TITLE     PROG5-2
   PAGE 60,132
   ;--------------
   MULTIPLY  MACRO  VALUE1, VALUE2, RESULT
             LOCAL BACK
   ;THIS MACRO COMPUTES RESULT = VALUE1 X VALUE2
   ;;BY REPEATED ADDITION
   ;;VALUE1 AND VALUE2 ARE WORD OPERANDS; RESULT IS A DOUBLEWORD
             	MOV  	BX,VALUE1	;BX=MULTIPLIER
             	MOV  	CX,VALUE2	;CX=MULTIPLICAND
             	SUB  	AX,AX		;CLEAR AX 
             	MOV  	DX,AX		;CLEAR DX
   BACK: 	ADD  	AX,BX		;ADD BX TO AX 
             	ADC  	DX,00		;ADD CARRIES IF THERE IS ONE
             	LOOP 	BACK		;CONTINUE UNTIL CX=0
             	MOV  	RESULT,AX	;SAVE THE LOW WORD 
             	MOV  	RESULT+2,DX	;SAVE THE HIGH WORD
             	ENDM
   ;--------------
   		.MODEL SMALL
		.STACK 64
   ;--------------
   		.DATA
   RESULT1 	DW        	2 DUP (0)
   RESULT2 	DW        	2 DUP (0)
   RESULT3 	DW        	2 DUP (0)
   ;--------------
   		.CODE
   MAIN      	PROC  	FAR
             	MOV  	AX,@DATA
             	MOV  	DS,AX
             	MULTIPLY 2000,500,RESULT1
             	MULTIPLY 2500,500,RESULT2
             	MULTIPLY   300,400,RESULT3
             	MOV  	AH,4CH
             	INT  	21H            		;GO BACK TO DOS
   MAIN      	ENDP
                END     MAIN