This document contains assembly code to perform multiplication operations on the 8086 microprocessor. It includes: 1) Multiplication of two 32-bit numbers stored in memory locations 2000h-200Eh, with the 64-bit result stored in locations 2008h-200Eh. 2) Multiplication of two signed 16-bit numbers stored in locations 2000h-2002h, with the 32-bit result stored in locations 2004h-2006h. The code performs the multiplications using MUL and IMUL instructions, storing intermediate and final results back to memory.

1. C:HomeNIT0_ClassAutumn 2012Microprocessor Labup Programs8086up_8086_Q3.asm 05 August 2012 10:37
; Q 3>
; a> Multiplication of 2 32bit numbers
SW 2000h
[2000h] = 0A120h ; A = 500000
[2002h] = 00007h ;
[2004h] = 04240h ; B = 1000000
[2006h] = 0000Fh ;
[2008h] = (ans) ; C = (A * B)
[200Ah] = (ans) ;
[200Ch] = (ans) ;
[200Eh] = (ans) ;
.
A
1000h
mov ax, 0000h
mov [2008h], ax
mov [200Ah], ax
mov [200Ch], ax
mov [200Eh], ax
mov ax, [2000h]
mov bx, [2004h]
mul bx
mov [2008h], ax
mov [200Ah], dx
mov ax, [2000h]
mov bx, [2006h]
mul bx
add [200Ah], ax
adc [200Ch], dx
adc w.[200Eh], 0000h
mov ax, [2002h]
mov bx, [2004h]
mul bx
add [200Ah], ax
adc [200Ch], dx
adc w.[200Eh], 0000h
mov ax, [2002h]
mov bx, [2006h]
mul bx
add [200Ch], ax
adc [200Eh], dx
hlt
.
GO 1000h
INT ;(try '.' here)
SW 2008h ; ans = 8800h
SW 200Ah ; ans = 6A52h
SW 200Ch ; ans = 0074h
SW 200Eh ; ans = 0000h
. ; => 500000000000
-1-

2. C:HomeNIT0_ClassAutumn 2012Microprocessor Labup Programs8086up_8086_Q3.asm 05 August 2012 10:37
; b> Multiplication of 2 signed 16bit numbers
SW 2000h
[2000h] = 003E8h ; A = 1000
[2002h] = 0FFF6h ; B = -10
[2004h] = (ans) ; C = (A * B)
[2006h] = (ans) ;
.
A
1000h
mov ax, [2000h]
mov bx, [2002h]
imul bx
mov [2004h], ax
mov [2006h], dx
hlt
.
GO 1000h
INT ;(try '.' here)
SW 2004h ; ans = 0D8F0h
SW 2006h ; ans = 0FFFFh
. ; => -10000
-2-