User's Manual

Glossary 207
UART
Acronym for universal asynchronous receiver
transmitter, the electronic circuit that makes up the
serial port.
UDP
Acronym for user datagram protocol.
UL
Abbreviation for Underwriters Laboratories.
UMB
Abbreviation for upper memory blocks.
unicode
A fixed width, 16-bit world wide character encoding,
developed and maintained by the Unicode
Consortium.
upper memory area
The 384 KB of RAM located between 640 KB and
1 MB. If the computer has an Intel386 or higher
microprocessor, a utility called a
memory manager can
create UMBs in the upper memory area, in which you
can load device drivers and memory-resident programs.
UPS
Abbreviation for uninterruptible power supply.
A battery-powered unit that automatically supplies
power to your computer in the event of an
electrical failure.
USB
Abbreviation for Universal Serial Bus. A USB connector
provides a single connection point for multiple USB-
compliant devices, such as mice, keyboards, printers,
and computer speakers. USB devices can also be
connected and disconnected while the system is running.
utility
A program used to manage system resources—
memory, disk drives, or printers, for example.
UTP
Abbreviation for unshielded twisted pair.
UUID
Acronym for Universal Unique Identification.
V
Abbreviation for volt(s).
VAC
Abbreviation for volt(s) alternating current.
varbind
An algorithm used to assign an object identifier or OID.
The varbind gives rules for arriving at the decimal prefix
that uniquely identifies an enterprise, as well as the
formula for specifying a unique identifier for the
objects defined in that enterprise's MIB.
variable
A component of a managed object. A temperature
probe, for example, has a variable to describe its
capabilities, its health or status, and certain indexes
that you can use to help you in locating the right
temperature probe.
VCCI
Abbreviation for Voluntary Control Council for
Interference.
VCR
Abbreviation for video cassette recorder.
VDC
Abbreviation for volt(s) direct current.
VESA
Acronym for Video Electronics Standards Association.
VGA
Abbreviation for video graphics array. VGA and SVGA are
video standards for video adapters with greater resolution
and color display capabilities than previous standards. To
display a program at a specific resolution, you must install
the appropriate video drivers and your monitor must
support the resolution. Similarly, the number of colors
that a program can display depends on the capabilities of
the monitor, the video driver, and the amount of video
memory installed for the video adapter.