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.这个程序可以支持WINDOWS按FAT16格式化的U盘,因为程序精简,所以只兼容超过50％以上的U盘品牌,如果换成CH375A芯片则兼容性可提高到85％,当然,如果使用WCH公司的子程序库或者正式版本的C源程序兼容性更好
(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. This procedure can be supported by Windows FAT16 formatted USB procedural streamlining, So only with more than 50% of the U disk brands, If the chip is replaced by CH375A compatibility can be increased to 85%, of course, If the use of WCH the subroutine library or an official version of the C source files better compatibility)