apple1js/asm/cell.s

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2020-10-09 02:23:01 +00:00
;
; Apple 1 Cellular Automaton
; https://mathworld.wolfram.com/CellularAutomaton.html
; By Will Scullin
;
ORG $300
ECHO EQU $FFEF
CR EQU $8D
; Load Rule $5A = 90
START LDA #$5A
LDX #0
RULELOOP LSR A
TAY
LDA #$00
ROR A
STA RULES,X
TYA
INX
CPX #$08
BNE RULELOOP
; Print Row
OUT LDA #CR
JSR ECHO
LDX #$00
OUTLOOP LDA CELLS,X
BMI SOLID
LDA #' '
BPL OUT
SOLID LDA #'X'
OUT JSR ECHO
INX
CPX #$27
BCC OUTLOOP
; Update Row
LDA CELLS
ASL A
LDA #$00
ROL A
LDX #$FF
UPDATELOOP INX
TAY
LDA CELLS+1,X
ASL
TYA
ROL A
TAY
LDA RULE,Y
STA CELLS,X
TYA
AND #$03
CPX #$27
BCC UPDATELOOP
BCS OUT
; Workspace
CELLS DB $00,$00,$00,$00,$00,$00,$00,$00,
DB $00,$00,$00,$00,$00,$00,$00,$00,
DB $00,$00,$00,$80,$00,$00,$00,$00,
DB $00,$00,$00,$00,$00,$00,$00,$00,
DB $00,$00,$00,$00,$00,$00,$00,$00
RULE DB $00,$00,$00,$00,$00,$00,$00,$00
000
001