| In January 1995, Time Warner and
Toshiba were working on a new super density CD-like format called SD-ROM while Sony and
Philips had joined forces to back the Multimedia Compact Disk (MMCD) format. Then, in
September of 1995, the competing companies compromised to form one consortium for the new
high-density optical disk - DVD, the Digital Video Disc, was born. The new DVD discs have the same physical characteristics of the standard CD, with a storage capacity seven times the data of CD: 4.7 gigabytes per single side, as compared to 680 megabytes for CD. Also DVD offers a dual-layer, single-side option, for an even higher capacity: 8.5 gigabytes on a single side or 17.0 gigabytes on a double-sided disc. Almost every aspect of DVD was developed, refined, or reinvented to achieve the seven-fold increase in data capacity and data density. Refinements include smaller pit dimensions, a more closely-spaced track (finer "track pitch"), and ashorter-wavelength laser. |