Question

8086 Microprocessor
Write an ASSEMBLY program that is capable of copying a string in reversed order
For Example:
If entered: Hello World!
The string in reversed order must be:
!dlroW olleH

*MUST USE ASSEMBLY LANGUAGE *

Answer 1

Data Segment
  str db \'String_Reverse\',\'$\'  
  strlen dw $-str
  strrev db 20 dup(\' \')
Data Ends

Code Segment
  Assume cs:code, ds:data
  Begin:
    mov ax, data
    mov ds, ax
    mov es, ax
    mov cx, strlen
    add cx, -2
    lea si, str
    lea di, strrev
    add si, strlen
    add si, -2
    L1:
       mov al, [si]
       mov [di], al
       dec si
       inc di
       loop L1
       mov al, [si]
       mov [di], al
       inc di
       mov dl, \'$\'
       mov [di], dl
    Print:
       mov ah, 09h
       lea dx, strrev
       int 21h
    Exit:
       mov ax, 4c00h
       int 21h
Code Ends
End Begin