The double-density compact disc (DDCD) is an optical disc technology developed by

Sony , commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...

using the same laser wavelength as a

compact disc The compact disc (CD) is a digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then released in Oc ...

, namely 780 nm. The format is defined by the ''Purple Book'' standard document. Unlike the compact-disc technology it is based on, DDCD was designed exclusively for data with no audio capabilities. For a 12 cm disc, it doubles the original 650 MB to 1.3 GB capacity of a CD on recordable (DDCD-R) and rewritable (DDCD-RW) discs by narrowing the track pitch from 1.6 to 1.1

micrometer Micrometer can mean: * Micrometer (device), used for accurate measurements by means of a calibrated screw * American spelling of micrometre The micrometre ( international spelling as used by the International Bureau of Weights and Measures; ...

s, and shortening the minimum pit length from 0.833 to 0.623 micrometers. The DDCD was also available in read-only format (DDCD-ROM). The specification allowed for both 12 cm and 8 cm discs, although it appears no 8 cm media was ever released. The technology, released years after rewritable DVD technology, failed to acquire significant market share. The only DDCD recorder introduced was the Sony CRX200E. While the initial launch price of the drive and the disc ($249 and $2-3 respectively) was lower than the prices of DVD-RW drives and media ($1000 and $10 respectively), an 85% increase in storage compared to the standard 700 MB CDs was not enough to entice customers. A similar technology, however, was used in the GD-ROM discs primarily used for

Sega Dreamcast The is a home video game console released by Sega on November 27, 1998, in Japan; September 9, 1999, in North America; and October 14, 1999, in Europe. It was the first sixth-generation video game console, preceding Sony's PlayStation 2, Nint ...

software. DVD offered a significantly higher capacity - nearly four times more than DDCD-R with 4.7 GB on single layer discs and six and a half times more with 8.5 GB on double layer discs and would drop significantly in cost in the years after DDCD's launch. The DDCD technology was marked as 'legacy' in the 2006-edition of the

SCSI Multimedia Commands SCSI Multimedia Commands (MMC) defines a SCSI/ ATAPI based command set for accessing and controlling devices of type 05h. Such devices read or write optical media: CD, DVD, BD. T10 subcommittee is responsible for developing MMC as well as oth ...

set (MMC).

Competition

DDCD was part of a wave of technologies aimed at enhancing the compact disc, none of which managed to gain much market share.

MultiLevel Recording MultiLevel Recording (ML, also known as M-ary) was a technology originally developed by Optex CorporationEarman, Allen, "Optical Data Storage With Electron Trapping Materials Using M-ary Data Channel Coding," Proceedings of the Optical Data Storag ...

, developed in 1992 by Optex Corporation, was a proposed technology that never saw the light of the day. It promised to burn 2 GB onto one CD and a couple of disc burners from

TDK is a Japanese multinational electronics corporation that manufactures electronic components and recording and data-storage media. Its motto is "Contribute to culture and industry through creativity". "TDK" is an initialism of the original Ja ...

and

Plextor Plextor (styled PLEXTOR) ( zh, 浦科特; ja, プレクスター) is a Taiwanese (formerly Japanese) consumer electronics brand, best known for solid-state drives and optical disc drives. Company The brand name Plextor was used for all products ...

were set for release in 2002 for $200 with discs costing around $2. No ML products were ever released. In September 2002,

Sanyo , stylized as SANYO, is a Japanese electronics company and formerly a member of the ''Fortune'' Global 500 whose headquarters was located in Moriguchi, Osaka prefecture, Japan. Sanyo had over 230 subsidiaries and affiliates, and was founded by ...

announced it had achieved the same result as DDCD using standard CD-Rs with its HD-Burn technology. This allowed users to burn 1.4 GB on a standard 700 MB CD. However, the resulting CD could only be played back on DVD drives. In 2003,

released a CD burner that utilized their proprietary GigaRec technology to allow users to burn a maximum of 980 MB on a standard 80 minute CD and 1.2 GB of a 99 minute CD. Like DDCD, the result was achieved by burning smaller pits. The resulting disc could be read perfectly on Plextor GigaRec drives. Results with reading the disc on other optical drives were mixed.

References

External links

* *
WORLD PC EXPO 2000
with photos of That's Double Density CD-R by

Taiyo Yuden is a Japanese materials and electronics company, situated in Kyobashi, Chuo, Tokyo, that helped pioneer recordable CD technology (CD-R) along with Sony and Philips in 1988. Founded 70 years ago, Taiyo Yuden currently operates factories in Japa ...

120 mm discs Audio storage Video storage Optical computer storage media {{tech-stub

Competition

See also

References

External links