Over
`8,000
`Entrie
`
`with on ine updates
`available quarterty
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`Twitter Exhibit 1052
`Twitter, Inc. v. BlackBerry Ltd.
`Page 00001
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`

`

`PUBLISHED BY
`Microsoft Press
`A Division of Microsoft Corporation
`One Microsoft Way
`Redmond, Washington 98052-6399
`
`Copyright © 1999 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 Computer Dictionary. -- 4th ed.
`p. cm.
`Previous eds. published under title: Microsoft Press computer
`dictionary
`ISBN 0-7356-0615-3
`1. Computers Dictionaries. 2. Microcomputers
`I. Microsoft Press computer dictionary.
`QA76.15.M538 1999
`004' .03--dc21
`
`Dictionaries.
`
`99-20168
`CIP
`
`Printed and bound in the United States of America.
`
`123456789 MLML 432109
`
`Distributed in Canada by ITP Nelson, a division of Thomson Canada Limited.
`
`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. Visit our Web site at mspress.microsoft.com.
`
`Macintosh, Power Macintosh, QuickTime, and TrueType fonts are registered trademarks of Apple Computer,
`Inc. Kodak is a registered trademark of the Eastman Kodak Company. Intel is a registered trademark and Indeo
`is a trademark of Intel Corporation. Active Desktop, Active Directory, ActiveMovie, Active Platform, ActiveX,
`Authenticode, BackOffice, Directlnput, DirectX, Microsoft, Microsoft Press, MS-DOS, MSN, NetMeeting,
`NetShow, Visual Basic, Visual C++, Visual J++, WebTV, WebTV Network, Win32, Win32s, Windows,
`Windows NT, and XENIX are either registered trademarks or trademarks of Microsoft Corporation in the
`United States and/or other countries. PANTONE is a registered trademark of Pantone, Inc. Other product and
`company names mentioned herein may be the trademarks of their respective owners.
`
`The example companies, organizations, products, people, and events depicted herein are fictitious. No associa(cid:173)
`tion with any real company, organization, product, person, or event is intended or should be inferred.
`
`Acquisitions Editor: Christey Bahn
`Project Editor: Kim Fryer
`
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`

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`PSK
`
`pulse
`
`depend on server software to dynamically monitor
`the transmission. It can, however, play back only
`from the beginning of the file, rather than from any
`point, as can be the case with true streaming. See
`also stream.
`PSK n. See phase-shift keying.
`PSN n. Acronym for packet-switching network. See
`packet switching.
`PSTN n. See Public Switched Telephone Network.
`p-system n. An operating system based on a pseudo(cid:173)
`machine implemented in software. A program written
`for the p-system is more portable than one written for
`a machine-dependent operating system. See also
`UCSD p-System.
`P-type semiconductor n. Semiconductor material
`in which electrical conduction is carried by holes
`("vacancies" left by electrons). Whether a semicon(cid:173)
`ductor is N-type or P-type depends on the kind of
`dopant added during manufacture. A dopant with a
`shortage of electrons results in a P-type semicon(cid:173)
`ductor. Compare N-type semiconductor.
`pub n. See /pub.
`/pub n. Short for public. A directory in an anonymous
`FTP archive that is accessible by the public and that
`generally contains files available for free download.
`See also anonymous FTP.
`public directory n. A directory on an FTP server that
`is accessible by anonymous users for the purpose of
`retrieving or storing files . Often the directory is
`called /pub. See also anonymous FTP, FTP (defini(cid:173)
`tion I), FTP server, /pub.
`public domain n. The set of all creative works, such
`as books, music, or software, that are not covered by
`copyright or other property protection. Works in the
`public domain can be freely copied, modified, and
`otherwise used in any manner for any purpose. Much
`of the information, texts, and software on the Internet
`is in the public domain, but putting a copyrighted
`work on the Internet does not put it in the public do(cid:173)
`main. Compare proprietary.
`public-domain software n. A program donated for
`public use by its owner or developer and freely avail(cid:173)
`able for copying and distribution. Compare free soft(cid:173)
`ware, freeware, proprietary software, shareware.
`public files n. Files with no access restrictions.
`
`public folders n. The folders that are made accessible
`on a particular machine or by a particular user in a
`shared networking environment. Compare private
`folders .
`public key n. One of two keys in public key encryp(cid:173)
`tion. The user releases this key to the public, who can
`use it for encrypting messages to be sent to the user
`and for decrypting the user's digital signature. See
`also public key encryption. Compare private key.
`public key cryptography n. See public key encryption.
`public key encryption n. An asymmetric scheme that
`uses a pair of keys for encryption: the public key en(cid:173)
`crypts data, and a corresponding secret key decrypts
`it. For digital signatures, the process is reversed: the
`sender uses the secret key to create a unique elec(cid:173)
`tronic number that can be read by anyone possessing
`the corresponding public key, which verifies that the
`message is truly from the sender. See also private
`key, public key.
`public rights n. In the context of the Internet, the ex(cid:173)
`tent to which members of the public are permitted to
`use (and to place) information on the Internet under
`intellectual property law. See also fair use, public
`domain, public-domain software.
`Public Switched Telephone Network n. The public
`telephone system.
`puck n. A pointing device used with a graphics tablet.
`A puck, which is often used in engineering applica(cid:173)
`tions, is a mouselike device with buttons for selecting
`items or choosing commands and a clear plastic sec(cid:173)
`tion extending from one end with cross hairs printed
`on it. The intersection of the cross hairs on the puck
`points to a location on the graphics tablet, which in
`tum is mapped to a specific location on the screen.
`Because the puck's cross hairs are on a transparent
`surface, a user can easily trace a drawing by placing
`it between the graphics tablet and the puck and mov(cid:173)
`ing the cross hairs over the lines of the drawing. See
`also graphics tablet, stylus .
`pull vb. 1. The process of retrieving data from a net(cid:173)
`work server. Compare push (definition 2). 2. See pop.
`pull-down menu n. A menu that is pulled down from
`the menu bar and that remains available as long as
`the user holds it open. Compare drop-down menu.
`pulse n. A transient signal, usually brief and with a
`discrete onset and offset.
`
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`

`

`pulse amplitude modulation
`
`push
`
`pulse amplitude modulation n. A method of encod(cid:173)
`ing information in a signal by varying the amplitude
`of pulses. The unmodulated signal consists of a con(cid:173)
`tinuous train of pulses of constant frequency, dura(cid:173)
`tion, and amplitude. During modulation the pulse
`amplitudes are changed to reflect the information
`being encoded. See the illustration. Acronym: PAM.
`Compare pulse code modulation, pulse duration
`modulation, pulse position modulation.
`
`pulse position modulation n. A method of encoding
`information in a signal by varying the position of
`pulses. The unmodulated signal consists of a continu(cid:173)
`ous train of pulses of constant frequency, duration,
`and amplitude. During modulation the pulse posi(cid:173)
`tions are changed to reflect the information being
`encoded. See the illustration. Acronym: PPM. Com(cid:173)
`pare pulse amplitude modulation, pulse code modu(cid:173)
`lation, pulse duration modulation.
`
`Pulse amplitude modulation.
`pulse code modulation n. A method of encoding in(cid:173)
`formation in a signal by varying the amplitude of
`pulses. Unlike pulse amplitude modulation (PAM), in
`which pulse amplitude can vary continuously, pulse
`code modulation limits pulse amplitudes to several
`predefined values. Because the signal is discrete, or
`digital, rather than analog, pulse code modulation is
`more immune to noise than PAM. Acronym: PCM.
`Compare pulse amplitude modulation, pulse duration
`modulation, pulse position modulation.
`pulse dialing n. See rotary dialing.
`pulse duration modulation n. A method of encoding
`information in a signal by varying the duration of
`pulses. The unmodulated signal consists of a continu(cid:173)
`ous train of pulses of constant frequency, duration, and
`amplitude. During modulation, the pulse durations
`are changed to reflect the information being encoded.
`See the illustration. Acronym: PDM. Also called
`pulse length modulation, pulse width modulation.
`
`Pulse duration modulation.
`
`pulse length modulation n. See pulse duration modu(cid:173)
`lation.
`
`Pulse position modulation.
`pulse width modulation n. See pulse duration modu(cid:173)
`lation.
`punched card n. An outdated computer-input medium
`made of stiff paper that stores data bits in columns
`containing patterns of punched holes. The method for
`creating the patterns used for different byte values is
`called Hollerith coding. See also Hollerith tabulating/
`recording machine.
`punched-card reader n. See card reader.
`pure procedure n. Any procedure that modifies only
`data that is dynamically allocated (usually on the
`stack). A pure procedure cannot modify either global
`data or its own code. This restriction allows a pure
`procedure to be called simultaneously by separate
`tasks. See also reentrant code.
`purge vb. To eliminate old or unneeded information
`systematically; to clean up, as files .
`push 1 vb. 1. To add a new element to a stack, a data
`structure generally used to temporarily hold pieces of
`data being transferred or the partial result of an arith(cid:173)
`metic operation. See also stack. Compare pop. 2. In
`networks and the Internet, to send data or a program
`from a server to a client at the instigation of the
`. Compare pull (definition 1).
`server. See also push 2
`push2 n. A technology developed in relation to the
`World Wide Web, designed to provide end users with
`personalized Web access by having a site actively
`"push" requested information to the user's desktop,
`either automatically or at specified intervals. Push
`
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`

`

`put
`
`Python
`
`was developed as a means of relieving users from
`having to actively retrieve ("pull") information from
`the Web. It is not, as yet, especially popular.
`put vb. In programming, to write data, typically to a
`file ; in particular, to write a very small unit of data,
`such as a character.
`PVC n. Acronym for permanent virtual circuit. A per(cid:173)
`manent logical connection between two nodes on a
`packet-switching network. The PVC appears as a
`dedicated line to the nodes, but the data can be trans(cid:173)
`mitted on a common carrier. See also common carrier,
`
`node (definition 2), packet switching, virtual private
`network. Compare SVC.
`pwd n. Acronym for print working directory. The
`UNIX command for displaying the current directory.
`PWM Acronym for pulse width modulation. See
`pulse duration modulation.
`Python n. A portable, interpreted, object-oriented pro(cid:173)
`gramming language developed and freely distributed
`by its developer. Python runs on many platforms,
`including UNIX, Windows, OS/2, and Macintosh,
`and is used for writing TCP/IP applications.
`
`366
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