mirror of
https://github.com/RevCurtisP/C02.git
synced 2024-11-24 15:31:17 +00:00
243 lines
9.3 KiB
Plaintext
243 lines
9.3 KiB
Plaintext
|
; c02 Program Initialization Code for Unexpanded VIC-20
|
||
|
|
|
||
|
|
;PETSCII Control Codes
|
||
|
|
WHT EQU $05 ;White
|
||
|
|
CR EQU $0D ;Carriage Return
|
||
|
|
LWRCS EQU $0E ;Switch to Lower Case
|
||
|
|
LF EQU $11 ;Cursor Down (Line Feed)
|
||
|
|
RVSON EQU $12 ;Reverse On
|
||
|
|
HOME EQU $13 ;Cursor Home
|
||
|
|
DEL EQU $14 ;Delete
|
||
|
|
RED EQU $1C ;Red
|
||
|
|
HT EQU $1D ;Cursor Right (Horizontal Tab)
|
||
|
|
GRN EQU $1E ;Green
|
||
|
|
BLU EQU $1F ;Blue
|
||
|
|
UPRCS EQU $8E ;Switch to Upper Case
|
||
|
|
BLK EQU $90 ;Black
|
||
|
|
VT EQU $91 ;Cursor Up (Vertical Tab)
|
||
|
|
RVSOFF EQU $92 ;Reverse Off
|
||
|
|
CLR EQU $93 ;Clear Screen
|
||
|
|
INST EQU $94 ;Insert
|
||
|
|
PUR EQU $9C ;Purple
|
||
|
|
BS EQU $9D ;Cursor Left (Backspace)
|
||
|
|
YEL EQU $9E ;Yellow
|
||
|
|
CYN EQU $9F ;Cyan
|
||
|
|
|
||
|
|
;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
|
||
|
|
|
||
|
|
;Basic and Screen RAM
|
||
|
|
bas3k EQU $0400 ;Basic Start (3K Expansion Area)
|
||
|
|
basunx EQU $1000 ;Basic Start (Unexpanded)/Video Screen
|
||
|
|
bas8k EQU $1200 ;Basic Start (3K Expansion Area)
|
||
|
|
vicscx EQU $1000 ;Video Screen Memory Area (8K+ Expansion)
|
||
|
|
vicscu EQU $1E00 ;Video Screen Memory Area (Unexpanded)
|
||
|
|
exblk1 EQU $2000 ;8K Expansion RAM/ROM Block 1
|
||
|
|
exblk2 EQU $4000 ;8K Expansion RAM/ROM Block 2
|
||
|
|
exblk3 EQU $6000 ;8K Expansion RAM/ROM Block 3
|
||
|
|
|
||
|
|
chrrom EQU $8000 ;Character Generator ROM
|
||
|
|
|
||
|
|
vicclx EQU $9400 ;Color RAM (8K+ Expansion)
|
||
|
|
vicclu EQU $9600 ;Color RAM (Unexpanded)
|
||
|
|
|
||
|
|
;VIC Chip Registers
|
||
|
|
vicsch EQU $9000 ;Interlace Mode + Horizontal Screen Origin
|
||
|
|
vicscv EQU $9001 ;Vertical Screen Origin
|
||
|
|
viccol EQU $9002 ;Screen Memory Location + Number of Video Columns
|
||
|
|
vicrow EQU $9003 ;Raster Value + Number of Video Rows + Character Size
|
||
|
|
vicrst EQU $9004 ;Raster Value
|
||
|
|
vicloc EQU $9005 ;Screen Memory Location + Character Memory Location
|
||
|
|
viclph EQU $9006 ;Light Pen - Horizontal
|
||
|
|
viclpv EQU $9007 ;Light Pen - Vertical
|
||
|
|
vicpd1 EQU $9008 ;Paddle 1
|
||
|
|
vicpd2 EQU $9009 ;Paddle 2
|
||
|
|
vicbsf EQU $900A ;Bass Sound Switch and Frequency
|
||
|
|
vicasf EQU $900B ;Alto Sound Switch and Frequency
|
||
|
|
vicssf EQU $900C ;Soprano Sound Switch and Frequency
|
||
|
|
vicnsf EQU $900D ;Noise Switch and Frequency
|
||
|
|
vicavl EQU $900E ;Auxillary Color + Sound Volume
|
||
|
|
vicclr EQU $900F ;Screen Color + Reverse Mode + Border Color
|
||
|
|
|
||
|
|
;VIA #1 (NMI)
|
||
|
|
v1orb EQU $9110 ;Port B - User Port
|
||
|
|
v1ora EQU $9111 ;Port A
|
||
|
|
v1ddrb EQU $9112 ;Data Direction Register B
|
||
|
|
v1ddra EQU $9113 ;Data Direction Register A
|
||
|
|
v1t1l EQU $9114 ;Timer #1 Low
|
||
|
|
v1t1h EQU $9115 ;Timer #1 High
|
||
|
|
v1lt1l EQU $9116 ;Load Timer #1 Low
|
||
|
|
v1lt1h EQU $9117 ;Load Timer #1 High
|
||
|
|
v1t2l EQU $9118 ;Timer #1 Low
|
||
|
|
v1t2h EQU $9119 ;Timer #1 High
|
||
|
|
v1sr EQU $911A ;Shift Register
|
||
|
|
v1acr EQU $911B ;Auxillary Control Register
|
||
|
|
v1pcr EQU $911C ;Peripheral Control Register
|
||
|
|
v1ifr EQU $911D ;Interrupt Flag Register
|
||
|
|
v1ier EQU $911E ;Interrupt Enable Register
|
||
|
|
v1oran EQU $911F ;Port A (No Handshake)
|
||
|
|
|
||
|
|
;VIA #2 (IRQ)
|
||
|
|
v2orb EQU $9210 ;Port B
|
||
|
|
v2ora EQU $9211 ;Port A
|
||
|
|
v2ddrb EQU $9212 ;Data Direction Register B
|
||
|
|
v2ddra EQU $9213 ;Data Direction Register A
|
||
|
|
v2t1l EQU $9214 ;Timer #1 Low
|
||
|
|
v2t1h EQU $9215 ;Timer #1 High
|
||
|
|
v2lt1l EQU $9216 ;Load Timer #1 Low
|
||
|
|
v2lt1h EQU $9217 ;Load Timer #1 High
|
||
|
|
v2t2l EQU $9218 ;Timer #1 Low
|
||
|
|
v2t2h EQU $9219 ;Timer #1 High
|
||
|
|
v2sr EQU $921A ;Shift Register
|
||
|
|
v2acr EQU $921B ;Auxillary Control Register
|
||
|
|
v2pcr EQU $921C ;Peripheral Control Register
|
||
|
|
v2ifr EQU $921D ;Interrupt Flag Register
|
||
|
|
v2ier EQU $921E ;Interrupt Enable Register
|
||
|
|
v2oran EQU $921F ;Port A (No Handshake)
|
||
|
|
|
||
|
|
exprom EQU $8000 ;Cartridge Expansion ROM
|
||
|
|
|
||
|
|
|
||
|
|
;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 $1001 ;Start
|
||
|
|
basic: DC $0C, $10 ; Pointer to Next Line (4109)
|
||
|
|
DC $00, $00 ; Line Number (0)
|
||
|
|
DC $9E ; SYS
|
||
|
|
DC $20 ; ' '
|
||
|
|
DC $34, $31, $31 ,$30 ; "4110"
|
||
|
|
DC $00 ;End of Line Marker
|
||
|
|
DC $00, $00 ;End of Basic Program
|
||
|
|
|
||
|
|
JMP main ;Execute Program
|
||
|
|
|
||
|
|
;Poll Keyboard for Character
|
||
|
|
plkey EQU getin ;Read Character from Keyboard Buffer
|
||
|
|
|
||
|
|
;Read Character from Console
|
||
|
|
|
||
|
|
|
||
|
|
;Wait for Character from Console
|
||
|
|
getkey: 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
|
||
|
|
|