FAT
(File Allocation Table) The part of the DOS, Windows 95 and OS/2 file system that keeps track of where data is stored on disk. When the disk is high-level formatted, the FAT is recorded twice and contains a table with an entry for each disk cluster.
The directory list, which contains file name, extension, date, etc., points to the FAT entry where the file starts. If a file is larger than one cluster, the first FAT entry points to the next FAT entry where the second cluster of the file is stored and so on to the end of the file. If a cluster becomes damaged, its FAT entry is marked as such and that cluster is not used again.

flash BIOS
A PC BIOS that is stored in flash memory rather than in a ROM. Flash BIOSs can be updated in place, whereas ROM BIOSs must be replaced with a newer chip.

flash memory
A memory chip that holds its content without power, but must be erased in fixed blocks rather than single bytes. Block sizes typically range from 512 bytes up to 256KB. The term was coined by Toshiba for its ability to be erased "in a flash." Derived from EEPROMs, flash chips are less expensive and provide higher bit densities. Flash is also becoming an alternative to EPROMS, because it can be easily updated.
Flash memory is used in PCMCIA memory cards, PCMCIA flash disks and other types of solid state disks, embedded controllers and smart cards. It typically has a lifespan of 100K write cycles, but newer chips can be written a million times.

FPU
(Floating Point Unit) A computer circuit that handles floating point operations.

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