Users Guide

Glossary 237
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.