Toshiba DVD camp unveils rewritable format

Electronic News, May 29, 1995 by Rob Guth

TOKYO--Toshiba Corp. and its partners fired another salvo in the battle over next-generation digital videodisk (DVD) formats last week when they announced a rewritable phase-change 5.2GB disk format.

The Toshiba camp's SD-RAM (super density RAM) rewritable format uses phase-change optical technology to hold 2.6GB of data on each side of a double-sided disk. It has been endorsed by three disk makers: Asahi Chemical Industry Co. Ltd. and Toray Industries Inc., both based in Japan, and Plasmon Plc, of the UK.

The SD alliance, which has previously announced ROM and write-once technology, now expects Sony to counter with a similar announcement, said a Toshiba spokesperson.

At Sony, which has teamed with Philips to push its own DVD format, introduction of a rewritable DVD product is possible, a company spokesperson said. "We are doing R&D on a rewritable disk, but the format itself is still under consideration," he said, "The computer makers want a single-sided format because it's easier to access."

Five major computer hardware and software companies--Apple Computer, Compaq Computer, Hewlett-Packard, IBM and Microsoft-- recently sought a compromise to the industry's DVD standards battle (EN, May 15). The five computer companies said their primary objectives are a single interchange standard for both TV-based and PC-based applications; backward read-compatibility with existing compact discs; forward compatibility with future read/write and write-once discs; a single file system for both entertainment and computer-based content; and low cost.

Philips/Sony have been positioning their technology as the most computer-friendly. They recently added Mitsumi Electric, TEAC and Ricoh as supporters of their DVD format, which has specifications for a DVD capable of storing 7.4GB on one side with a dual layer technique.

However, the Toshiba camp has been bolstered by the contributions of Matsushita, whose technology is believed to be employed in the new rewritable phase-change 5.2GB disk format. In addition, Matsushita has developed a dual-layer disc that can play back up to 9GB of data from a single side. The original specification from Toshiba had called for a double-side 10GB disk.

It will be late next year before any of the Toshiba alliance members, including Hitachi Ltd. and Pioneer Electric Corp., market products based on the DVD format. Time Warner also supports the SD specification, which has garnered wide backing in the entertainment industry; other supporters include Thomson Consumer Electronics S.A., Zenith Electronics and Samsung.

Toshiba claims its format is compliant with the requirements put forth by computer makers. "Support from both the content and consumer electronics industries, and compliance with computer industry feature requirements, make the SD format suitable as a single standard for home video as well as multimedia PC applications," the company said.