From (http://compactflash.org/info/cfinfo.htm CompactFlash Association):



'''CompactFlash''' is a very small removable mass storage device. First introduced in 1994 by (http://www.sandisk.com/ San Disk) Corporation, CF cards weigh a half ounce and are the size of a matchbook. They provide complete PCMCIA-ATA functionality and compatibility plus True IDE functionality compatible with ATA/ATAPI-4. At 43mm (1.7") x 36mm (1.4") x 3.3mm (0.13"), the device's thickness is less than one-half of a current [PCMCIA] Type II card. It is actually one-fourth the volume of a PCMCIA card. Compared to a 68-pin [PCMCIA] card, a CF card has 50 pins but still conforms to [PCMCIA] ATA specs. It can be easily slipped into a passive 68-pin Type II adapter card that fully meets PCMCIA electrical and mechanical interface specifications.



'''CF cards''' are also available for data storage using the Microdrive. CF I/O cards are available as modems, Ethernet, serial, digital phone cards, laser scanners, [bluetooth Bluetooth] wireless, etc.



CF first turned up as a storage medium in digital cameras and the like. Portable devices such as the iPaq use CF I/O cards for applications such as wireless networking.