Users Guide

Glossary 141
TSR
Abbreviation for terminate-and-stay-resident. A TSR
program runs "in the background." Most TSR programs
implement a predefined key combination (sometimes
referred to as a hot key) that allows you to activate the
TSR program's interface while running another
program. When you finish using the TSR program, you
can return to the other application program and leave
the TSR program resident in memory for later use.
TSR programs can sometimes cause memory conflicts.
When troubleshooting, rule out the possibility of such
a conflict by rebooting your system without starting any
TSR programs.
UART
Acronym for universal asynchronous receiver
transmitter, the electronic circuit that makes up the
serial port.
UDP
Abbreviation 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 system 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 system in the event of an
electrical failure.
URL
Abbreviation for Uniform Resource Locator (formerly
Universal Resource Locator).
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.
utility partition
A bootable partition on the hard drive that provides
utilities and diagnostics for your hardware and
software. When activated, the partition boots and
provides an executable environment for the
partition's utilities.
UTP
Abbreviation for unshielded twisted pair.
UUID
Abbreviation 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 (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.