WordNet (r) 3.0 (2006):

compact disc read-only memory
    n 1: 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 user [syn: CD-ROM, compact disc read-only
         memory]

The Free On-line Dictionary of Computing (30 December 2018):

Compact Disc Read-Only Memory
CD-ROM
CD-ROM drive

    (CD-ROM) A non-volatile optical data storage
   medium 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.  The
   maximum capacity is about 600 megabytes.  A CD can store
   around 640 megabytes of data - about 12 billion bytes per
   pound weight.

   CD-ROM drives are rated with a speed factor relative to music
   CDs (1x or 1-speed which gives a data transfer rate of 150
   kilobytes per second).  12x drives were common in April
   1997.  Above 12x speed, there are problems with vibration and
   heat.  Constant angular velocity (CAV) drives give speeds up
   to 20x but due to the nature of CAV the actual throughput
   increase over 12x is less than 20/12.

   20x was thought to be the maximum speed due to mechanical
   constraints but on 1998-02-24, Samsung Electronics
   introduced the SCR-3230, a 32x CD-ROM drive which uses a ball
   bearing system to balance the spinning CD-ROM in the drive to
   reduce noise.

   CD-ROM drives may connect to an IDE interface, a SCSI
   interface or a propritary interface, of which there are three
   - Sony, Panasonic, and Mitsumi.  Most CD-ROM drives can also
   play audio CDs.

   There are several formats used for CD-ROM data, including
   Green Book CD-ROM, White Book CD-ROM and Yellow Book
   CD-ROM.  ISO 9660 defines a standard file system, later
   extended by Joliet.

   See also Compact Disc Recordable, Digital Versatile Disc.

   Byte, February 1997
   (http://byte.com/art/9702/sec17/art5.htm).

   (2006-09-25)