磁盘扇区存储数据，完成读写功能。在MSDN中可以找到相似的代码。-Disk data storage sector, the completion of read and write functions. MSDN can be found in the code is similar.

读取SD卡的磁盘数据，本功能主要是读取一个扇区的数据，其他的扇区同理。-SD card read disk data, the main function is to read a sector of data, other sectors empathy.