Implementation of assembly using string detection scasb search number position

stack   segment
 db 1024 dup(?)
stack   ends
 
data    segment
 buff  db 64h,45h,42h,78h,89h
data    ends
 
code    segment
 assume cs:code,ds:data,ss:stack
start:   mov ax,data
      mov ds,ax
      mov es,ax
      mov di,offset buff
      mov al,42h
      mov cx,lengthof buff
      cld
again:   scasb
      je next
      loop again
      
next:   mov dl,cl
      mov al,dl
      call ALdisp
      mov ah,4ch
      int 21h
      
    ALdisp proc
    push ax
    push cx
    push dx
    push ax
    mov dl,al
    mov cl,4
    shr dl,cl
    or dl,30h
    cmp dl,39h
    jbe aldisp1
    add dl,7
aldisp1:mov ah, 2
    int 21h
    pop dx
    and dl,0fh
    or dl,30h
    cmp dl,39h
    jbe aldisp2
    add dl,7
aldisp2: mov ah,2
    int 21h
    pop dx
    pop cx
    pop ax
    ret
ALdisp endp
 
code    ends
end    start