Microsoft* Flash File System

The Microsoft* Flash File System allows a PCMCIA flash memory card to behave as a magnetic disk drive. The MS-DOS FAT file system is not suitable for flash memory; due to its nature, it will wear out the flash memory unevenly. The Microsoft Flash File System was specially designed to address unique requirements of flash memory technology. The Flash File System consists of two device drivers- the first, high-level file system driver (MSFLASH), implements the logic of the flash file and passes I/O to the second dri-ver, a low-level flash device driver (CARDDRV), which interacts directly with the system interface to the flash memory device. This low-level driver can be modified easily to support various implementation of the target system. The Flash File System drivers are loaded into the CONFIG.SYS file along with MS-DOS. During system initialization, MS-DOS initializes flash memory as a redirected system drive. The Flash File System minimizes data fragmentation and ensure uniform use of all blocks and even wear of flash memory. The Flash File System preserves data integrity by verifying that data is not stored on corrupted physical media and by shutting down the bad blocks.