24 Glossary
T
tpi
Tracks per inch.
track
Any of many concentric circular regions on a disk for storing
data. Tracks are divided into sectors. One measure of storage
density of a disk is tpi.
U
Ultra DMA
A protocol developed by Quantum Corporation and Intel that
supports burst mode data transfer rates of 33.3 MBps. This is
twice as fast as the previous disk drive standard for PCs, and is
necessary to take advantage of new, faster Ultra ATA disk
drives. The official name for the protocol is Ultra DMA/33.
USB
Universal Serial Bus. An external bus standard that supports
data transfer rates of 12 Mbps (12 million bits per second). A
single USB port can be used to connect up to 127 peripheral
devices, such as mice, modems, and keyboards. USB also
supports Plug-and-Play installation and hot plugging. It is
expected to eventually replace serial and parallel ports.
V
VESA
Video Electronics Standards Association. The source of a
SuperVGA standard used on many video boards.