MS-DOS Function Calls - 1

MS-DOS Function Calls - 1

Required reading: Chapter 13

1.Write a program that inputs a single character and redisplays (echoes) it back to the screen. Hint: Use INT 21h for the character input. Solution program .

2.Write a program that inputs a string of characters (using a loop) and stores each character in an array. Using CodeView, display a memory window containing the array. Solution program.

(Contents of memory window after the loop executes:)

000A 41 42 43 44 45 46 47 48 49 4A 4B 4C 4D ABCDEFGHIJKLM 0017 4E 4F 50 51 52 53 54 00 4E 4E 42 30 38 NOPQRST.NNB08

3.Using the array created in the previous question, redisplay the array on the screen. Solution program.

4.Write a program that reads a series of ten lowercase letters from input (without displaying it), converts each character to uppercase, and then displays the converted character. Solution program.

5.Write a program that displays a string using INT 21h function 9. Solution program.

http://www.nuvisionmiami.com/books/asm/workbook/msdos1.htm [1/15/2003 4:44:02 PM]

http://www.nuvisionmiami.com/books/asm/workbook/dos1-1.asm

;Problem statement:

;Write a program that inputs a single character and redisplays ;(echoes) it back to the screen. Hint: Use INT 21h for the ;character input.

INCLUDE Irvine16.inc

.code main proc

mov ax,@data mov ds,ax

http://www.nuvisionmiami.com/books/asm/workbook/dos1-1.asm [1/15/2003 4:44:03 PM]

http://www.nuvisionmiami.com/books/asm/workbook/dos1-2.asm

; Problem statement:

;Write a program that inputs a string of characters ;(using a loop) and stores each character in an array. ;Display a memory dump in CodeView showing the array.

INCLUDE Irvine16.inc

.data COUNT = 20

charArray db COUNT dup(0),0

.code main proc

mov ax,@data mov ds,ax

mov si,offset charArray mov cx,COUNT

main endp end main

http://www.nuvisionmiami.com/books/asm/workbook/dos1-2.asm [1/15/2003 4:44:03 PM]

http://www.nuvisionmiami.com/books/asm/workbook/dos1-3.asm

; Problem statement:

;Write a program that inputs a string of characters ;(using a loop) and stores each character in an array. ;Redisplay the array at the end of the program.

INCLUDE Irvine16.inc

.data COUNT = 20

charArray db COUNT dup(0),0

.code main proc

mov ax,@data mov ds,ax

mov si,offset charArray mov cx,COUNT

main endp end main

http://www.nuvisionmiami.com/books/asm/workbook/dos1-3.asm [1/15/2003 4:44:04 PM]