fat格式文件的读写操作，针对SD卡，C语言环境-fat file format to read and write operations, for SD Card, C language environment

常用的几种FAT文件系统合集，包括UCFS、FATFS、ZLGFAT等，对各个文件系统有详细的介绍资料-Several commonly used FAT file system collection, including UCFS, FATFS, ZLGFAT and so on, all file systems are described in detail the information