.MODEL SMALL
.STACK 200H
.DATA

            MSG1 DB 10,13,'Enter a string :- $'
            MSG3 DB 10,13,'Length of this string :- $'
            MSG4 DB 10,13,'Not a Palindrome $'
            MSG5 DB 10,13,'Palindrome $'
            MSG6 DB 10,13,'Reversed string is :- $'
            P1 LABEL BYTE
            M1 DB 0FFH
            L1 DB ?
            P11 DB 0FFH DUP ('$')
                P22 DB 0FFH DUP ('$')
        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

    LEA DX,P1
    MOV AH,0AH
    INT 21H


    DISPLAY MSG3

    MOV DL,L1
    ADD DL,30H
    MOV AH,2
    INT 21H

    DISPLAY MSG6

    LEA SI,P11
    LEA DI,P22

    MOV DL,L1
    DEC DL
    MOV DH,0
    ADD SI,DX
    MOV CL,L1
    MOV CH,0

REVERSE:
        MOV AL,[SI]     ;reverse the string at first
        MOV [DI],AL
        INC DI
        DEC SI
        LOOP REVERSE

    DISPLAY P22

    LEA SI,P11
    LEA DI,P22

    MOV CL,L1
    MOV CH,0

CHECK:
        MOV AL,[SI]
        CMP [DI],AL             ; if the reverse string as same as previous string
        JNE NOTPALIN
        INC DI                  ; then it is Palindrome
        INC SI
        LOOP CHECK              ; otherwise not Palindrome


    DISPLAY MSG5
    JMP EXIT
NOTPALIN:
        DISPLAY MSG4

EXIT:   MOV AH,4CH
        INT 21H
CODE ENDS
END START