Quick Reference Guide

304 Glossary
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.
TSOP
Abbreviation for thin small outline package. A very
thin, plastic, rectangular surface mount chip package
with gull-wing pins on its two short sides.
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.
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.
UTC
Abbreviation for Universal Coordinated Time. See GMT.
UTP
Abbreviation for unshielded twisted pair.
UUID
Abbreviation for Universal Unique Identification.
V
Abbreviation for volt(s).
VAC
Abbreviation for volt(s) alternating current.
Validation
Process of checking a command.