:crosoft
`
`l.IhiwsNT'
`
`n T
`
`The Ultimate Computer Reference
`
`witter-Google Exhibit 1010
`
`Twitter-Google Exhibit 1010
`
`

`

` Mimmfi
`
`gigiiww
`
`
`Cpllflbllflbl‘
`Iblcmmalry
`
`Third Edition
`
`Microsofthress
`
`
`
`

`

`
`
`PUBLISHED BY
`Microsoft Press
`A Division of Microsoft Corporation
`One Microsoft Way
`Redmond, Washington 98052-6399
`
`Copyright © 1997 by Microsoft Corporation
`
`All rights reserved. No part of the contents of this book may be reproduced or transmitted
`in any form or by any means without the written permission of the publisher.
`
`Library of Congress Cataloging—in-Publication Data
`Microsoft Press Computer Dictionary. -— 3rd ed.
`p.
`cm.
`ISBN 1-57231-446-X
`
`l. Computers--Dictionaries.
`I. Microsoft Press.
`
`2. Microcomputers--Dictionaries.
`
`QA76.15.M54 1997
`004'.03--dc2l
`
`97-15489
`CIP
`
`Printed and bound in the United States of America.
`
`23456789 QMQM 210987
`
`Distributed to the book trade in Canada by Macmillan of Canada. a division of Canada Publishing
`Corporation.
`
`A CIP catalogue record for this book is available from the British Library.
`
`Microsoft Press books are available through booksellers and distributors worldwide. For further
`information about international editions, contact your local Microsoft Corporation office. Or contact
`Microsoft Press International directly at fax (425) 936-7329.
`
`Macintosh, Power Macintosh. QuickTime, and TrueType are registered trademarks of Apple Computer.
`Inc. Intel is a registered trademark of Intel Corporation. Directlnput, DirectX. Microsoft. Microsoft
`Press. MS-DOS, Visual Basic. Visual C++, Win32. Win325. Windows. Windows NT. and XENIX are
`registered trademarks and ActiveMovie, ActiveX. and Visual J++ are trademarks of Microsoft
`Corporation. Java is a trademark of Sun Microsystems, Inc. Other product and company names
`mentioned herein may be the trademarks of their respective owners.
`
`Acquisitions Editor: Kim Fryer
`Project Editor: Maureen Williams Zimmerman. Anne Taussig
`Technical Editors: Dail Magee Jr., Gary Nelson. Jean Ross. Jim Fuchs. John Conrow. Kurt Meyer,
`Robert Lyon. Roslyn Lutsch
`
`

`

`
`
`density disks increased that capacity to 360 KB.
`Double—density disks use modified frequency
`modulation encoding for storing data. See also
`floppy disk, microfloppy disk, modified frequency
`modulation encoding. Compare high—density disk.
`double-dereference \ da‘ bl—dé-ref’er-ans,
`-dé—
`ref’rans\
`1219. To dereference a pointer that
`is
`pointed to by another pointer; in other words, to
`aCCess the information pointed to by a handle. See
`also dereference, handle (definition 1), pointer
`(definition 1).
`
`double-precision \da‘bl-pra—sizh’am adj. Of,
`pertaining to, or characteristic of a number stored
`
`(two words—typically 8
`in twice the amount
`bytes) of computer memory that is required for
`storing a less precise (single—precision) number.
`Double-precision numbers are commonly handled
`by a computer in floating-point
`form. See also
`floating-point number. Compare single-precision.
`double-sided disk \da‘bl-si—ded
`disk’\
`71.
`A
`floppy disk that can hold data on both its top and
`bottom surfaces.
`
`21. On an impact
`double-strike \da’bl-strik‘\
`printer, such as a daisy-wheel printer, the process
`of printing twice over a word, producing text that
`appears darker and heavier, or bolder, than it nor-
`mally appears. On dot—matrix printers, double
`striking with a slight offset can be used to fill in the
`space between the dots, producing smoother and
`darker characters.
`
`double word \da‘bl ward’\ n. A unit of data con-
`
`sisting of two contiguous words (connected bytes,
`not text) that are handled together by a computer’s
`microprocessor.
`71. A series
`doubly linked list \da‘blé lénkd list’\
`of nodes (items representing discrete segments of
`information) in which each node refers to both the
`next node and the preceding node. Because of
`these two—way references, a doubly linked list can
`be traversed both forward and backward, rather
`than in a forward direction only, as with a singly
`linked list.
`
`down \doun\ adj. Not functioning, in reference to
`computers, printers, communications lines on net—
`works, and other such hardware.
`downlink \doun’lénk\
`n. The transmission of
`data from a communications satellite to an earth
`station.
`
`download \doun’lod\ 12b. 1. in communications, to
`transfer a copy of a file from a remote computer to
`the requesting computer by means of a modem or
`network. 2. To send a block of data, such as a Post-
`Script file, to a dependent device, such as a PostScript
`printer. Compare upload.
`downloadable font \doun’lo-da-bl font‘\ 7]. A set
`of characters stored on disk and sent
`(down—
`loaded) to a printer’s memory when needed for
`printing a document. Downloadable fonts are
`most commonly used with laser printers and other
`page printers, although many dot-matrix printers
`can accept some of them. Also called soft font.
`
`downsizing \doun’si‘zéng\ n. In computing, the
`practice of moving from larger computer systems.
`such as mainframes and minicomputers, to smaller
`systems in an organization, generally to save costs
`and to update to newer software. The smaller sys-
`tems are usually client/server systems composed of
`a combination of PCs, workstations, and some leg-
`acy system such as a mainframe. connected in one
`or more local area networks or wide area networks.
`
`See also client/server architecture, legacy system.
`downstream \doun-strém’\ n. The direction in
`which a news feed for a newsgroup is passed from
`one news server to the next. See also news feed.
`news server, newsgroup.
`
`downtime \doun’tim\ 72. The amount or percent-
`age of time a computer system or associated hard-
`ware remains nonfunctional. Although downtime
`can occur because hardware fails unexpectedly, it
`can also be a scheduled event, as when a network
`is shut down to allow time for maintenance.
`kam—
`downward compatibility \doun’ward
`pat‘a-bil\a—té\ n. The capability of source code or
`programs developed on a more advanced system
`or compiler version to be executed or compiled by
`a less advanced (older) version. Compare upward-
`compatible.
`DP \D-P’\ n. See data processing.
`dpi \DiP-I’\ 11. See dots per inch.
`DPMA \D‘P-M—A’\ n. Acronym for Data Process—
`ing Management Association. A trade organization
`of information systems (15) professionals. DPMA
`was founded in 1951 as the National Machine
`Accountants Association.
`
`DPMI \D‘P-M—I’\ n. Acronym for DOS Protected
`Mode Interface. A software interface, originally
`
`

`

`Pentium
`
`Pentium \pen’té—um\ n. A microprocessor intro—
`duced by Intel Corporation in March 1995 as the
`successor to the i486. The Pentium is a superscalar,
`CISC-based microprocessor containing 3.3 million
`transistors. The Pentium has a 52-bit address bus.
`
`a 64—bit data bus, a built-in floating—point unit and
`memory management unit, two built-in 8-KB L1
`caches, and a System Management Mode (SMM).
`which provides the microprocessor with the ability
`to slow or halt some system components when the
`system is idle or performing non—CPU-intensive
`tasks. thereby lessening power consumption. The
`Pentium also employs branch prediction, resulting
`in faster system performance. In addition. the Pen—
`tium has some built-in features to ensure data
`
`integrity, and it supports functional redundancy
`checking (FRC). See also branch prediction. CISC.
`functional
`redundancy checking,
`i486DX,
`L1
`cache, microprocessor, PS. superscalar. Compare
`Pentium Pro (definition 1),
`
`71. 1. Intel's ISO—
`Pentium Pro \pen‘te-um pro’\
`200 MHZ family of 52—bit processors. released in
`November 1995. The Pentium Pro is considered
`
`the next generation of processors in the 8086 fam—
`ily, following the Pentium. and is designed for run—
`ning 32-bit operating systems and applications. See
`also 32—bit application. 52-bit operating system,
`8086. microprocessor, Pentium. 2. A PC that has a
`Pentium Pro processor.
`Pentium upgradable \pen‘té-um up—grz‘t’da—bl\
`n. 1. An i486 motherboard capable of being
`adapted to run a Pentium-class processor. See also
`i486DX, microprocessor, motherboard, Pentium.
`2. A 486 PC that can be upgraded to Pentium
`class by adding a Pentium processor. See also
`i486DX.
`
`12. Short
`perfboard \parf’bord\
`fiber board. See breadboard.
`
`for perforated
`
`performance monitor \par—for’mans mon‘a—tafl
`n. A process or program that appraises and
`records status information about various system
`devices and other processes.
`period \per’e-de n. The length of time required
`for an oscillation to complete one full cycle. For an
`oscillating electrical signal, the period is the time
`between waveform repetitions.
`If f is
`the fre—
`quency of oscillation in hertz, and ris the period
`in seconds. then 1‘= 1/] See the illustration.
`
`Period. The period of an oscillating signal
`
`a
`computing.
`In
`iz.
`peripheral \par—if’ar-al\
`device. such as a disk drive, printer, modem. or
`joystick. that is connected to a computer and is
`controlled by the computer‘s microprocessor. Ab:-
`called peripheral device. See also console.
`Peripheral Component Interconnect \ par-if er-
`al kam—poinent
`in‘tar—ka—nekt’\
`)1. See PCI local
`bus.
`
`71. See
`
`permanent stora; Amplitude
`fields that encode data in the media tend to fade
`
`dé—vis’\
`
`peripheral device \par—if’ar-al
`peripheral.
`peripheral power supply \par—if ar—al pou’er SU‘
`plT\ n. An auxiliary source of electricity used by
`a computer or a device as a backup in case of a
`power failure. Acronym: PPS (P‘P-S').
`Perl \parl\ n. Acronym for Practical Extraction and
`Report Language. An interpreted language, based
`on C and several UNIX utilities. Perl has powerful
`string—handling features for extracting information
`from text files. Perl can assemble a string and send
`it to the shell as a command; hence, it is often used
`
`for system administration tasks. A program in Perl
`is known as a script. Perl was devised by Larry
`Wall at NASA‘s ~let Propulsion Laboratory.
`n. A
`permanent storage \par‘ma—nant
`stor’9j\
`recording medium that retains the data recorded
`on it for long periods of time without power. Ink
`on paper is by far the most Widely used permanent
`storage. but data can be transferred from paper to
`a computer only with difficulty. Typically. some
`form of magnetic medium. such as floppy disk or
`tape.
`is preferable. Magnetic media are generally
`accepted as permanent. even though the magnetic
`
`

`

`scripting language
`
`SCSI ID
`
`The instructions usually use the rules and syntax
`of the application or utility. See also macro.
`n. A
`scripting language \skrip’téng 1ang‘waj\
`simple programming language designed to per-
`form special or limited tasks. sometimes associated
`with a particular application or function. An exam—
`ple of a scripting language is Perl. See also Perl,
`script.
`scroll \skr61\
`
`11b. To move a document or other
`
`data in a window in order to view a particular por-
`tion of the document. Scrolling may be controlled
`by the mouse, arrow keys, or other keys on the
`keyboard. See also scroll bar.
`scroll arrow \skrél’ ar‘6\
`11. See scroll bar.
`
`72. In some graphical user
`scroll bar \skrol’ biir\
`interfaces, :1 vertical or horizontal bar at the side or
`bottom of a display area that can be used with a
`mouse for moving around in that area. Scroll bars
`often have four active areas: two scroll arrows for
`
`moving line by line, a sliding scroll box for moving
`to an arbitrary location in the display area. and
`gray areas for moving in increments of one win—
`dow at a time. See the illustration.
`scroll box \skrél’ boks\ 71. See elevator.
`
`12. On the IBM
`Scroll Lock key \skroi’ lok ke‘\
`PC/XT and AT and compatible keyboards. a key on
`the top row of the numeric keypad that controls
`the effect of the cursor control keys and sometimes
`prevents
`the screen from scrolling. On the
`enhanced and Macintosh keyboards, this key is to
`the right of the function keys on the top row. Many
`modern applications ignore the Scroll Lock setting.
`SCSI \skuz’é, S‘C—S—l’\ n. Acronym for Small Corn—
`puter System Interface, a standard high-speed par—
`allel interface defined by the X5T9.2 committee of
`the American National Standards Institute (ANSI).
`
`A SCSI interface is used to connect microcomput-
`ers to SCSI peripheral devices, such as many hard
`disks and printers, and to other computers and
`local area networks. Compare ESDI, IDE.
`SCSI-1 \skuz‘é—wan’, S—C—S—I‘wan’\
`17. See SCSI.
`SCSI-2 \skuz‘é-tOT)’,
`S-C-S—Iltd—OW n. An
`en—
`hanced ANSI standard for SCSI (Small Computer
`System Interface) buses. Compared with the origi—
`nal SCSI standard (now called SCSI—1). which can
`transfer data 8 bits at a time at up to 5 MB per sec-
`ond, SCSI—2 offers increased data width. increased
`speed, or both. A SCSI-2 .disk drive or host
`adapter can work with SCSI-1 equipment at the
`older equipment’s maximum speed. See also Fast
`SCSI, Fast/Wide SCSI, SCSI, Wide SCSI. Compare
`UltraSCSI.
`
`SCSI bus \skuze bus, S‘C—S-I’\ n. A parallel bus
`that carries data and control signals from SCSI
`devices to a SCSI controller. See also bus, control—
`ler, SCSI device.
`SCSI chain \skuz’e chan‘, S‘C-S-I’\ n. A set of
`devices on a SCSI bus. Each device (except the
`host adapter and the last device) is connected to
`two other devices by two cables, forming a daisy
`chain. See also daisy chain, SCSI.
`SCSI connector \skuz’e ka-nek‘tar, S‘C—S-I’\ n. A
`cable connector used to connect a SCSI device to
`
`a SCSI bus. See the illustration on the next page.
`See also bus, connector (definition 1), SCSI device.
`SCSI device \skuz’é da—vis‘, S‘C-S-I’\ n. A periph—
`eral device
`that uses
`the SCSI
`standard to
`
`exchange data and control signals with a com-
`puter’s CPU. See also peripheral, SCSI.
`SCSI ID \skuz’é I-D’ S—C-S—I’\ n. The unique iden-
`tity of a SCSI device. Each device connected to a
`SCSI bus must have a different SCSI ID. A maxi—
`
`Scroll bar.
`
`Q My Computer
`Q Network Neighbor...
`1 Q Inbox
`i.- fiRecycle Bin
`" a The Internet
`The Microsolt Net...
`C: My Briefcase
`
`System Fold!
`System Folds
`
`System Folds
`File Folder
`
`Scroll bars
`
`