flag: Change Character Sets with SHIFT/Logo Keypress
user0 EQU $0310 ;Free Byte for User Programs
user1 EQU $0311 ;Free Byte for User Programs
user2 EQU $0312 ;Free Byte for User Programs
user3 EQU $0313 ;Free Byte for User Programs
user4 EQU $0334 ;Free Byte for User Programs
user5 EQU $0335 ;Free Byte for User Programs
user6 EQU $0336 ;Free Byte for User Programs
user7 EQU $0337 ;Free Byte for User Programs
user8 EQU $0338 ;Free Byte for User Programs
user9 EQU $0339 ;Free Byte for User Programs
user10 EQU $033A ;Free Byte for User Programs
user11 EQU $033B ;Free Byte for User Programs
tbffr EQU $033C ;Cassette I/O Buffer
user12 EQU $03FC ;Free Byte for User Programs
user13 EQU $03FD ;Free Byte for User Programs
user14 EQU $03FE ;Free Byte for User Programs
user15 EQU $03FF ;Free Byte for User Programs
;Video RAM and ROM
vicscn EQU $1000 ;Video Screen Memory Area (Unexpanded)
chrrom EQU $8000 ;Character Generator ROM
vicclr EQU $9400 ;Color RAM (Unexpanded)
;Kernal Routines
chrin EQU $FFCF ;Input Character to Channel
chrout EQU $FFD2 ;Output Character to Channel
getin EQU $FFE4 ;Read Character from Keyboard Buffer
;Machine Language Basic Stub
ORG $1201 ;Start
basic: DC $0C, $12 ; Pointer to Next Line (4108)
DC $00, $00 ; Line Number (0)
DC $9E ; SYS
DC $20 ; ' '
DC $34, $36, $32 ,$32 ; "4622"
DC $00 ;End of Line Marker
DC $00, $00 ;End of Basic Program
start: TSX ;Get Stack Pointer
STX user15 ;and Save for Exit
JMP main ;Execute Program
exit: LDX user15 ;Retrieve Saved Stack Pointer
TXS ;and Restore It
RTS ;Return to BASIC
;Poll Keyboard for Character
plkey EQU getin ;Read Character from Keyboard Buffer
;Get Character from Keyboard
getkey:
;Wait for Character from Keyboard
rdkey: JSR plkey ;Poll Keyboard
BEQ getkey ;If No Key, Loop
RTS
;Delete Previous Character
delchr: RTS
;Advance Character to Next line
newlin: LDA #$0D ;Load C/R into Accumulator
;Print Character to Console
prchr EQU chrout ;
;Print Byte as Two-Digit Hex Number to Console
prbyte: PHA ;Save Accumulater
LSR ;Shift Hi Nybble to Low Nybble
LSR
LSR
LSR
JSR prhex ; and Print it
PLA ;Restore Accumulator
; and fall into prhex
;Print Low Nybble as Hex Digit to Console
prhex: AND #$0F ;Strip High Nybble
CMP #$0A ;If Low Nybble >= 10
BCC prhexc ;
ADC #$06 ; Convert ':' to 'A'...
prhexc: ADC #$30 ;Convert to ASCII Character
JMP prchr ;Print Hex Digit and Return
exit: RTS ;Return to Monitor
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