User's Manual

Glossary 199
• LowerThresholdNon-critical
• LowerThresholdCritical
• LowerThresholdFatal
time-out
A specified period of system inactivity that must occur
before an energy conservation feature is activated.
tpi
Abbreviation for tracks per inch.
TQFP
Acronym for thin quad flat pack.
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 computer without starting
any TSR programs.
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