; PROGRAM TO COMPARE TWO 8-BIT SIGNED OPERANDS.
; ENTRY:	(A) = OPERAND 1.
;			(B) = OPERAND 2.
;			CALL CMPARE			; CALL SERVICE ROUTINE (SR).
;			(RET FOR A < B) 	; PUT JP < HERE.
;			(RET FOR A = B)		; PUT JP = HERE.
;			(RET FOR A > B)		; PUT JP > HERE.
; EXIT:		(A) UNCHANGED.
;			(B) UNCHANGED.
;			(HL) DESTROYED.
;
.ORG 0000h					; CHANGE ON REASSEMBLY.
			LD	SP,	80h		; THESE LINES ADDED TO TEST THE PROGRAM.
			LD	HL,	20h		; "
			PUSH	HL		; "
			LD	DE,	30h		; "
			LD	A,	10h		; "
			LD	B,	11h		; "
			
CMPARE:		POP HL			; GET RET ADDRESS.
			PUSH DE			; SAVE DE.
			LD	DE,	3		; ADDRESS INCREMENT.
			CP	B			; COMPARE A:B.
			JP	Z,	EQUAL	; GO IF EQUAL.
			PUSH AF			; SAVE FLAGS.
			XOR B			; TEST SIGN BITS.
			RLA				; XOR TO CARRY FLAG.
			JP	C,	DIFFER	; GO IF DIFFERENT SIGNS.
			POP AF			; RESTORE FLAGS.
			JP	C,	LESST	; GO IF A < B.
GREATR:		ADD	HL,	DE		; BUMP RET BY 3.
EQUAL:		ADD HL,	DE		; BUMP RET BY 3.
LESST:		POP	DE			; RESTORE DE.
			JP	(HL)		; RET TO 0,3,6.
DIFFER:		POP	AF			; RESTORE FLAGS.
			JP	C,	GREATR	; GO IF A > B.
			JP	LESST		; A < B.
		HALT
					
.END