当PC启动时,Intel系列的CPU首先进入的是16位实地址模式,并开始执行位于内存地址0xFFFF：0000处的代码,也就是ROM-BIOS起始位置的代码。-When the PC starts, CPU of Intel series what to get into is 16 on-the-spot address modes first, and start carrying out to be located in a memory address 0 xFFFFs:0000 cod