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CD, CD-R, CD-RW and DVD: A Family in Turmoil

Speed of technological change seems inevitable. Sometimes speed gets you where you want to go faster, but sometimes speed kills. Speed in product development and rush to market rather than well considered long-term planning has come on the scene to infect well-ordered CD marketing.

CD, CD-R, CD-RW and DVD: A Family in Turmoil

Hugh Bennett
EMedia Professional, April 1997

The compact disc family evolved slowly from its single read-only infancy, through early write-once adolescence, to a now promised maturity that includes rewritable and high density, in the forms of CD-RW and DVD. The compact disc progress acknowledged that one format does not satisfy every requirement and that diversification better suits real and perceived needs and desires.

CD-Rewritable (CD-RW) is the first erasable format to bear the CD moniker and arrives amid much media expectation and considerable fanfare on the part of its promoters. But the questions remain: What impact will CD-RW really have on the market and its perception of CD and 120mm products in general? Will the release of CD-RW be positive or negative for the future of the CD family?

The idea of a rewritable compact disc is nothing new. Back in 1988 Tandy Corporation claimed to have developed an inexpensive erasable disc, called the Tandy High Intensity Optical Recording-Compact Disc (THOR-CD), fully playback compatible with existing CD-Audio and CD-ROM drives. THOR-CD never came to market, but the dream lived on. Back then, when expectations were still very much undefined, something like THOR-CD may well have revolutionized CDs. And even today something the same would still be warmly received. But the promise of THOR-CD is not the promise of CD-RW.

The problem with CD-RW, quite simply, is its lack of backward compatibility. If CD-Rewritable were backward compatible it would be consistent with the philosophy that has made CD and CD-R so successful and could have a significant impact on the market. However, CD-RW is deficient in this regard. The fact is that existing CD-ROM and CD-R devices cannot read CD-RW discs due to a difference in media reflectivity, and CD-RW discs are incompatible with every one of the 120 million existing CD-ROM drives and over a half billion other compact disc devices. Even compatibility with anticipated new and future “MultiRead” CD drives is only a promise on the part of some hardware manufacturers and not a formal standard from the CD licensors.

A principle reason for the success of compact disc technology to date is the universal guarantee that discs can be read by almost any computer with a CD-ROM drive, anywhere in the world. CD-Recordable shares this compelling nature and, as a result, has proven very successful. But this is not the case with CD-RW. The consequence of CD-RW’s incompatible nature is that CD-RW discs will most likely never leave the hardware that writes them and thus will be relegated to simple on-board chores. Without a means to be a widely readable media for data, CD-RW will not become the runaway market success and replacement for CD-R predicted by many enthusiastic promoters.

No disc is an island. As in life, where we are all connected and dependent upon one another (whether we acknowledge it or not), so the members of the compact disc family must be dependent upon and support each other. Like a wayward child, CD-RW neither admits to its dependency nor understands that its success hinges upon something bigger than itself. While some data storage systems that go it alone have survived or enjoyed limited success — MO comes to mind, and the phase change/CD combo drives pioneered by such companies as Panasonic — they always lack the inherent potential to thrive like CD and CD-R. Without backward and guaranteed forward compatibility, CD-RW is just another one of these iconoclastic voices in the crowd of data storage options.

Cost and extendibility are other serious deviations of CD-RW from a successful compact disc philosophy. Winning formats are traditionally based on well considered projections including long-term manufacturing cost, migration paths, and future applications. Until the arrival of CD-RW, the compact disc family followed these tenets, but that picture is now blurred: unlike CD, CD-RW lacks a clear migration path to DVD, nor does it provide a pathway to add low-cost higher-speed recording capabilities to extend its use, condemned as CD-RW is to double-speed (2X) writing.

Releasing CD-RW into the mature compact disc market is confusing and harmful to sales by giving the impression that manufacturers are not concerned with protecting good-faith technology investments already made by satisfied CD users. Undermining CD’s foundations at this late stage may also invite cynicism and rightfully carry over to DVD, where planning for DVD and its derivatives, DVD-Recordable (DVD-R) and DVD-Rewritable (DVD-RAM), become equally suspect.

The lessons of compact disc history also seem to have been lost on DVD. Given current experiences with the problems of reading CD-R discs at the shorter wavelengths prescribed by DVD drives and players, it would be hoped that manufacturers would design new products so as to avoid even further incompatibilities when DVD is eventually replaced by technology using still shorter wavelength (430nm) blue lasers.

But this is not the case. Incredibly, several media manufacturers are planning DVD-Recordable (DVD-R) discs again incorporating wavelength-dependent materials, dooming users to encounter the same compatibility problems when the next generation of equipment arrives on the scene. Relying on non-panchromatic materials is remarkably short-sighted since it encumbers the future by missing the chance to use an even shorter wavelength recording laser (such as green) to achieve yet higher data capacity. Narrow wavelength tolerances also lead to higher media and hardware costs. These costs could be easily avoided by more careful planning in the development stage.

Another example of the deterioration of the unity and clarity of thinking that originally defined the CD family is the fact that the first-generation — and, likely enough, many second-generation — DVD-ROM drives will not be able to read DVD-RAM discs when DVD-RAM becomes available in 1998.

This is not an unforeseen problem that cropped up out of nowhere. The members of the DVD Consortium, the Technical Working Group (TWG), and their allies long ago saw it coming but were more concerned with rushing products to market rather than conforming to a philosophy that would ensure long-term success by filling real-world needs and protecting technological investments. Most DVD participants will not even acknowledge the failures in the planning and alert potential purchasers of the incompatibility, preferring to obscure the omission as they did in not discussing CD-R incompatibilities with DVD-ROM.

Speed of technological change seems inevitable. Sometimes speed gets you where you want to go faster, but sometimes speed kills. Speed in product development and rush to market rather than well considered long-term planning has come on the scene to infect well-ordered CD marketing.

While the introduction of CD-RW will have little immediate sales impact, the negative long-term implications in the evolution of the 120mm family into DVD may indeed be grave unless clear-headed thinking becomes the norm rather than the exception. The options and the consequences of each of the many alternatives deserve a full and frank open examination so that the information technology consumer can be the judge of where we should go from here. It would be nice to think that media and hardware suppliers who heed the decisions of the marketplace and tailor their products accordingly will reap the benefits, while those who choose to go their own way drown in the sea of their unsold merchandise.

About the Author

Hugh Bennett, editor-in-chief of Hugh’s News, is president of Forget Me Not Information Systems, a reseller, systems integrator and industry consultant based in London, Ontario, Canada. Hugh is author of The Authoritative Blu-ray Disc (BD) FAQ and The Authoritative HD DVD FAQ, available on Hugh’s News, as well as Understanding Recordable & Rewritable DVD and Understanding CD-R & CD-RW, published by the Optical Storage Technology Association (OSTA).

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