Glossary 25
virus
Software that copies itself onto hard drives and diskettes
without user intervention, usually when a diskette is placed
into the drive of a computer. Viruses usually trigger a harmless
or destructive occurrence on the system, activated by some
preset condition. Viruses are frequently written with antisocial
intent.
VGA
Video Graphics Array. Graphics technology that supports up to
256 K colors and a graphics resolution of 640 by 480 pixels.
volatile memory
Storage media that loses its data when system power is turned
off. Standard memory and memory that you add to the system
are volatile memory. See nonvolatile memory.
VRAM
Video RAM. VRAM is special-purpose memory used by video
adapters. Unlike conventional RAM, VRAM can be accessed
by two different devices simultaneously. This enables a video
adapter to access the VRAM for screen updates at the same
time that the CPU provides new data. VRAM yields better
graphics performance but is more expensive than normal
RAM. A special type of VRAM, called Windows RAM
(WRAM), yields even better performance than conventional
VRAM. See SGRAM and WRAM.
W
warm boot
Process of resetting the computer without turning off the power
through keyboard input (pressing
Ctrl
,
Alt
, and
Del
keys
simultaneously) or the reset button. The system returns to an
initial or arbitrarily selected condition.
