; Conteo Descendente Con Leds (FFH-00H)
; Gilberto Stankiewicz
; http://www.stan.com.mx
; Abril 2008
; 6502 Macroassambler & Simulator
; http://home.pacbell.net/michal_k/
;
; Puerto         A       B
; Configuracion  $9003   $9002
; Valor          $9001   $9000
;
	.ORG $0400
	LDA #$FF     ; configurar puerto
	STA $9003    ; configurar puerto
	LDA #$FF     ; valor de salida del puerto
	STA $9001    ; valor de salida del puerto
NEXT:	JSR DELAY    ; delay
	DEC $9001    ; $9001 <- $9001 - 1
	JMP NEXT
	
DELAY:	LDX #$04
LOOPX:	LDY #$FF
LOOPY:	DEY
	BNE LOOPY
	DEX 
	BNE LOOPX
	RTS