LREG 	EQU	$820
GREG 	EQU 	$821
	BCLR	DDRB,%11111111		
	LDAA	#75			
	CMPA  PORTB		
	BEQ	EXIT		
	LDAA	PORTB		
	BLO	LOWER		
	STAA	GREG		
	BRA	EXIT
LOWER	STAA  LREG		
EXIT	.....