Dell Precision 470 User Manual

Page 199

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Glossary: Dell Precision Workstation 470 and 670 Computers User's Guide

file:///T|/htdocs/systems/ws670/EN/ug_en/glossary.htm[3/20/2013 9:32:02 AM]

text editor — A program used to create and edit files that contain only text; for example, Windows Notepad uses a text

editor. Text editors do not usually provide word wrap or formatting functionality (the option to underline, change fonts, and so

on).

travel module — A plastic device designed to fit inside the module bay of a portable computer to reduce the weight of the

computer.

U

UPS — uninterruptible power supply — A backup power source used when the electrical power fails or drops to an

unacceptable voltage level. A UPS keeps a computer running for a limited amount of time when there is no electrical power.

UPS systems typically provide surge suppression and may also provide voltage regulation. Small UPS systems provide battery

power for a few minutes to enable you to shut down your computer.

USB — universal serial bus — A hardware interface for a low-speed device such as a USB-compatible keyboard, mouse,

joystick, scanner, set of speakers, printer, broadband devices (DSL and cable modems), imaging devices, or storage devices.

Devices are plugged directly into a 4-pin socket on your computer or into a multi-port hub that plugs into your computer.

USB devices can be connected and disconnected while the computer is turned on, and they can also be daisy-chained

together.

UTP — unshielded twisted pair — Describes a type of cable used in most telephone networks and some computer networks.

Pairs of unshielded wires are twisted to protect against electromagnetic interference, rather than relying on a metal sheath

around each pair of wires to protect against interference.

UXGA — ultra extended graphics array — A video standard for video cards and controllers that supports resolutions up to

1600 x 1200.

V

video controller — The circuitry on a video card or on the system board (in computers with an integrated video controller)

that provides the video capabilities—in combination with the monitor—for your computer.

video memory — Memory that consists of memory chips dedicated to video functions. Video memory is usually faster than

system memory. The amount of video memory installed primarily influences the number of colors that a program can display.

video mode — A mode that describes how text and graphics are displayed on a monitor. Graphics-based software, such as

Windows operating systems, displays in video modes that can be defined as x horizontal pixels by y vertical pixels by z colors.

Character-based software, such as text editors, displays in video modes that can be defined as x columns by y rows of

characters.

video resolution — See resolution.

virus — A program that is designed to inconvenience you or to destroy data stored on your computer. A virus program

moves from one computer to another through an infected disk, software downloaded from the Internet, or e-mail

attachments. When an infected program starts, its embedded virus also starts.

A common type of virus is a boot virus, which is stored in the boot sectors of a floppy disk. If the floppy disk is left in the

drive when the computer is shut down and then turned on, the computer is infected when it reads the boot sectors of the

floppy disk expecting to find the operating system. If the computer is infected, the boot virus may replicate itself onto all the

floppy disks that are read or written in that computer until the virus is eradicated.

V — volt — The measurement of electric potential or electromotive force. One V appears across a resistance of 1 ohm when a

current of 1 ampere flows through that resistance.

W

W — watt — The measurement of electrical power. One W is 1 ampere of current flowing at 1 volt.

WHr — watt-hour — A unit of measure commonly used to indicate the approximate capacity of a battery. For example, a 66-

WHr battery can supply 66 W of power for 1 hour or 33 W for 2 hours.

wallpaper — The background pattern or picture on the Windows desktop. Change your wallpaper through the Windows

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