The Yellow Book itself is not freely available, but the standards with the corresponding content can be downloaded for free from ISO or ECMA. Other standards, such as the White Book for Video CDs, further define formats based on the CD-ROM specifications. The CD-ROM standard builds on top of the original Red Book CD-DA standard for CD audio. The Yellow Book, created in 1983, defines the specifications for CD-ROMs, standardized in 1988 as the ISO/ IEC 10149 standard and in 1989 as the ECMA-130 standard. Several formats are used for data stored on compact discs, known as the Rainbow Books. Because the depth of the pits is approximately one-quarter to one-sixth of the wavelength of the laser light used to read the disc, the reflected beam's phase is shifted in relation to the incoming beam, causing destructive interference and reducing the reflected beam's intensity. A laser is shone onto the reflective surface of the disc to read the pattern of pits and lands. The most common size of CD-ROM is 120 mm in diameter, though the smaller Mini CD standard with an 80 mm diameter, as well as shaped compact discs in numerous non-standard sizes and molds (e.g., business card-sized media), also exist.ĭata is stored on the disc as a series of microscopic indentations called "pits", with the non-indented spaces between them called "lands". Discs are made from a 1.2 mm thick disc of polycarbonate plastic, with a thin layer of aluminium to make a reflective surface. Some computers which were marketed in the 1990s were called " multimedia" computers because they incorporated a CD-ROM drive, which allowed for the delivery of several hundred megabytes of video, picture, and audio data.Ī CD-ROM in the tray of a partially open CD-ROM drive.ĬD-ROMs are identical in appearance to audio CDs, and data are stored and retrieved in a very similar manner (only differing from audio CDs in the standards used to store the data). By early 1990, about 300,000 CD-ROM drives were sold in Japan, while 125,000 CD-ROM discs were being produced monthly in the United States. In 1990, Data East demonstrated an arcade system board that supported CD-ROMs, similar to 1980s laserdisc video games but with digital data, allowing more flexibility than older laserdisc games. ĬD-ROMs began being used in home video game consoles starting with the PC Engine CD-ROM² (TurboGrafx-CD) in 1988, while CD-ROM drives had also become available for home computers by the end of the 1980s. One of the first CD-ROM products to be made available to the public was the Grolier Academic Encyclopedia, presented at the Microsoft CD-ROM Conference in March 1986. It was eventually standardized, with a few changes, as the ISO 9660 standard in 1988. The resulting specification, called the High Sierra format, was published in May 1986. In November, 1985, several computer industry participants including Microsoft, Philips, Sony, Apple and Digital Equipment Corporation met to create a specification to define a file system format for CD-ROMs. The CD-ROM was announced in 1984 and introduced by Denon and Sony at the first Japanese COMDEX computer show in 1985. Sony and Philips created the technical standard that defines the format of a CD-ROM in 1983, in what came to be called the Yellow Book. The CD-ROM was later designed an extension of the CD-DA, and adapted this format to hold any form of digital data, with an initial storage capacity of 553 MB. The result was the Compact Disc Digital Audio (CD-DA), defined on 1980. Key work to digitize the optical disc was performed by Toshi Doi and Kees Schouhamer Immink during 1979–1980, who worked on a taskforce for Sony and Phillips. The LaserDisc was the immediate precursor to the CD, with the primary difference being that the LaserDisc encoded information through an analog process whereas the CD used digital encoding. In particular, Gregg's patents were used as the basis of the LaserDisc specification that was co-developed between MCA and Philips after MCA purchased Gregg's patents, as well as the company he founded, Gauss Electrophysics. The earliest theoretical work on optical disc storage was done by independent researchers in the United States including David Paul Gregg (1958) and James Russel (1965–1975).
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