dseg segment

dseg ends

sseg segment stack
        dw 100h dup(?)
sseg ends

cseg segment
assume  ds:dseg,cs:cseg,ss:sseg,ES:DSEG
start:  mov ax,dseg
        mov ds,ax

        mov ah,0
        mov al,1
        mov bl,2
        mov cx,4


        x: dec cx
        add ah,al
        add al,bl
        cmp cx,0
        jnz x


        mov ah,4ch
        int 21h
cseg ends
end start