Quick Reference Guide

362 Glossary
virtual memory
A method for increasing addressable RAM by using the hard drive. For example,
in a system with 16 MB of RAM and 16 MB of virtual memory set up on the hard
drive, the operating system would manage the system as though it had 32 MB of
physical RAM.
virus
A self-starting program designed to inconvenience you. Virus programs have been
known to corrupt the files stored on a hard drive or to replicate themselves until
a computer system or network runs out of memory. The most common way that
virus programs move from one system to another is by infected diskettes, from
which they copy themselves to the hard drive. To guard against virus programs,
you should do the following:
• Periodically run a virus-checking utility on your system's hard drive
• Always run a virus-checking utility on any diskettes (including commercially sold
software) before using them
VLSI
Abbreviation for very-large-scale integration.
VLVESA
Acronym for very low voltage enterprise system architecture.
VNC
Abbreviation for virtual network computing.
vpp
Abbreviation for peak-point voltage.
VRAM
Acronym for video random-access memory. Some video adapters use VRAM chips
(or a combination of VRAM and DRAM) to improve video performance. VRAM
is dual-ported, allowing the video adapter to update the screen and receive new
image data at the same time.
VT-100
Abbreviation for Video Terminal 100, which is used by the most common terminal
emulation programs.