data segment
led db 3fh,06h,5bh,4fh,66h,6dh,7dh,07h,7fh,6fh
buffer1 db 0,0,0,0
bz dw ?
data ends
code segment
    assume cs:code,ds:data
start: mov ax,data
       mov ds,ax
       push ds
       mov ax,0000h
       mov ds,ax
       add ax,2000h
       mov [si],ax
       ;8255
       mov dx,28bh
       mov al,81h
       out dx,al
       mov DI,offset buffer1
  loop1:mov cx,0300h
  loop2: mov bh,02
  LLL:mov byte ptr bz,bh
     push di
     dec di
     add di,bz
     mov bl,[di]
     pop di
     mov bh,0
     mov si,offset led
     add si,bx
     mov al,byte ptr [si]
     mov dx,288h
     out dx,al
     mov al,byte ptr bz
     mov dx,28ah
     out dx,al
     push cx
     mov cx,3000
delay:loop delay
    pop cx
    mov bh,byte ptr bz
    shr bh,1
    jnz LLL
    loop loop2
    mov ax,word ptr [di]
    cmp ah,09
    jnz set
    cmp al,09
    jnz set
    mov ax,0000
    mov  [di] ,al
    mov [di+1],ah
    jmp loop1
set:mov dx,0ffh
    mov ah,06
    int 21h
    jnz exit
    mov ax,word ptr [di]
    inc al
    AAA
    mov [di],al
    mov [di+1],ah
    jmp loop1
exit:mov dx,28ah
     mov al,0
     out dx,al
     mov ah,4ch
     int 21h
code ends
     end start