BCLR	DDRB,%00000100		
	LDAA	#$FF		
	STAA  DDRA				
AGAIN	BRSET	PORTB,%00000100,OVER	
	LDAA	#'N'
	STAA	PORTA				
	BRA	AGAIN
OVER  LDAA	#'Y'
	STAA	PORTA				
	BRA	AGAIN