vaporware Refers to either hardware or software that exist
only in the minds of the marketing department and never was offered
variable-Q equalizer See: proportional-Q
VCR (Video cassette Recorder) A device that can
record and playback video to and from video cassette tapes.
vector Mathematics. A quantity, such as velocity,
completely specified by a magnitude and a direction.
VESA ( Video Electronics Standards Association) A
trade organization formed mainly to propose and maintain standards
for the electronics industry. Widely known for the long list
of graphic display modes for video display devices.
VGA ( Video Graphics Adaptor )
Term for video cards used in personal computers and there outputs.
Includes standards for display mode of a computer display, in
particular the maximum number of colors and the maximum image
by pixels vertically
Videoconferencing Communication with remote users that
includes two way video and audio.
virus A self-replicating program released into a computer
system for mischievous reasons. Once triggered by some preprogrammed
event (often time or date related), the results vary from humorous
or annoying messages, to the destruction of data or whole operating
VLSI (very-large-scale integration) Refers to the
number of logic gates in an integrated circuit. By today's standards,
a VLSI device could contain up to one million gates.
Voice Tracking Electrical circuits that track the
movements of a speaker by measuring the sound arriving at the camera
from spoken voice.
volatile Refers to a memory device which loses any data
it contains when power is removed from the device. Examples would
include static and dynamic RAMs.
volt Abbr. E, also V. The International
System unit of electric potential and electromotive force, equal
to the difference of electric potential between two points on a
conducting wire carrying a constant current of one ampere when the
power dissipated between the points is one watt. [After Count
Volta, Count Alessandro (1745-1827) Italian physicist
who invented the battery (1800). The volt is named in his honor.
VOX ( Voice Activated Switch ) An electrical circuit that
controls one or more functions of the system based on the presence
of a voice at a particular microphone.
(virtual reality modeling language) A developing standard
for describing interactive 3D scenes delivered across the internet.
In short, VRML adds 3D data to the Web.
VU meter (volume units) The
term volume units was adopted to refer to a special meter
whose response closely related to the perceived loudness of the
audio signal. It is a voltmeter with standardized dB calibration
for measuring audio signal levels, and with attack and overshoot
(needle ballistics) optimized for broadcast and sound recording.
Jointly developed by Bell Labs, CBS and NBC, and put into use in
May, 1939, VU meter characteristics are defined by ANSI specification
"Volume Measurements of Electrical Speech aned Program waves,
" C16.5-1942 (original issue date; use latest). 0 VU is defined
to be a level of +4 dBu for an applied
sine wave. The VU meter has relatively slow response. It is driven
from a full-wave averaging circuit defined to reach 99% full-scale
deflection in 300 ms and overshoot not less than 1% and not more
than 1.5%. Since a VU meter is optimized for perceived loudness
it is not a good indicator of peak performance. Contrast with PPM.