在DOS环境下，使用内存是个令人头痛的问题，由于640K的限制很多功能不能实现，这篇文章介绍了在DOS下使用扩展内存的方法，很值得借鉴。-In the DOS environment, the use of memory is a headache, due to restrictions on 640K a lot of features can not be achieved, this article describes the use of extended memory DOS method, it is worth learning from.