Compact Flash is a small, removable mass storage device. First introduced in 1994, compact flash (CF) cards weigh one-half ounce and are the size of a matchbook. They provide complete PCMCIA-ATA functionality and compatibility. There are Type 1 and Type 2 CF devices. Type 2 is the thicker one (5mm) and will not fit into slots designed exclusively for the thinner type 1 (3mm) flash. So, if you are buying more CF, be sure what type you are buying.
ATA refers the "AT Attachment" disk interface which has gone through many generations. The ATA standards are maintained by T13.
The connector used with CF is similar to the PCMCIA Card connector, but with 50 pins. Because CF has the ATA functionality, the PCMCIA adapter can be very simple (essentially a passive pass-through) device and no interface processing is needed.
Because CF contains EEPROM, there is a finite life because EEPROM can only be cycled so many times before it wears out. Thus, CF should not be used in applications where a huge number of memory changes would be done such as a continuously cycling cache.
There are USB devices that will let you plug your CF into them so that you in effect have a external USB hard drive with capacity of that CF card. This can be a portable convenient way of transferring small files between systems.
Galbraith Compact Flash Database has reviews, commentary, and up-to-date facts on the most current CF.
