This document contains assembly code to perform addition of: 1) Two 16-bit BCD numbers with carry, with the result stored in memory location 2004h. 2) Two 32-bit numbers stored in memory locations 2000h-2002h and 2004h-2006h, with the result stored in 2008h-200Ah. 3) Two signed 32-bit numbers stored in memory locations 2000h-2002h and 2004h-2006h, with the result stored in 2008h-200Ah. The code performs the additions by loading the operands from memory into registers, performing the addition, and storing the results back to memory.

1. C:HomeNIT0_ClassAutumn 2012Microprocessor Labup Programs8086up_8086_Q1.asm 04 August 2012 23:30
; Q 1>
; a> Addition of 2 16bit BCD numbers with carry
SW 2000h
[2000h] = 0999h ; A = 999 in BCD
[2002h] = 0001h ; B = 1 in BCD
[2004h] = (ans) ; C = (A + B) in BCD
.
A
1000h
mov ax, [2000h]
mov bx, [2002h]
add bx, ax
mov al, bl
daa
adc bh, 00h
mov bl, al
mov al, bh
daa
mov bh, al
mov [2004h], bx
hlt
.
GO 1000h
INT ; (try '.' here)
SW 2004h ; ans = 1000h
. ; => 1000 in BCD
; b> Addition of 2 32bit numbers
SW 2000h
[2000h] = 4B20h ; A = 12340000
[2002h] = 00BCh ;
[2004h] = 162Eh ; B = 5678
[2006h] = 0000h ;
[2008h] = (ans) ; C = (A + B)
[200Ah] = (ans) ;
.
A
1000h
mov ax, [2000h]
mov bx, [2002h]
add ax, [2004h]
adc bx, [2006h]
mov [2008h], ax
mov [200Ah], bx
hlt
.
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2. C:HomeNIT0_ClassAutumn 2012Microprocessor Labup Programs8086up_8086_Q1.asm 04 August 2012 23:30
GO 1000h
INT ;(try '.' here)
SW 2008h ; ans = 614Eh
SW 200Ah ; ans = 00BCh
. ; => 12345678
; c> Addition of 2 signed 32bit numbers
SW 2000h
[2000h] = 614Eh ; A = 12345678
[2002h] = 00BCh ;
[2004h] = 0E9D2h ; B = -5678
[2006h] = 0FFFFh ;
[2008h] = (ans) ; C = (A + B)
[200Ah] = (ans) ;
.
A
1000h
mov ax, [2000h]
mov bx, [2002h]
add ax, [2004h]
adc bx, [2006h]
mov [2008h], ax
mov [200Ah], bx
hlt
.
GO 1000h
INT ;(try '.' here)
SW 2008h ; ans = 4B20h
SW 200Ah ; ans = 00BCh
. ; => 12340000
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