Main		LDS	#$4000 	
		LDAA	#$FF		 
		STAA	DDRB		
		LDAA	#$00	
		STAA	DDRA		
BACK		SWI			
		BRA BACK	
SWI_ISR	LDAA	PORTA
		STAA	PORTB
		RTI
		ORG   $FFF6	
		DC.W  SWI_ISR	
		ORG   $FFFE	
		DC.W  Main