;
;	SUM INTEGERS FROM MEMORY USING DO-WHILE LOOP
;
;	REGISTER C IS THE SUM
;
	ORG	0x0000		;PROGRAM START ADDRESS
;
COUNT	EQU	8
;
;	PROGRAM SEGMENT BEGINS
;
	LXI	H,D_TBLB	;START OF DATA LIST->HL
	MVI	B,COUNT		;COUNT OF ITEMS IN LIST>B
	MVI	C,0		;0->SUM
;
AGAIN:	MOV	A,C		;SUM+DATA VALUE->SUM
	ADD	M
	MOV	E,A		;SUM->E (TEMPORARY STORAGE)
	MOV	A,C		;IF ADDENDS HAVE DIFFERENT SIGNS THEN CONTINUE
	XRA	M		
	JM	CONT0
	MOV	A,E		;IF ADDENDS HAVE SAME SIGN, DOES THE NEW SUM 
				;HAVE A DIFFERENT SIGN?
	XRA	C
	JM	ERROR		;IF SO, JUMP ERROR
CONT0:	MOV	C,E		;SUM->C
	INX	H		;NEXT DATA VALUE
	DCR	B		;IF COUNT!=0 THEN JUMP AGAIN
	JNZ	AGAIN
;
DONE:	MOV	A,C		;RETRIEVE SUM
	OUT	0xFF		;DISPLAY IN DATA LEDS
	HLT			;HALT
;
ERROR:	SUB	A		;0->A
	OUT	0xFF		;DISPLAY IN DATA LEDS
	HLT			;HALT
;
;	PROGRAM SEGMENT ENDS
;
;	DATA SEGMENT BEGINS
;
D_TBLB:	DB	3,12,32,14,13,38,0,-5
;
;	DATA SEGMENT ENDS
;