;==============================================================================
;file        :ten.asm
;author      :Andre Long
;due         :May 15, 2006
;description :This program will multiply two ten digit numbers with arrays
;==============================================================================
                             ;procedures to
              INCLUDE	Pcmac.inc
              EXTRN		NEWLINE:FAR			;display a new line
              EXTRN		GETDEC$:FAR			;gets 16 bit decimal value unsigned
              EXTRN		PUTDEC$:FAR			;display 16 bit value unsigned
              EXTRN		PUTSTRNG:FAR		;display charactor string
;==============================================================================
				.MODEL	SMALL
				.586
				.STACK	100h
.DATA
;n1		DB	1,2,3,4,5,6,7,8,9,0	
;n2		DB	9,8,7,6,5,4,3,2,1,1	
n1		DB	1,1,1,1,1,1,1,1,1,1	
n2		DB	0,9,8,7,6,5,4,3,2,1
tempA	DB	20	DUP	(0)
tempB	DB	20	DUP	(0)
result	DB	20	DUP	(0)
messP	DB	'Product = ',	'$'
messTA	DB	'TempA = ',	'$'
messTB	DB	'TempB = ',	'$'
endPos	DW	9
tempEndPos	DW	19
carry	DB	?
carryX	DB	0
blank	DB	' ', '$'
red		DB	?
counter	DB	?
;==============================================================================
.CODE
ten2			proc
				_Begin	
				
				mov		ax,	0
				mov		bx,	0
				mov		cx,	0
				mov		dx,	0
				mov		si,	endPos
				mov		di,	endPos
				mov		bx,	tempEndPos

outerLoop:		mov		bx,	tempEndPos
				mov		si,	endPos
				cmp		di,	8
				jl		doneOuterLoop
				jmp		innerWorks
				
			
				innerWorks:
							mov	al,	[n1 + si]
							mov	dl,	[n2 + di]
							mul	dl				;al = (al)(dl)
							add	al,	carryX
							
					ptA:	cmp		al,	9	
							jg		carryM
							jmp		noCarryM		
												
				carryM:		mov		red,	10
							div		red		;al / 10
							mov		[tempA + bx],	ah		;remainder to current end position
							mov		carryX,	al				;store the quotient
							jmp		afterCarryM
												
				noCarryM:	mov		[tempA + bx],	al
							jmp		afterCarryM		
												
												
			afterCarryM:	dec		bx
							dec		si
							cmp		si,	0
							jl		nextN2			
				            jmp		innerWorks		;di not less < 0 (have not reach end of n1)
				            
				
				nextN2:		push	di
							sub		di,	9
							mov		counter,	di	;counter = di - 9
							pop		di
				
							cmp		di,	9
							je		somePoint
							jmp		nextN22
				
				nextN22:	mov		bx,	0
				nextN222:	mov		cl,	[tempA + bx]	;shift logic
							mov		[tempA + bx -1],	cl
							inc		bx
							cmp		bx,	19
							jg		somePoint3
							jmp		nextN222
				somePoint3:	mov		[tempA + 19],	0
				
				somePoint:	mov		bx,	tempEndPos
					
				somePoint2:	mov		cl,	[tempA + bx]
							add		[result + bx],	cl
	
							cmp		[result + bx],	9
							jg		carry1
							jmp		noCarry1
							
				carry1:		sub		[result + bx],	10			;cl - 10
							mov		carry,	1		;carry = 1
							
							mov		dl,		carry
							add		[result + bx - 1],	dl
							jmp		afterCarry1
							
				noCarry1:	
							jmp		afterCarry1
							
							
			afterCarry1:	dec		bx
							cmp		bx,	0
							jl		testDi
							jmp		somePoint2
		
			testDi:			dec		di	
							jmp		outerLoop
			
doneOuterLoop:					
			
			mov		bx,		0
			call	newline
display:	mov		al,		[result + bx]
			call	putdec$
			sPutstr	blank
			inc		bx
			cmp		bx,	19
			ja		outP
			jmp		display


outP:

				
				_Exit
ten2			ENDP
				END		ten2