Hi everyone i'm new in assembly language.i try to code for 1's complement but not working.is there anyone who can detect my error code is Code: Title Length of an array .model small .stack 100h .data msg0 db 0dh,0ah, 'Enter the binary value : $' msg1 db 0dh,0ah, 'the 1s complement form is: $' str1 db 255 dup (?) one db ? two db ? .code main proc mov ax,@data mov ds,ax lea dx,msg0 mov ah,09h int 21h lea si,str1 ; read a string mov ah,01h read: int 21h ;mov bl,al cmp al,0dh; carrage return je display; if input is a carrege return than jump display section cmp al,00h je _0_ cmp al,01h je _1_ _0_: mov al,30h mov [si],al inc si jmp read _1_: mov al,31h mov [si],al inc si jmp read display: mov al,'$' mov [si],al lea dx,msg1 mov ah,09h int 21h lea dx, str1 mov ah,09h int 21h mov ah, 4ch int 21h main endp end main thanks everyone