vtu 4th sem microprocessors hardware programs

program 2.b as per syllebus

.model small
.code
        mov dx,0e803h
        mov al,80h
        out dx,al
        mov al,0
        mov dx,0e800h
     up:out dx,al
        call delay
        add al,1
        daa
        call stop
        cmp al,99
        jne up
   down:out dx,al
        call delay
        add al,99
        daa
        call stop
        cmp al,0
        jne down
   stop:push ax
        mov ah,1
        int 16h
        jnz exit
        pop ax
        ret
   exit:mov ah,4ch
        int 21h
   delay:mov si,2fffh
   ret2: mov di,0ffffh
   ret1: dec di
         jnz ret1
         dec si
         jnz ret2
         ret
         end