Compact Disc Recordable
<storage> (CD-R) A write-once version of CD-ROM. CD-Rs can hold about 650 megabytes of data. They are very durable and can be read by normal CD-ROM drives, but once data has been written it cannot be altered.
Standard prerecorded CDs have their information permanently stamped into an aluminium reflecting layer. CD-R discs have a dye-based recording layer and an additional golden reflecting layer.
Digital information is written to the disc by burning (forming) pits in the recording layer in a pattern corresponding to that of a conventional CD.
The laser beam heats the substrate and recording layer to approximately 250 C. The recording layer melts and the substrate expands into the space that becomes available.
(01 Apr 1999)
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