0001 IBG 1024
`CBM of U.S. Pat. No. 7,533,056
`
`

`
`This book is available at a special discount when ordered in bulk
`quantities. For information, contact Special Sales Department,
`AMACOM, a division of American Management Association,
`135 West 50th Street, New York, NY 10020.
`
`This publication is designed to provide accurate and authoritative information in
`regard to the subject matter covered. It is sold with the understanding that the
`publisher is not engaged in rendering legal, accounting, or other professional service.
`If legal advice or other expert assistance is required, the services of a competent
`professional person should be sought.
`
`Library of Congress Cataloging-in-Publication Data
`
`the complete illustrated desk reference /
`
`Freedman, Alan, 1942-
`The computer glossary :
`Alan Freedman. —— 5th ed.
`p.
`cm.
`ISBN U—8144—5020-2 (hard). —~
`1. Cnmpurers~—D1ctionaries.
`—Dicrionaries.
`I. Title.
`OA7G.15.F734
`1991
`004‘ .03~-dc20
`
`~
`
`ISBN 0—8l44—7749-6 (pbk.)
`2. Electronic data processing-
`
`904269CIP
`
`© 1991, 1989, 1983, 1981
`The Computer Language Company Inc.
`All rights reserved.
`Printed in the United States of America.
`
`Previous editions were published by Prentice-Hall and
`The Computer Language Company Inc.
`
`This publication may not be reproduced, stored in a retrieval system,
`or transmitted in whole or in part, in any form or by any means, electronic,
`mechanical, photocopying, recording, or otherwise, without the prior written
`permission of AMACOM, a division of American Management Association,
`135 West 50 Street, New York, NY 10020.
`
`Printing number.
`
`10987654321
`
`
`
`0002
`0002
`
`

`
`
`
`DECsystem
`(1) A series of RlSC—based, 32-bit computers from Digital Equipment
`Corporation that run under ULTRIX. Introduced in 1989, the 5400 model is a
`Q-bus system; the 5800 model uses the XMI bus.
`
`(2) A series of mainframes from Digital that were introduced from 1974 through
`1980 and were the successor to the 36-bit PDP—1O computers.
`
`A voice synthesizing system from Digital Equipment Corporation
`that accepts serial ASCII text and converts it into audible speech. It is used in
`Touch—tone telephone response systems as well as for voice—output for visually
`handicapped users.
`
`dedlCated channel A computer channel or communications line that
`is used for one purpose.
`
`dedicated SeI'VlCe A service that is not shared by other users or
`_
`_
`organizations.
`
`defaU|t A standard setting or action taken by hardware or software if the
`user has not specified otherwise. For example, defaults in word processing
`programs define the margins, tabs and page length, all of which can be changed
`by the user.
`
`defragment To reorganize the disk by putting files back into a contiguous
`order.
`
`degausser A device that removes unwanted magnetism from a monitor
`or the read/write head in a disk or tape drive.
`
`DEL key (DELete key) A keyboard
`ltey used to delete the character under the
`screen cursor or some other block of data.
`It is often used in combination with the
`shift, control and alt keys to delete various
`text Segments‘
`
`
`
`delay line A communications or
`electronic circuit that has a builtrin delay. Acoustic delay lines were used to
`create the earliest computer memories. For example, the UNIVAC I used tubes
`of liquid mercury that would slow down the digital pulses long enough (a Fraction
`of a second) to serve as storage.
`
`delete To remove an item of data from a file or to remove a file from the
`disk. See undelete.
`
`he alternatives in a
`
`f
`—l
`h
`I e rec S O tape
`
`.
`
`ment that defines
`rte an executable
`
`Equipment
`[need in 1981’
`
`related products from
`iernetnstyle local area
`broadband, private
`Jnnection of PDP and
`318 as well as PCs and
`ng system.
`tocessing machine and not
`
`at converts a coded
`
`31' f0YI1'1S While
`
`9 original size.
`
`.ber. Decrementing a
`l
`.
`current va ue
`
`gital Equi mam
`DECStati§n 3100 and
`
`m 200 and 300)’
`
`78, that was used
`
`The ComputerGlossary
`
`TheComputerGlossary
`
`i
`
`175
`
`0003
`0003