说明：  这个程序用180行C代码就能够读取FAT16文件系统U盘的根目录,可以看到根目录下的文件 名,并可显示 首文件内容,不过,该程序很不严谨,也没有任何错误处理,对U盘兼容性较差,只是用于简单试 验,作为参考
(this procedure with 180 OK C code can be read FAT16 file system U disk root directory. can see the root directory under the file name, would show the first contents of the documents, but the very stringent procedures, no error handling, the U disk compatibility poor, but for a simple test, as a reference)