CSEG segment org 100h _start mov ax 0B800h mov es ax mov di mov ah 31

CSEG segment
org 100h

_start:
        mov ax, 0B800h
        mov es, ax
        mov di, 0

        mov ah, 31
        mov al, 1
        mov es:[di], ax

        mov ah, 10h
        int 16h

        int 20h

        CSEG ends
end _start