TEMP   DS.B 1
Entry: LDS	#RAMEnd+1	
	ANDCC	#%10111111
	BSET	DDRB,%00010000	
	BCLR	PORTB,%00010000
HERE	BRA	HERE			
XIRQ_ISR
	LDAA	TEMP			
	EORA	#%00010000	
	STAA	TEMP			
	STAA	PORTB         	
	RTI				
	ORG   $FFF4
	DC.W  XIRQ_ISR	
	ORG   $FFFE
	DC.W  Entry