CD and DVD Covers

A Different Kind of Upgrade

The Compact Disc is a spin-off of Laserdisc engineering science. Sony first publicly presented an optical digital audio disc in September 1976. In September 1978, they demonstrated an optical digital sound recording disc with provisions of 16-bit linear result, 44,056 Hz sample delivery rate, cross-interleaved error alteration system also with a 150 minute playing time, that were akin to those of the Compact Disc introduced in 1982. On March 13 to 16, 1979, technological details the digital sound recording disc of Sony were presented during the 62nd AES Convention in Brussels. Philips publicly demonstrated on March 8, 1979, at a news conference in Eindhoven, Netherlands, called ‘Philips Introduce Compact Disc’ a prototype of an optical digital sound recording disc.

Some Noted Historical Events

Later in 1979, Sony and Philips Consumer Electronics (Philips) set up a joint task force of masterminds to design a new digital sound recording disc. During 1975 and 1977, Sony and Philips had separate attempts in optical disc and laser technology and Toshitada Doi and Kees Schouhamer Immink led the research program. After a year of experiment and discussion, the taskforce produced the Red Book, the Compact Disc criterion. Philips added the general manufacturing process, based on video Laserdisc technology. The said company also added a feature which offers both a high resilience against disc defects such as finger marks which is referred to as the EMF or the eight-to-fourteen modulation and plus the addition of a long playing time output, while Sony added the error-correction system, CIRC. According to a recent member of the taskforce, the Compact Disc Story gives background knowledge information on some Technical conclusions made, including the option of the sample distributions frequency, playing time, and disc measurements. The team composed of around four to eight experts; however Philips asserted that the Compact Disc was thus formulated cooperatively by a big group of individuals running as a squad.

Some Measurements

Usually a normal compact disk of 120 millimeter could contain eighty minutes of uncompressed audio or 700 MB of information or data. Other compact disk variations such as the sixty and eighty millimeter sizes could store, more or less, twenty-four minutes of sound files. As per upgrades are concern, the once ‘read-only memory’ or ROM compact discs evolved into writable and re-writable media. Since this the emergence of this great invention, compact disc stays one of the necessities of digital domain. Its sales in the world market had almost reached thirty billion discs in 2004 and by the end of 2007; 200 billion discs had already been sold.

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