引言为了避免微型机在切断电源时程序和常数等有关讯息的丢失。人们除了将常用的基本程序和数据(如引导程序、监控程序及专用程序等)进行固化处理存放在ROM或EPROM中之外,一般把其它的系统软件、应用软件和数据文件存放在磁盘或磁带等外存贮器中,而在需要时调入内存。使用磁盘作为外存贮器虽然具有使用灵活方便,存取速度快等优点,但因其价格昂贵,控制也比较复什,因而仅在中高档微型机中得到普遍采用。与其相反,应用盒式磁带机作为 Introduction In order to avoid the microcomputer in the power off program and constants and other related information loss. In addition to storing frequently used basic programs and data (such as boot programs, monitor programs, special programs, etc.) in ROM or EPROM, other system software, application software and data files are generally stored on a magnetic disk or tape Other memory, and when needed, transferred to memory. The use of a magnetic disk as an external memory has the advantages of being flexible and convenient in use and having quick access speed. However, the use of a magnetic disk as an external memory is relatively common in medium and high-end microcomputers due to its high cost and control. In contrast, use a tape cartridge as the