A flash memory device is a computer chip with ROM that retains its data when the power is shut down; it can be electronically erased and be reprogrammed without needing to be physically removed from a computer's circuit board.



Flash memory has become a very hot topic, for as technology progresses in line with Moore's Law it becomes possible to store ever more data on a small flash memory drive and the portability of the drive makes it amazingly convenient. The USB portable flash memory drive is one of the biggest selling electronic items in the Western world at the time of this writing.

These ubiquitous devices are increasingly used by computer techs who are upgrading a client's computer programs, university professors and students, and businessmen for meetings and presentations. The small, easily stored device simply plugs into any computer's USB port and uploads their stored memory to the computer on command. They can also store new memories that the user downloads from the computer or the Internet.

The average flash memory drive can hold about 30 MB of data, so that it acts like a highly portable and safe electronic notebook; it can of course hold not just e-documents but also mp3s, visual images, and even very small movies. They are so convenient that for some people they are replacing disks and CDs as their choice removable storage hardware.

More and more computers come with BIOS that will allow someone to configure the computer's USB port to act as a bootable device; this is used for functions such as booting up Windows through the flash drive. This flash drive functionality is extremely useful and it's what the computer techs use to try to see what might be ailing a seemingly dead computer and if they can fix it and retrieve at least some of the user's data.(The BIOS is the computer's ROM's algorithm for launching the OS and communicating with the various input devices such as the keyboard, mouse, and DVD drive).

Other removable flash memory devices include the flash PC Card, Compact Flash, and Smart Media.

Compact Flash is predominantly used in digital cameras.

Flash memory devices are made possible through the use of transistors as data storage devices. The transistors contained in a flash memory device can be induced via an electrical current to change their state from a '1' value to a '0' value and vice-versa, but when that current is shut off the new configuration of the transistors remains as it is until the next time they are stimulated.

Nearly all flash memory uses either the FAT-16 or FAT-32 file system (FAT stands for File Allocation Table; the numbers refer to the number of bits of data that can be coordinated by the memory).

FAT stores information about the physical location of each piece of every file in the flash memory and uncovers locations of unusable areas in the flash memory.