释义 |
compact disc read-only memory ThesaurusNoun | 1. | compact disc read-only memory - a compact disk that is used with a computer (rather than with an audio system); a large amount of digital information can be stored and accessed but it cannot be altered by the userCD-ROMcompact disc, compact disk, CD - a digitally encoded recording on an optical disk that is smaller than a phonograph record; played back by a laserfixed storage, read-only memory, read-only storage, ROM - (computer science) memory whose contents can be accessed and read but cannot be changed |
Compact Disc Read-Only Memory
Compact Disc Read-Only Memory (storage)(CD-ROM) A non-volatile optical data storagemedium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive.
CD-ROM is popular for distribution of large databases,software and especially multimedia applications. Themaximum capacity is about 600 megabytes. A CD can storearound 640 megabytes of data - about 12 billion bytes perpound weight.
CD-ROM drives are rated with a speed factor relative to musicCDs (1x or 1-speed which gives a data transfer rate of 150kilobytes per second). 12x drives were common in April1997. Above 12x speed, there are problems with vibration andheat. Constant angular velocity (CAV) drives give speeds upto 20x but due to the nature of CAV the actual throughputincrease over 12x is less than 20/12.
20x was thought to be the maximum speed due to mechanicalconstraints but on 1998-02-24, Samsung Electronicsintroduced the SCR-3230, a 32x CD-ROM drive which uses a ballbearing system to balance the spinning CD-ROM in the drive toreduce noise.
CD-ROM drives may connect to an IDE interface, a SCSIinterface or a propritary interface, of which there are three- Sony, Panasonic, and Mitsumi. Most CD-ROM drives can alsoplay audio CDs.
There are several formats used for CD-ROM data, includingGreen Book CD-ROM, White Book CD-ROM and Yellow Book CD-ROM. ISO 9660 defines a standard file system, laterextended by Joliet.
See also Compact Disc Recordable, Digital Versatile Disc.
Byte, February 1997.MedicalSeeCD-ROMcompact disc read-only memory
Synonyms for compact disc read-only memorynoun a compact disk that is used with a computer (rather than with an audio system)SynonymsRelated Words- compact disc
- compact disk
- CD
- fixed storage
- read-only memory
- read-only storage
- ROM
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