org 	$1500	; starting address of the program
	ldd	$1002	; place the lowest two bytes of the minuend in D
	subd	$1006	; subtract the lowest two bytes of the subtrahend
			; from D
	std	$1012	; save the lowest two bytes of the difference
	ldaa	$1001	; put the second-to-most-significant byte of the
			; minuend in A
	sbca	$1005	; subtract the second-to-most-significant byte of the
			; subtrahend and the borrow from A
	staa	$1011	; save the second-to-most-significant byte of the
			; difference
	ldaa	$1000	; put the most significant byte of the minuend in A
	sbca	$1004	; subtract the most significant byte of the subtrahend
			; and the borrow from A
	staa	$1010	; save the most significant byte of the difference
	end