CompuServe Thread

>>Someone can tell me if there is a physical difference between a recordable CD Audio and a CD Rom? There is a physical difference between a recordable CD and any type of pressed CD. There is no physical difference between types of pressed CDs. Pressed CDs are made of polycarbonate, aluminum, and lacquer. Recordable CDs are made of polycarbonate, dye polymer, gold, and UV-cured lacquer. Pressed CDs have data molded into them in the form of pits and lands. Recordable CDs have a "pregroove" molded into them, which guides the laser of a desktop recorder. The laser heats the dye polymer, which reacts with the polycarbonate, and forms pits, which represent data.

I'm not quite sure if you're asking this, but in case you are: There are some new types of recordable discs out, notably from TDK, which are intended for use only in some new CD recorders which can only be used to copy audio CDs. (I believe there's some copy protection scheme built in there,but don't quite know how it works yet). Anyway, the discs have a protection bit that is recognized by CD recorders so that they can _only_ be written in the special machines they were intended for. This is also true of the Kodak discs made for Photo CD service shops — they cost less than the recordable discs we all buy, but can't be used in any system except the Kodak Photo CD workstations. Best, Deirdre' Straughan Incat Systems