mirror of
https://github.com/RevCurtisP/C02.git
synced 2024-11-25 06:31:25 +00:00
47 lines
1.5 KiB
NASM
47 lines
1.5 KiB
NASM
;Apple 1 program initialization code for c02 programs
|
|
|
|
;Locations used by Operating System
|
|
PROMPT EQU $33 ;ASCII character for INPUT prompt symbol
|
|
LOMEM EQU $4A ;
|
|
HIMEM EQU $4C
|
|
BASIC EQU $67 ;Start of BASIC program
|
|
VARBLS EQU $69 ;End of BASIC program and start of variable space
|
|
ARRAYS EQU $6B ;Start of defined array space
|
|
ARRAYE EQU $6D ;End of defined array space
|
|
STRNGS EQU $6F ;Start of string storag
|
|
|
|
;Locations used by Hi-Res Graphics
|
|
HPLOTX $E0 ;X of last HPLOT
|
|
HPLOTY $E2 ;Y of last HPLOT
|
|
HCOLOR $E4 ;
|
|
HIRES $E6 ;
|
|
SCALE $E7 ;
|
|
SHAPES $E8 ;Shape table start address
|
|
XDRAWS $EA
|
|
CSPEED $F1
|
|
ROTATE $F9
|
|
|
|
TIMEDM EQU $BF90 ;Day/month
|
|
TIMEYR EQU $BF91 ;Year
|
|
TIMEMN EQU $BF92 ;Minute
|
|
TIMEHR EQU $BF93 ;Hour
|
|
|
|
|
|
|
|
EXIT EQU $FF00 ;Monitor Entry Point
|
|
ECHO EQU $FFEF ;Subroutine - Print Character in Accumulator
|
|
PRBYTE EQU $FFDC ;Subroutine - Print Accumulator as Hexadadecimal number
|
|
PRHEX EQU $FFE5 ;Subroutine - Print Low Nybble of Accumulator as Hex Digit
|
|
|
|
ORG $0300 ;Start one page above Monitor input buffer
|
|
|
|
START: LDX #$FF ;Reset stack - the monitor doesn't do this
|
|
TXS ; (probably because of lack of space)
|
|
JMP MAIN ;Execute Program
|
|
|
|
RDKEY: BIT KBDCR ;Check the Keyboard Control Register
|
|
BPL RDKEY ; and loop if key not pressed
|
|
LDA KBD ; Read key into Accumulator
|
|
RTS
|
|
|