mov ax,5301h sub bx,bx int 15h jb stop mov ax,530eh sub bx,bx int 15h jb stop mov ax,5307h mov bx,0001h mov cx,0003h int 15h stop: int 20h
или
mov ax,5301h sub bx,bx int 15h jc @@finish mov ax,530Eh sub bx,bx mov cx,102h int 15h jc @@finish mov ax,5307h mov bx,1 mov cx,3 int 15h @@finish: int 20h