COLLEGE OF ENGINEERING
DEPARTMENT OF COMPUTER ENGINEERING
ECCE -303 COMPUTER ARCHITECTURE AND ORGANIZATION
First Semester 2022-2023
ILOs: B1, B2, B3, C1, D1
Mohammed Jasim Ahmed Fadhul
202010488
LAB 6: Interrupt DOS – Calculate the factorial
Objectives:
To write a complete assembly program using interrupt 21h.
Exercise 1:
Write an assembly program that allows the user to enter 1 number between 1 and 4 from the
keyboard and display the factorial of these numbers. (use int 21h=01 and int 21h=02)
include "emu8086.inc"
org 100h
print "Enter a number"
printn
mov ah,01
int 21h
sub al,30h
cmp al,1
je L2
mov bl,al
Label1: sub bl,1
mul bl
cmp bl,1
jne Label1
mov bl,10
div bl
mov cl, al
mov ch,ah
mov dl,33 ;!sign
mov ah,02
int 21h
