A Compact Disc is a digital storage medium using an optical disc. While originally developed for audio recording and playback, later in life it found use as storage for all kinds of digital data. Sony was the first brand to openly demonstrate their optical audio disc technology in the late 1970's. In the eighties, compact discs became commercially available, which began the war with audio tape and vinyl. The Compact Disc ultimately emerged the winner of audio formats, only to be replaced themselves by solid state memory storage devices.
Standards and Formats
Standard sized Compact Discs are 1.2 mm thick with a diameter of 120mm. The original storage capacity of a CD was 680 MB or 74 minutes of audio. Currently 700 MB of data or about 80 minutes of audio is what one would typically encounter. However, larger sizes do exist. Also available are smaller Mini CD's which can vary in both size and playback time, but the most common ones are 80 mm in diameter or approximately 3 inches. These hold 24 minutes of audio or 210 MB of data.
In 1979, Sony and Philips collaborated on new ways to make the CD a more efficient storage and playback device, further refining technology started almost five years previous in Sony's case. In a sense, it was this team that "invented" the CD as we know it today as one of the world's most reliable forms of audio playback. One of the first developments to come from the coalition was the Red Book, which defined standard specification for the CD format. Among other details, it sets out the specific guidelines for playback length, deviations, error rate, modulation, and so on.
Becoming commercially available in 1982, the first album to be mass produced on compact disc was Billy Joel's 52nd Street, which was released at the same time as Sony's CD player CDP-101 in October.
For audiophiles of the time, the new Compact Disc seemed to be a dream come true. It was highly praised as the superior method of playback by classical music connoisseurs who were one of the first groups to really get behind the new trend. As the 1980's progressed, the price of CD players slowly fell allowing the format to gain mainstream popularity, especially in the rock and pop categories. By 1989, almost a half billion CDs were manufactured on a yearly basis.
Data and Video on the CD
While it was originally intended as an audio format, the Compact Disc found use as a data storage method for computer programs. In June of 1985, the first CD-ROM was created for use in computers. A few years of progress later saw the development of CD-Recordable (originally called CD-WO) and eventually CD-RW, allowing consumers to record whatever they wanted onto the discs.
In 1987 the CD-V (Compact Disc - Video) was introduced using laser disc technology on a CD format to create moving pictures. The fatal flaw, however, was that there was simply not enough room for the necessary video data, and the format quickly fell into decline, disappearing completely by 1991.
Don't confuse the CD-V with the VCD though. A VCD, or Video Compact Disc, is a more successful video format on CD that was created in 1993. Like audio CDs, a VCD holds either 74 minutes or 80 minutes of video and its quality is roughly the same as a VHS tape. Most DVD players are capable of playing VCDs but VCD players were also manufactured and quite popular in certain parts of the world - especially China and some other Asian countries.
Time continues to march on, however, and the Compact Disc is slowly getting left in the dust. Since the advent of solid state MP3 players, large label CD sales have consistently dropped. The CD still has a place in the computer world, however as an inexpensive way to store data. Though the road has been long, the story of the Compact Disc isn't over yet.