Double Density Compact Disc
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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 120 mm disc radius, 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 micrometers, 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 disc radius.
The technology failed to conquer 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, and eventually 8.5 GB on dual layer discs)
The only DDCD recorder introduced was the Sony CRX200E.
The technology was marked as 'legacy' in the 2006 edition of the MMC command set (Multi-Media Commands).
[edit] See also
[edit] External links
- WORLD PC EXPO 2000 with photos of That's Double Density CD-R by Taiyo Yuden
