MCSL 017 C and Assembly Language Programming 16-17

MCSL 017 

MCA 1st semester 

Section 2: Assembly Language Programming Lab

(c) Write a program in assembly language for reversing a four byte string.

DATA SEGMENT

STR1 DB "DATA$"

STR2 DB 7 DUP ('$')

MSG1 DB 10,13,'STORED STRING IN MEMORY IS : $'

MSG2 DB 10,13,'REVERSE STRING IS : $'

DATA ENDS

DISPLAY MACRO MSG

MOV AH,9

LEA DX,MSG

INT 21H

ENDM

CODE SEGMENT

ASSUME CS:CODE,DS:DATA

START:

MOV AX,DATA

MOV DS,AX

DISPLAY MSG1

DISPLAY STR1

LEA SI,STR2

LEA DI,STR1

ADD DI,3

MOV CX,4

REVERSE:

MOV AL,[DI]

MOV [SI],AL

INC SI

DEC DI

LOOP REVERSE

DISPLAY MSG2

DISPLAY STR2

MOV AH,4CH

INT 21H

CODE ENDS