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.

Phillips: New Technologies.

See also CD-RW and DVD-RAM.

(1999-08-01)