说明：  设计题目:读写磁盘文件 设计要求：能正确执行对硬盘文件的读写 设计应用：熟练基本的汇编编程，为后来编程打基础。 设计思路：反复利用DOS系统功能调用，进行操作。
(design topics : read and write disk file design requirements : the correct implementation of the document literacy drive design applications : a compilation of basic proficiency in programming, laying the foundation for the subsequent programming. Design Idea : repeated use DOS system function calls, to operate.)