这是一个字母或数制之间的转化程序，5为主模块，调用模块1和模块7

模块1又调用模块2、3、4和6四个模块，其中：

　　模块2实现小写字母向大写字母的转换

模块3实现大写字母向小写字母的转换

模块4实现二进制数向十六进制数的转换

模块6实现十六进制数向二进制数的转换

模块7实现十六进制数向十进制数的转换

按“q”键退出。

使用时，需将7个文件分别汇编，连接的方法为：

5＋1＋2＋3＋4＋6＋7

生成可执行文件“5”　即可运行。-This a letter or number into the system procedures, five main modules, a module called seven modules and module also a module called 2,3,4 and 6 four modules, including : two modules to achieve lowercase letters to uppercase conversion module 3 to achieve capital letters lowercase letters to the four conversion modules to achieve binary hexadecimal number of conversion modules to achieve 6 hexadecimal number to the number of binary conversion modules seven achieve hexadecimal number to the number of metric conversion by "q" key to exit. When used, the need to document seven separate compilation, linking method : 5 +1 +2 +3 +4 +6 +7 generate executable file "5" can run.