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CD-R (Compact Disc-Recordable) is a digital optical disc storage format. A CD-R disc is a compact disc that can be written once and read arbitrarily many times. CD-R disks (CD-Rs) are readable by most plain CD readers, i.e., CD readers manufactured prior to the introduction of CD-R. This is an advantage over CD-RW, which can be re-written but cannot be played on many plain CD readers. ==History== The CD-R,originally named CD Write-Once (WO), specification was first published in 1988 by Philips and Sony in the 'Orange Book'. The Orange Book consists of several parts, furnishing details of the CD-WO, CD-MO (Magneto-Optic), and CD-RW (ReWritable). The latest editions have abandoned the use of the term "CD-WO" in favor of "CD-R", while "CD-MO" were used very little. Written CD-Rs and CD-RWs are, in the aspect of low-level encoding and data format, fully compatible with the audio CD (''Red Book'' CD-DA) and data CD (''Yellow Book'' CD-ROM) standards. (Note that the Yellow Book standard for CD-ROM only specifies a high-level data format and refers to the Red Book for all physical format and low-level code details, such as track pitch, linear bit density, and bitstream encoding.) This means they use Eight-to-Fourteen Modulation, CIRC error correction, and, for CD-ROM, the third error correction layer defined in the Yellow Book. Properly written CD-R discs on blanks of less than 80 minutes length are fully compatible with the audio CD and CD-ROM standards in all details including physical specifications. 80 minute CD-R discs marginally violate the Red Book physical format specifications, and longer discs are noncompliant. CD-RW discs have lower reflectivity than CD-R or pressed (non-writable) CDs and for this reason cannot meet the Red Book standard (or come close). Some hardware compatible with Red Book CDs may have difficulty reading CD-Rs and, because of their lower reflectivity, especially CD-RWs. To the extent that CD hardware can read extended-length discs or CD-RW discs, it is because that hardware has capability beyond the minimum required by the Red Book and Yellow Book standards (the hardware is more capable than it needs to be to bear the Compact Disc logo). CD-R recording systems available in 1990 were similar to the washing machine-sized Meridian CD Publisher, based on the two-piece rack mount Yamaha PDS audio recorder costing $35,000, not including the required external ECC circuitry for data encoding, SCSI hard drive subsystem, and MS-DOS control computer. By 1992, the cost of typical recorders was down to $10–12,000, and in September 1995, Hewlett-Packard introduced its model 4020i manufactured by Philips, which, at $995, was the first recorder to cost less than $1000.〔(Roxio history of CD-R ) from Roxio Newsletter 17 January 2000. Retrieved 19 September 2009〕 The dye materials developed by Taiyo Yuden made it possible for CD-R discs to be compatible with Audio CD and CD-ROM discs. Initially, in the United States, there was a market separation between "music" CD-Rs and "data" CD-Rs, the former being several times more expensive than the latter due to industry copyright arrangements with the RIAA.〔(A New Spin ), ''TIME Magazine'', August 24, 1998〕 Physically, there is no difference between the discs save for the Disc Application Flag that identifies their type: standalone audio recorders will only accept "music" CD-Rs to enforce the RIAA arrangement, while computer CD-R drives can use either type of media to burn either type of content. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「CD-R」の詳細全文を読む スポンサード リンク
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