记得以前有一个程序，
mov ax,0201
mov bx,0200
mov cx,0001
mov dx,0080
int 13
int 20
完事以后，去哪个地址查看来的， 我想不起来了。

int13h,ah=2的用法是这样的
AH = 02h
AL = number of sectors to read (must be nonzero)
CH = low eight bits of cylinder number
CL = sector number 1-63 (bits 0-5)
high two bits of cylinder (bits 6-7, hard diskonly)
DH = head number
DL = drive number (bit 7 set for hard disk)
ES:BX -> data buffer
这代码是读取硬盘(80h),但只能在实模式下运行,且不能读取EFI(非MBR)的结构。