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Toshiba PORTEGE M400 User Manual

Page 243

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User’s Manual

Glossary--6

Glossary

D

data: Information that is factual, measurable or statistical that a computer

can process, store, or retrieve.

data bits: A data communications parameter controlling the number of bits

(binary digits) used to make up a byte. If data bits = 7 the computer

can generate 128 unique characters. If data bits = 8 the computer

can generate 256 unique characters.

DC: Direct Current. Electric current that flows in one direction. This type of

power is usually supplied by batteries.

default: The parameter value automatically selected by the system when

you or the program do not provide instructions. Also called a preset

value.

delete: To remove data from a disk or other data storage device.

Synonymous with erase.

device driver: A program that controls communication between a specific

peripheral device and the computer. The CONFIG.SYS file contains

device drivers that MS-DOS loads when you turn the computer on.

dialog box: A window that accepts user input to make system settings or

record other information.

disk drive: The device that randomly accesses information on a disk and

copies it to the computer’s memory. It also writes data from memory

to the disk. To accomplish these tasks, the unit physically rotates the

disk at high speed past a read-write head.

disk storage: Storing data on magnetic disk. Data is arranged on

concentric tracks much like a phonograph record.

display: A CRT, LCD, or other image producing device used to view

computer output.

documentation: The set of manuals and/or other instructions written for

the users of a computer system or application. Computer system

documentation typically includes procedural and tutorial information

as well as system functions.

DOS: Disk Operating System. See operating system.
driver: A software program, generally part of the operating system, that

controls a specific piece of hardware (frequently a peripheral device

such as a printer or mouse).

DVD-R (+R, -R): A Digital Versatile Disc-Recordable disk can be written

once and read many times. The DVD-R drive uses a laser to read

data from the disc.

DVD-RAM: A Digital Versatile Disc-Random Access Memory is a high-

capacity, high performance disc that lets you store large volumes of

data. The DVD-ROM drive uses a laser to read data from the disc.

DVD-R DL: A disc having two layers on one side with the DVD-R storage

capacity about 1.8 times larger than before. The DVD-RW drive

uses a laser to read data from the disc.

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