Another type of memory you may see mentioned in the trade press these days is flash memory. Flash memory is a hybrid technology that works somewhat like RAM and somewhat like a hard disk. It stores data in memory cells like RAM; but unlike RAM, the data stays in memory after the power is turned off.
Because flash memory has a limited life span and storage space, and must be erased in blocks of data rather than single bytes like RAM, it will never replace RAM. But compared with hard drives, flash memory has several advantages. It has no moving parts, so it has a higher tolerance for shock, vibration, extreme temperatures and harsh environments. Flash memory cards are also smaller and faster than hard drives.
Thanks to these characteristics, flash memory cards are being used as portable hard drives in rugged situations. They're also used in digital cameras, cellular phones, audio recorders and scanners to store images and voice data; in networking devices to store microcodes and instructions for transferring data; and in printers and print servers to hold fonts or frequently used graphics.
Cheryl J. Goldberg is a former editor of PC Magazine and has reported on the computer industry for more than 14 years. Write to her in care of Entrepreneur, 2392 Morse Ave., Irvine, CA 92614. You can also reach her via CompuServe at 70641,3632.