z I
`
`
`
` - MICROSOFT PRESS®
`
`COMPUTER
`DICTIONARY
` 0821 07021 5
`
`THE COMPREHENSIVE
`
`STANDARD FOR
`
`BUSINESS, SCHOOL,
`
`LIBRARY, AND HOME
`
`PRESS
`
`Google 1024
`IPR2018—01079
`
`US. Patent No. 8,213,970
`
`0001
`
`Google 1024
`IPR2018-01079
`U.S. Patent No. 8,213,970
`
`

`

`PUBLISHED BY
`Microsoft Press
`A Division of Microsoft Corporation
`One Microsoft Way
`Redmond, Washington 98052—6399
`Copyright © 1991 by Microsoft Press, a division of 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 : the comprehensive standard for
`business, school, library, and home.
`p.
`cm.
`ISBN 1-55615—251-0
`l. Computers~Dictionaries.
`1. Microsoft Press.
`QA76.15.M54
`1991
`004.16'03-—dc20
`
`2. Microcomputers—-Dictionaries.
`
`91-9904CIP
`
`Printed and bound in the United States of America.
`23456789 MLML 654321
`Distributed to the book trade in Canada by Macmillan of Canada, a division
`of Canada Publishing Corporation.
`Distributed to the book trade outside the United States and Canada by
`Penguin Books Ltd.
`Penguin Books Ltd., Harmondsworth, Middlesex, England
`Penguin Books Australia Ltd., Ringwood, Victoria, Australia
`Penguin Books NZ. Ltd., 182—190 Wairau Road, Auckland 10, New Zealand
`British Cataloging-in—Publication Data available.
`
`Acquisitions Editor: Marjorie Schlaikjer
`Project Editor: Mary Ann Jones
`Technical Editors: David Rygmyr, Jeff Hinsch, Mary DeJong, Dail Magee, Jr.
`Manuscript Editor: Pamela Beason
`Copy Editor: Alice Copp Smith
`
`
`
`0002
`
`

`

`
`
`pack To store information in a more compact form.
`Packing eliminates unnecessary spaces and other
`such characters and may use other special methods
`of compressing data as well. It is used by some pro-
`grams to minimize storage requirements. Although
`packed data is not necessarily readable by humans
`in its compressed form,
`it can be unpacked and
`restored to its original appearance. See also data
`compression.
`package A computer application consisting of one
`or more programs created to perform a particular
`type of work—for example, an accounting package
`or a spreadsheet package. Software packages are
`
`designed to satisfy the needs of more than one or—
`ganization; they are generally considered the same
`as “off-the-shelf” or “canned” programs.
`packaged software A software program sold
`through a retail distributor as opposed to custom
`software. Compare canned software.
`packed decimal A method of encoding decimal
`numbers in binary form that maximizes storage
`space by using each byte to represent two decimal
`digits. For example, in binary form, the 1 in the
`decimal number 12 is represented as 000], and the
`2 is represented as 0010. If one byte is allotted to
`each decimal digit, decimal I2 is written
`
`00000001 00000010
`
`with extraneous 0’s filling in the leftmost four
`superfluous bit positions in each byte.
`In the
`packed decimal method, however, where each
`byte represents two digits,
`the same number is
`written
`
`00010010
`
`thereby saving one full byte of storage. When
`signed decimal numbers are stored in packed deci—
`mal format, the sign appears in the rightmost four
`bits of the rightmost (least significant) byte.
`packet In general usage, a unit of information trans-
`mitted as a whole from one device to another on a
`
`network. In packet—switching networks, a packet is
`defined more specifically as a transmission unit of
`fixed maximum size that consists of binary digits
`representing both data and a header containing an
`identification number, source and destination ad—
`dresses, and, sometimes, error-control data. See
`also packet switching.
`packet switching A message-delivery technique in
`which small units of information (packets) are
`relayed through stations in a computer network
`along the best route currently available between
`the source and the destination. A packet—switching
`network handles information in small units, break-
`ing long messages into multiple packets before
`routing. Although each packet may travel along a
`different path, and the packets composing a mes-
`sage may arrive at different times or out of se—
`quence,
`the receiving computer reassembles the
`original message. This repackaging is called packet
`assembly and disassembly (PAD). Packet-switching
`networks are considered to be fast and efficient. To
`
`manage the tasks of routing traffic and assembling/
`disassembling packets,
`such networks
`require
`some “intelligence” from the computers and soft—
`ware that control delivery. Standards for packet
`switching on networks are documented in the
`CCITT recommendation X25.
`
`packing density The number of storage units per
`length or area of a storage device. Bits per inch is
`
`255
`
`
`
`0003
`
`

`

`
`
`pad character
`
`
`
`page-description language
`
`one measure of packing density.
`pad character In data input and storage, an extra
`character inserted as “filler” to use up surplus
`space in a predefined block of a specified length,
`such as a fixed—length field.
`padding In data storage, the addition of one or
`more bits (usually zeros) to a block of data in order
`to fill it, to force the actual data bits into a certain
`position, or to prevent the data from duplicating a
`bit pattern that has an established meaning, such as
`an embedded command.
`paddle An early type of input device often used
`with computer games, especially for side—to—side or
`up—and-down movements of an on—screen object.
`See the illustration. A paddle is less sophisticated
`than a joystick because it permits the user to
`specify movement along a single axis only, by turn-
`ing a dial. The paddle, first known as the paddle
`controller, got its name because its most popular
`use was to control the on-screen paddle bars in the
`simple early video games.
`
`
`
`Paddk.
`
`paddle switch Any switch that has a wide handle.
`The large on/off switch on IBM personal computers
`is one type of paddle switch.
`page A fixed-size block of memory. When used in
`the context of a paging memory system, a page is a
`block of memory whose physical address can be
`changed via mapping hardware. A page is typically
`associated with virtual memory hardware, although
`the 16-kilobyte (KB) blocks mapped using the Ex—
`panded Memory Specification (EMS) are also called
`pages. In the memory management unit (MMU) of
`the 80586 and 80486, a page is 4 KB. In Motorola
`systems,
`the page size is configurable between
`256 bytes and 32 KB. See also Expanded Memory
`Specification, memory management unit, virtual
`memory.
`
`In computer graphics, a portion of display mem—
`
`ory that contains one complete full—screen image;
`the internal
`representation of a
`screenful of
`information.
`
`page break The point at which the flow of text in a
`document moves to the top of a new page. Most
`word—processing programs create an automatic
`page break when the material on the page reaches
`a specified maximum depth. By contrast, a “hard”
`or “manual” page break is a command or code in—
`serted by the user to force a page break at a specific
`place in the text. In older word processors, a page
`break can be created by the insertion of a form—
`feed character. See also form feed.
`paged address In the 80386 and i486 paged—
`memory architecture,
`an address
`in memory
`created by combining the processes of segment
`translation and page translation.
`In the paged-
`memory scheme, which requires that the micro—
`processor’s paging feature be enabled, logical ad—
`dresses are transformed into physical addresses
`(actual locations in physical memory) in two steps:
`segment translation and page translation. The first
`step, segment translation, converts a logical ad-
`dress (consisting of an segment selector and a seg-
`ment offset) to a linear address—an address that
`refers indirectly to a physical address. After the
`linear address is obtained,
`the microprocessors
`
`paging hardware converts the linear address to a
`physical address by specifying a page table (an ar—
`ray of 52—bit page specifiers), a page (a 4—KB unit of
`contiguous addresses within physical memory)
`within that table, and an offset within that page.
`This information, called a paged address, collec—
`tively refers to a physical address.
`page-description language Abbreviated PDL. A
`programming language, such as PostScript, that is
`used to describe output to a printer or a display de—
`vice, which then uses the instructions from the
`page—description language to construct text and
`graphics to create the required page image. PDLs
`are like other computer languages, with logical pro—
`gram flow allowing for sophisticated manipulation
`of the output. A page—description language, like a
`blueprint, sets out specifications (as for fonts and
`type sizes) but leaves the work of drawing charac—
`ters and graphics to the output device itself. Be—
`
`
`
`254
`
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