CD-ROM

(redirected from CD-ROMs)
Also found in: Dictionary, Thesaurus, Medical.

CD-ROM:

see compact disccompact disc
(CD), a small plastic disc used for the storage of digital data. As originally developed for audio systems, the sound signal is sampled at a rate of 44,100 times a second, then each sample is measured and digitally encoded on the 4 3-4 in (12 cm) disc as a series of
..... Click the link for more information.
.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/

CD-ROM

[¦sē¦dē ′räm]
(computer science)
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

CD-ROM

compact disc read-only memory; a compact disc used with a computer system as a read-only optical disk
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005

CD-ROM

This article is provided by FOLDOC - Free Online Dictionary of Computing (foldoc.org)

CD-ROM

(Compact Disc-Read Only Memory) A type of CD disc that can only be read, but not recorded. Used to store programs and data files, a CD-ROM holds 650MB or 700MB of data and employs a different recording format than the audio CD (CD-DA), from which it evolved. In the 1990s, the CD-ROM rapidly replaced the floppy disk for software distribution.

An audio CD player cannot read CD-ROMs, but CD-ROM drives can play audio discs. In practice, the term "CD" refers to all CD formats. The phrase "insert the installation CD" really means "insert the installation CD-ROM."

How CD-ROMs Are Made
CD-ROMs are made by "burning" a blank CD-R disc and sending it to a media manufacturer, which creates a master disc that is used to stamp out the required quantity. See CD-R and mini CD.

Pretty Slow in the Beginning
Back in the late 1980s, the first CD-ROM drives transferred data at 150KB per second. By doubling the spindle speed from 530 to 1,060 RPM, the transfer rate doubled to 300KB (2x). For several years thereafter, speeds increased until reaching 48x and higher, making the "1x" drive painfully slow by comparison. For details about speeds, see CD-ROM drives. Access times range from 80 to 150ms. See CD-R, CD-RW, DVD and optical disc.


Caddy Load and Tray Load
Earlier drives used a caddy. The disc must be inserted into the caddy, and the caddy inserted into the drive. Today, drives are caddyless. The disc is placed into a tray.




Caddy Load and Tray Load
Earlier drives used a caddy. The disc must be inserted into the caddy, and the caddy inserted into the drive. Today, drives are caddyless. The disc is placed into a tray.







Reading CDs and CD-ROMs
Digital data are carved into the disc as pits (low spots) and lands (high spots). As the laser shines into the moving pits and lands, a sensor detects a change in reflection when it encounters a transition from pit to land or land to pit. Each transition is a 1. The lack of transitions are 0s. There is only one laser in a drive. Two are used here to illustrate the difference in reflection.







Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
One black-owned firm that comes to mind is Ember Media, a full-service digital media production studio and CD-ROM publishing company based in New York.
Silico-Magnetic Intelligence Corp., Nanuet, N.Y., has released a full-motion video and audio CD-ROM training course for Microsoft SQL Server 2005 Programming.
We will call this small piece of wood the "wood support." Next, drill two 1/8" holes in two CD-ROMs where shown in Drawing 2A.
An evaluation team consisting of two college professors and one third grade elementary teacher was established to select one basal reader text with a companion CD-ROM. The five basal reader texts reviewed were based on age appropriateness, the content, and the level of vocabulary using Fry's readability graph (Tonjes & Zintz, 1992).
Mastering the full-motion screen image video 21 CD-ROMs SQL Server Administration training series is equivalent to three years' on-the-job experience.
Specifically, I see problems in the way librarians are incorporating interim rapid-action changes (IRACs) into NavAir publications, both on paper and on CD-ROM. Some people see this problem as a small issue, but the function is critical to the safe maintenance and operation of naval aircraft.
The Interactive Video CD-Rom is crammed with the sights and sounds of the Harp Lager Belfast Giants' success story throughout 2001 and 2002.
CD-ROM was the first popular optical disc technology used with PCs.
(Programmable CD-ROMs, in case you hadn't guessed, are write-once media, not rewritable.) The content publisher ends up with a disk that--so far, at least--can be considered unduplicatable.
Roberta Astroff explores the evaluation and selection of CD-ROMs containing full-text literary works.
In order to carry out a search of the full version and full version backfile, it is necessary to swap CD-ROMs. Both the expert and compound search modes have the facility of saving and then restoring searches, so you can create and execute a search on the current CD-ROM, save the search strategy, exit the application, swap to the Backfile CD-ROM(s) and then restore the search.