code segment assume cs:code,ds:code org 100h begin: xor ax,ax mov dl,80h int 13h ;复位硬盘 mov ax,201h mov bx,200h mov cx,1 mov dx,80h int 13h ;读主引导扇区到200H mov cx,ds:[3d0h] mov [3ceh],0 mov bx,210h mov ax,301h int 13h ;写扩展分区首隐藏扇区