Princess Nora Bint Abdulrahman University
Faculty of Computer and Information Science
CS 321 :Computer Organization and assembly language
First Semester 1432/1433H
Lab Model Answers
CS321Lab
ModelAnswers
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L. Aseel AlDabjan
Princess Nora Bint Abdulrahman University
Faculty of Computer and Information Science
CS 321 :Computer Organization and assembly language
First Semester 1432/1433H
Lab Model Answers
First Lab :
Q : Write a program which display ? for the user to enter a letter from the keyboard and display the letter on
next line.
Note: Comments are necessary in your code.
Sample Execution:
Input
?s
SOLUTION :
.MODEL SMALL
.STACK 100H
.DATA
.CODE
MAIN PROC
; initialize DS
MOV AX, @DATA
MOV DS, AX
; To display ? on screen for user input
MOV AH,2
; display character function
MOV DL,'?'
; character is ?
INT 21h
; display it
;Ready to Input from keyboard
MOV AH, 1
INT 21H
MOV BL,AL ; Save it to other safe data register
;To go to next line
MOV AH,2
MOV DL,0DH
; for carriage return
INT 21h
MOV DL,0AH
; for line feed ( going to beginning of next line)
INT 21h
;Display the input Character
MOV AH,2
; display character function
MOV DL, BL
; character is in BL
INT 21h
; display it
;return to DOS
MOV
AH, 4CH
INT
21h
; Dos exit
MAIN
ENDP
END
MAIN
٢
L. Aseel AlDabjan
Princess Nora Bint Abdulrahman University
Faculty of Computer and Information Science
CS 321 :Computer Organization and assembly language
First Semester 1432/1433H
Lab Model Answers
Second Lab
Q: Write a program which display "Welcome to CS321 "
Note: Comments are necessary in your code.
Sample Execution:
Welcome to CS321
SOLUTION :
.MODEL SMALL
.STACK 100H
.DATA
MSG
DB
' Welcome to CS321
$'
.CODE
MAIN PROC
; initialize DS
MOV AX,@DATA
; get data segment
MOV DS,AX
; initialize DS
; display message
LEA DX,MSG
; get message
MOV AH,9
; display string function
INT 21H
; display message
; return to DOS
MOV AH, 4CH
INT 21H
; DOS exit function
; exit to DOS
MAIN ENDP
END MAIN
٣
L. Aseel AlDabjan
Princess Nora Bint Abdulrahman University
Faculty of Computer and Information Science
CS 321 :Computer Organization and assembly language
First Semester 1432/1433H
Lab Model Answers
Third
hird Lab (practice on arithmetic operation):
Q: Write a program which ask user to input two Decimal Numbers whose sum is less than 10 and display
their sum in next line .
Sample execution:
Enter two Decimal Numbers whose sum is less than 10 : 27
The sum is : 9
SOLUTION :
Input
.MODEL SMALL
.STACK 100H
.DATA
MSG DB ' ENTER two Decimal Numbers whose sum is less than 10: $'
MSG1 DB 0AH,0DH,'THE SUM is : $'
C2 DB ?
.CODE
Main PROC
MOV AX,@DATA
; initialize DS
MOV DS,AX
LEA DX,MSG
;display the first message
MOV AH,9
INT 21H
MOV AH,1
INT 21H
; read and store 1st digit
MOV BL,AL
INT 21H
; read and store 2nd digit
MOV C2,AL
٤
L. Aseel AlDabjan
Princess Nora Bint Abdulrahman University
Faculty of Computer and Information Science
CS 321 :Computer Organization and assembly language
ADD BL,C2
; add the two numbers
SUB BL,30H
; *
LEA DX,MSG1
; display second message
First Semester 1432/1433H
Lab Model Answers
MOV AH,9
INT 21H
MOV AH,2
; display result
MOV DL,BL
INT 21H
;return to DOS
MOV AH,4CH
INT 21H
Main ENDP
END Main
* when we add the two numbers , suppose we enter 2 and 7
Their ASCII code are 32h and 37h respectively, after
adding BL will contais 69h , now we have to SUB 30h to
get the ASCII code of 9 and it is 39h.
٥
L. Aseel AlDabjan
Princess Nora Bint Abdulrahman University
Faculty of Computer and Information Science
CS 321 :Computer Organization and assembly language
First Semester 1432/1433H
Lab Model Answers
Forth Lab (practice on if statement)
Q1 :Write a program to read two digit from(0-9), and display them on the next line in manner order
Sample execution:
Inpu
Output of Program:
ts
Enter the first digit : 9
Enter the second digit : 2
The given digits in manner order are: 2 9
Solution:
.MODEL SMALL
.STACK 100H
.DATA
MSG DB 'Enter the first digit:$'
MSG1 DB 0DH,0AH, 'Enter the second digit: $'
MSG2 DB 0DH,0AH, 'The given digits in manner order:$'
.CODE
MAIN PROC
MOV AX, @DATA
MOV DS, AX
; initialize DS
MOV AH,9
; display the string MSG
LEA DX, MSG
INT 21h
; read first digits and store it in BL
MOV AH,1
INT 21h
MOV BL,AL
; display the string MSG1
MOV AH,9
LEA DX, MSG1
INT 21h
; read second digits and store it in BH
Mov AH,1
INT 21h
MOV BH, AL
; Check if the digits are in manner order,
; if not then switch them
CMP BL, BH
JLE DISPLAY
XCHG BL, BH
DISPLAY:
MOV AH,9
LEA DX, MSG2
INT 21h
; display the string MSG2
٦
L. Aseel AlDabjan
Princess Nora Bint Abdulrahman University
Faculty of Computer and Information Science
CS 321 :Computer Organization and assembly language
First Semester 1432/1433H
Lab Model Answers
; display the digits
MOV AH, 2
MOV DL, BL
INT 21h
MOV DL, BH
INT 21h
; exit to DOS
MOV AH,4CH
INT 21H
MAIN ENDP
end main
٧
L. Aseel AlDabjan