The time has come for Toshiba and Nec, the main backers of HD-DVD format to announce they're ready for write-once HD-DVD-R disc mass production.

Their discs can store 15 GB of data, and should be available for the consumers in the first half of the next year, by the same time that HD-DVD recorders and PC drives will be also on the market.

As we all know, HD-DVD fights in a tight competition with Blu-ray for the format of the future title, that also means a multibillion dollar market as a price for the winner.

Similar blue laser technology stays at the core of both formats, as the blue laser has a shorter wavelength than the red lasers used in current DVD equipment, allowing discs to store data at higher densities needed for high-definition TV and movies.

The advantage that HD-DVD-R disc has over its main competitor, the Blu-ray disc is it has the same disc structure as the classic DVD and thus can be manufactured by using the same production lines. This, for the DVD manufacturers, means they can start HD-DVD-R mass production at full speed, right away, with not much additional cost. A replacement stamper is needed of course and the old dye must be replaced with blue-light sensitive, resin dye. The new dye was developed in a joint project of Hayashibara Biochemical Laboratories, Mitsubishi Kagaku Media/Verbatim and Toshiba Corporation.

But at the same time, Blu-ray competitor has its own advantages, like superior storing capacity. Toshiba claims it works at this aspect also, but moving from single-layer discs that are written at 1x speed, to dual-layer 30GB discs could take several years, its spokespersons said. Toshiba promised to introduce 20GB HD-DVD-RW discs by this time next year.

So far, the Blu-ray Disc Association and the HD DVD Promotion Group have refused to compromise to a unified hybrid format for the future DVD.