CODEWITHSUNDEEP
assemblyx86dosmasm
programmer
programmer

Reputation: 57

Error in string reversal code

What's wrong with this code? I am expecting this program to reverse the string and display it.

;String reverse (Problem is it is displaying any output)
.model small
.stack 100h
.data
    text1 db 'HELLO WORLD $'
    text2 db  13 dup(?)
    count dw   13
.code
  main proc
    mov ax, @data
    mov ds,ax
    mov es,ax
    mov cx,count
    mov si,0
    mov di,0
    add di,count
    dec di

again:  mov al,text1[si]
    mov text2[di],al
    inc si
    dec di
    loop again

    lea dx,text2
    mov ah,9
    int 21h

    mov ah,4ch
    int 21h
  main endp
end main

Upvotes: 1

Views: 51

Answers (1)

Sep Roland
Sep Roland

Reputation: 39166

When reversing (and hoping to display the result!) you should not allow for the original $ character to be moved to the beginning of the result.

Setting count to 12 in stead of 13 should do the trick provided you change the definition of text2:

text2 db  12 dup(?), "$"

Upvotes: 3

Related Questions