Double Density Compact Disc
Encyclopedia
Double-density compact disc (DDCD) is an optical disc technology developed by Sony
using the same laser wave-length as compact disc
, namely 780 nm. The format is defined by the purple book
standard document.
For a 120 mm 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
s, and shortening the minimum pit length from 0.833 to 0.623 micrometer. The DDCD was also available in read-only format (DDCD-ROM). All three formats existed also in small 80 mm discs.
The technology failed to acquire significant market share before the success of DVD
technology. The DVD technology offered a significantly higher capacity (four times more initially with 4.7 GB on single layer discs, 8.5 GB on dual layer discs to a max of 17.08GB on a dual-side+dual layer disc).
The only DDCD recorder introduced was the Sony CRX200E.
The technology was marked as 'legacy' in the 2006-edition of the SCSI MultiMedia Commands
command set.
Sony
, commonly referred to as Sony, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan and the world's fifth largest media conglomerate measured by revenues....
using the same laser wave-length as compact disc
Compact Disc
The Compact Disc is an optical disc used to store digital data. It was originally developed to store and playback sound recordings exclusively, but later expanded to encompass data storage , write-once audio and data storage , rewritable media , Video Compact Discs , Super Video Compact Discs ,...
, namely 780 nm. The format is defined by the purple book
Rainbow Books
The Rainbow Books are a collection of standards defining the formats of Compact Discs.Red BookYellow BookThe Rainbow Books are a collection of standards defining the formats of Compact Discs.Red Book...
standard document.
For a 120 mm 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
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
s, and shortening the minimum pit length from 0.833 to 0.623 micrometer. The DDCD was also available in read-only format (DDCD-ROM). All three formats existed also in small 80 mm discs.
The technology failed to acquire significant market share before the success of DVD
DVD
A DVD is an optical disc storage media format, invented and developed by Philips, Sony, Toshiba, and Panasonic in 1995. DVDs offer higher storage capacity than Compact Discs while having the same dimensions....
technology. The DVD technology offered a significantly higher capacity (four times more initially with 4.7 GB on single layer discs, 8.5 GB on dual layer discs to a max of 17.08GB on a dual-side+dual layer disc).
The only DDCD recorder introduced was the Sony CRX200E.
The technology was marked as 'legacy' in the 2006-edition of the SCSI MultiMedia Commands
MultiMedia Commands
MultiMedia Commands defines a SCSI/ATA based command set for accessing multimedia features on devices capable of such functionality. T10 subcommittee is responsible for developing it as well as other SCSI command set standards.-See also:...
command set.
See also
- Rainbow BooksRainbow BooksThe Rainbow Books are a collection of standards defining the formats of Compact Discs.Red BookYellow BookThe Rainbow Books are a collection of standards defining the formats of Compact Discs.Red Book...
- CD-RCD-RA CD-R is a variation of the Compact Disc invented by Philips and Sony. CD-R is a Write Once Read Many optical medium, though the whole disk does not have to be entirely written in the same session....
- CD-RWCD-RWA CD-RW is a rewritable optical disc. It was introduced in 1997, and was known as "CD-Writable" during development. It was preceded by the CD-MO, which was never commercially released....
- GD-ROMGD-ROMGD-ROM is the proprietary optical disc format used by the Dreamcast games console, as well as its arcade counterparts and the Sega/Nintendo/Namco Triforce arcade system...
- DVD-ROM
- DVD-RWDVD-RWA DVD-RW disc is a rewritable optical disc with equal storage capacity to a DVD-R, typically 4.7 GB. The format was developed by Pioneer in November 1999 and has been approved by the DVD Forum. The smaller Mini DVD-RW holds 1.46 GB, with a diameter of 8 cm.The primary advantage of DVD-RW over...
- HD DVDHD DVDHD DVD is a discontinued high-density optical disc format for storing data and high-definition video.Supported principally by Toshiba, HD DVD was envisioned to be the successor to the standard DVD format...
- Blu-Ray
- MultiLevel RecordingMultiLevel RecordingMultiLevel Recording was a technology originally developed by Optex Corporation and promoted by Calimetrics to increase the storage capacity of optical discs. It failed to establish itself on the market...
External links
- WORLD PC EXPO 2000 with photos of That's Double Density CD-R by Taiyo YudenTaiyo Yudenis a Japanese materials and electronics company, situated in Ueno, Taito, Tokyo, that helped pioneer recordable CD technology along with Sony and Philips in 1988. Founded 60 years ago, Taiyo Yuden currently operates factories in Japan, Singapore, Korea, China, the Philippines, Taiwan, Malaysia,...