本实验通过DOS功能调用编制和调试一个自制时钟程序，要求设置一个新的1ch中断处理程序并常驻内存，实现在屏幕右上角显示当时的时间：按XX:XX:XX形式显示，并且能正确进位，24小时应消零。同时，在显示时间时，DOS系统能正确处理各种命令，正确执行应用程序。-This experiment DOS function calls through the establishment and commissioning of a self-clock procedures, require the establishment of a new 1ch interrupt handling procedures and permanent memory, to achieve the upper right corner of the screen showing that the time: by XX: XX: XX form, and correctly binary, 24 hours should be zero extinction. At the same time, show time, DOS system can correctly handle a variety of command, the correct implementation of applications.