red book

Wednesday, October 18, 2006

CD-ROM

When Sony and Philips invented the Compact Disc (CD) in the early 1980s, even they couldn't ever have imagined what a versatile carrier of information it would become. Launched in 1982, the audio CD's durability, random access features and audio quality made it incredibly successful, capturing the majority of the market within a few years. CD-ROM followed in 1984, but it took a few years longer to gain the widespread acceptance enjoyed by the audio CD. This consumer reluctance was mainly due to a lack of compelling content during the first few years that the technology was available. However, there are now countless games, software applications, encyclopaedias, presentations and other multimedia programs available on CD-ROM and what was originally designed to carry 74 minutes of high-quality digital audio can now hold up to 650MB of computer data, 100 publishable photographic scans, or even 74 minutes of VHS-quality full-motion video and audio. Many discs offer a combination of all three, along with other information besides.
Today's mass produced CD-ROM drives are faster and cheaper than they've ever been. Consequently, not only is a vast range of software now routinely delivered on CD-ROM, but many programs (databases, multimedia titles, games and movies, for example) are also run directly from CD-ROM - often over a network. The CD-ROM market now embraces internal, external and portable drives, caddy- and tray-loading mechanisms, single-disc and multichanger units, SCSI and EIDE interfaces, and a plethora of standards.
In order to understand what discs do what and which machine will read what, it is necessary to identify clearly the different formats. The information describing a CD standard is written on pages bound between the coloured covers of a book. A given standard is known by the colour of its cover. All CD-ROM drives are Yellow Book- and Red Book-compatible, along with boasting built-in digital-to-analogue converters (DACs) which enable you to listen to Red Book audio discs directly through headphone or line audio sockets.