CD-ROM

A CD-ROM , compact disc read-only memory is the pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs, i.e. this is the a type of read-only memory. Some CDs, called enhanced CDs, defecate both computer data in addition to audio with the latter capable of being played on a CD player, while data such(a) as software or digital video is only available on a data processor such as ISO 9660 an arrangement of parts or elements in a specific form figure or combination. PC CD-ROMs.

During the 1990s, CD-ROMs were popularly used to distribute software together with data for computers and fifth brand video game consoles.

History

The earliest theoretical earn believe on optical disc storage was done by freelancer researchers in the United States including David Paul Gregg 1958 and James Russel 1965–1975. 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 living as the organization he founded, Gauss Electrophysics. The LaserDisc was the instant precursor to the CD, with the primary difference being that the LaserDisc encoded information through an analog process whereas the CD used digital encoding.

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 result was the Compact Disc Digital Audio CD-DA, defined on 1980. The CD-ROM was later intentional an character of the CD-DA, and adapted this configuration to hold all form of digital data, with an initial storage capacity of 553 MB. 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 announced in 1984 and gave by Denon and Sony at the first Japanese COMDEX computer show in 1985. In November, 1985, several computer industry participants including Microsoft, Philips, Sony, Apple and Digital Equipment Corporation met to create a specifications to define a file system format for CD-ROMs. The resulting specification, called the High Sierra format, was published in May 1986. It was eventually standardized, with a few changes, as the ISO 9660 standard in 1988. One of the first CD-ROM products to be made usable to the public was the Grolier Academic Encyclopedia, provided at the Microsoft CD-ROM Conference in March 1986.

CD-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. 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. 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. Some computers which were marketed in the 1990s were called "multimedia" computers because they incorporated a CD-ROM drive, which offers for the delivery of several hundred megabytes of video, picture, and audio data.