| It's an unfortunate tendency of some of those in the CD-ROM and multimedia industry to dismiss the CD family as a dysfunctional one. |
The CD/CD-ROM/CD-R/CD-RW extended family is a confusing one, certainly, replete with obscure consanguinity, incompatible siblings, kissing cousins, and crazy aunts and uncles. Add the new generation of DVD, DVD-R, and DVD-RAM, and interfamilial estrangement begins to look like a case of the Hatfields and McCoys instead of a generation gap.
The fact is, no matter how much distance-- or outright discontinuity--the DVD creationists place between the original disc and its descendants, DVD's lineage can be clearly traced: CD begat CD-ROM, CD-R, and CD-RW, and CD-ROM begat DVD, and DVD will beget DVD-R and DVD-RAM. That DVD evolved from CD cannot be disputed; the genes may be recessive, but over time, blood will tell. There will be throwbacks. All the more reason, then, to be familiar with the genealogy of the compact disc family.
And because compact disc in the real world is more than track sizes, byte counts, and file system formats, the famous books of standards for compact disc--Red Book, Yellow Book, Green Book, Orange Book, White Book, and Blue Book--tell only some of the story. In the day-to-day application of data served on silvered polycarbonate discs, application-specific formats have a history and lesson of their own. Not every book is the same weighty volume, and not every standard stands up to the same importance or use. There are (or were, rather, considering the outmodedness or irrelevance of some) standards that had more to do with target platforms than discs, such as MPC, CDTV, 3DO, and Sega; in other cases, a CD's format associated it mainly with operating systems, like HFS, Unix, or "hybrid." There is CD-3, a mostly forgotten name for the 8cm (3") small discs. And then there is Photo CD, one of the most successful proprietary "standards," and one that provided a graphics file system for CD; Video CD, on the other hand, represents a not as yet so successful format, for MPEG 1 video on disc.
At a time when the newest formats of compact disc shout for the latest moment of attention, and not-yet-born formats are being figured into business plans, an appreciation of what has come before may help those who look to the future generations to understand how best to get along.
Red Book, which defines CD-Audio, is the compact disc patriarch. Compact disc was created, after all, to be nothing more or less than a universal delivery medium for one type of content only, namely music digitized at 44,100 samples per second (44.1KHz) and in a range of 65,536 possible values (16 bits). Red Book, or Compact Disc-Digital Audio (CD-DA), was defined by Philips N.V. and Sony Corporation in 1980.
Data on an audio disc is organized into frames in order to ensure a constant read rate. Each frame consists of 24 bytes of user data, plus synchronization, error correction, and control and display bits. One of the first crucial things to understand about CD-Audio is that its data is not arranged in distinct physical units. Instead, one frame is interleaved with many other frames so that a scratch or defect in the disc will not destroy a single frame beyond correction. Rather, a scratch will destroy a small portion of many frames, all of which can be recovered.
Red Book disc itself is divided into three areas: Lead In, Program, and Lead Out. Each track's location, or address, is recorded in the disc's TOC, or Table of Contents, which is stored in the Lead In area of every disc. Because pressed CDs are read-only, the number and location of the audio tracks to be recorded is known in advance, and the TOC is written to the disc (or more accurately, to the glass master that will be used to create metal stampers to mold discs) in advance of writing the actual audio data. An audio disc can contain up to 99 tracks, which are stored in the Program area. After the Program area is the Lead Out area, which is simply 90 seconds of silence, or blank sectors. The Lead Out area on an audio disc is essentially just a ham-fisted way to let CD-Audio players know the music is over.
All of this technical detail about Red Book would be eminently forgettable, except for one small fact: the Red Book specification is the base case for all other types of compact disc. Every disc that came after Red Book in the CD family includes the specs of Red Book or refers to them. The physical, logical, and content description details of Red Book are the basic DNA of the compact disc, and everything that follows is either a specialization of these details, an adaptation, or a work-around. For example, the original strategy of data layout for safekeeping--interleaving files--shows up as a big factor in the fixed-length versus variable-length packet writing, in the current efforts behind the adoption of UDF (the Universal Disk Format) for CD-RW (CD-Rewritable). Packet writing for rewritability is just one instance of how all issues with compact disc come back to the father of all compact discs, Red Book. (Some argue, it is true, that the children may suffer for the sins of the father.)
Red Book was an entirely sufficient if not downright elegant solution to the need for a global medium for music that would play in a global music player. So what was wrong with Red Book for audio? Nothing at all. That doesn't mean that there aren't ways to embellish it, and it certainly didn't mean that ways were not found.
Some of the add-ons to Red Book include CD+G, CD Extra, hidden track, and CD Text. Each of these formats attempted to enrich plain old Red Book by adding elements of data other than music. In the case of CD+G, the "+G" meant graphics--primitive, slow-loading graphics, to be sure--but still something to look at while the music plays. CD Text is the newest wrinkle on the same concept as CD+G, allowing textual information such as lyrics, song titles, fan club information, and so forth to be stored in the same six normally unused bits in subcode channels R through W that were the method in CD+G. Graphics and text can be combined to make a CD+G Text application. Both CD+G and CD Text discs require players capable of retrieving and displaying the "hidden" information on a television screen.
Enhanced CD--which comes in a variety of strains, including Hidden Track, Mixed-mode, and CD Extra, a.k.a. CD Plus--are different ways to create pretty much the same thing, which is a disc that plays music on an audio player and computer data--video, text, still pictures, etc.--on a computer. Technically, the hidden track variety of Enhanced CD exploits a "loophole" in the definition of Red Book that allows 40 minutes or more of any type of data to be placed on the disc before the second subcode index point. Most CD-Audio players ignore this area and start playing at the second subcode index point, so this data is "hidden" from the audio player but can be accessed by a CD-ROM drive.
Mixed-mode discs consist of a track of CD-ROM (Yellow Book) data followed by up to 98 tracks of CD-Audio (Red Book) data. (This is something of a misnomer because Red Book audio is not precisely a Mode, although it is sometimes mistakenly referred to as Mode 0.) By definition, the format requires that the CD-ROM data be in the first track only, and this can be a problem in audio players, which will try to "play" the data.
CD Extra, the most recent attempt to meld the music and computer disc, relies on the multisession capabilities of Orange Book Part II (CD-Recordable) to place a Red Book audio session followed by a Yellow Book data session on the disc, since audio players can only see the first session. Most CD-ROM drives can see both sessions.
If Red Book is the father of all CD formats, Yellow Book is the mother. Red Book is actually the basis for and an integral part of Yellow Book, which defines CD-ROM, or Compact Disc-Read Only Memory, announced by Philips and Sony in 1983. CD-ROM was envisioned as a way to allow digitized content including but not limited to audio to benefit from the capacity, durability, and economies of scale that were rapidly making compact disc audio a big success. Yellow Book is the disc specification that gave birth to all the variations on a CD theme that make CD formats so versatile and, equally, so confusing.
Rather than rewrite the physical format, it was decided to adapt the physical format of Red Book for the storage of computer data. At its lowest level, Yellow Book specification for CD-ROM is nearly identical to Red Book, in that it retains the TOC, Lead In, Program area, Lead Out, and basic error correction. But the next level of Yellow Book organizes the frames defined in Red Book into sectors (98 frames, or 2,352 bytes, equals one sector) and adds another layer of error detection and correction. The extra error correction information, at 288 bytes per sector, plus 12 bytes of sync and 4 bytes of header, reduces the available sector space for user data to 2,048 bytes. Addresses of sectors are expressed as minutes, seconds, and sectors (MM:SS:SS). Yellow Book stops there, however, leaving it up to the CD-ROM developer to decide how to arrange sectors into logical blocks and logical blocks into files. And that is the first step into the complexity of CD, in the form of Mode 1 and Mode 2.
The Yellow Book specification defines two data structures: Mode 1 and Mode 2. The mode byte, which is included in the header field of a CD-ROM sector, describes the type of data contained in the data field. Mode 1 denotes CD-ROM data with Error Correction Code (ECC), which provides room for 2,048 bytes of user data and is the mode used to store data that is unforgiving of error, like computer programs or databases. Mode 2 denotes a sector with data stored without ECC, which provides more room (2,336 bytes) for user data, but which is typically used for data that is more tolerant of error, like audio, video, or graphics.
Most CD-ROM titles that hold databases, shareware archives, and computer programs are Yellow Book, Mode 1, and most CD-ROM discs published--period--are in "plain-vanilla" Yellow Book, Mode 1, ISO 9660 Level 1, for the DOS or Windows platform. These discs are also "accessible" on Macintosh and UNIX platforms, but they don't appear or perform like Apple or UNIX "natives." In spite of and because of this, the plain vanilla CD-ROM is the single most standardized data storage medium ever created.
Mode 2 is a way of interleaving sectors of data with extra error correction (Form 1) with sectors of data without extra error correction (Form 2), since Mode 1 does not allow unlike sectors to reside in the same session on a disc. The Mode 2 branch of the family tree is the show-biz side. CD-ROM/XA, Bridge discs (including Photo CD, Karaoke CD, and Video CD), and Green Book, or CD-i, are performing cousins to the computer CD-ROM. They have something in common besides Mode 2: they are all intended to play on dedicated consumer electronics platforms. Some, like Photo CD and Video CD, will play on either a computer or a dedicated platform such as a CD-i player, a Video CD player, or a dedicated Photo CD player (if you could find one).
In the early days of CD-ROM publishing, each developer used a different, incompatible file format for CD-ROM. This problem was addressed by the High Sierra Group, an ad hoc committee of CD-ROM developers who created the High Sierra Format, which was later adopted, with minor revisions, as ISO 9660, the logical file format for CD-ROM. There are three Levels of Interchange within ISO 9660: Level 1 requires that each file be recorded as a continuous stream of bytes, with filename conventions that are similar to the restrictions of DOS; Level 2 relaxes the filenaming conventions, among other things; and Level 3 is anything goes.
ISO 9660 was what gave rise to the claim "any disc plays in any drive" for CD-ROM. Unfortunately, the lowest common denominator approach in ISO 9660--Level 1--was not optimal for operating systems other than DOS. Apple's long filenames and data and resource forks, and UNIX's deep directory structures, did not fit well into the ISO 9660 Yellow Book mold. But even as the seemingly rigid Red Book could be adapted to do what it was never designed to do, so could ISO 9660 be adapted to suit the purpose.
Joliet, Rock Ridge Interchange Protocol, and Apple Extensions are three extensions of ISO 9660 that permit CD-ROM applications to retain cross-platform compatibility while performing like natives in their respective operating systems, whether Windows 95, UNIX, or Apple HFS.
And then there is hybrid disc, which is a disc that will work in two or more platforms, operating systems, or environments. Partitioned hybrids contain two or more separate partitions, each containing a complete set of data, each formatted for different operating systems. Shared Hybrid is a type of CD-ROM that also works on two or more operating systems, but each operating system accesses a shared data set. The disc contains one partition, containing the complete data set and all the files necessary for each operating system, but the DOS or Windows (or UNIX) user sees only the files pertinent to that environment, and the Macintosh user sees only the files pertinent to Macintosh. As if there weren't enough types of hybrids already, the term "hybrid" is also being used at times for a disc that includes Internet access along with an application that works locally. Sometimes this type of disc is called a Web hybrid, or CD/online hybrid.
| If something like El Torito is the strange unclue to CD, the Green Book specification for CD-i (Compact Disc Interactive) is unique. |
The beauty of a bootable CD is that the contents are not limited to using ISO 9660 or any other file system, or any hardware platform, for that matter. Because the operating system can be included on the disc, it can be created to suit the application. More than one operating system can exist on the disc, to take optimum advantage of whatever platform or system on which it is played.
Because of this chameleon quality of bootable discs, and because there is little widespread use of this strategy as yet, it's difficult to place Bootable CD in the genealogy chart. Best to leave it, perhaps, that El Torito is that eccentric uncle who shows up sporadically at family gatherings, but no one can quite remember exactly how he's related.
If something like El Torito is the strange uncle to CD, the Green Book specification for CD-i (Compact Disc Interactive) is unique in the CD family tree: it is the only specification which defines not only the disc and the contents, but an entire hardware and software system, a variety of special compression methods for audio and visual data, and a method of interleaving audio, video, and text data. CD-i has found a niche in informational and marketing kiosks, training, and portable interactive sales presentations, and is especially well suited for the presentation of high-capacity interactive multimedia applications to the noncomputer literate. CD-i is designed to interface with televisions and stereo systems. A $200 component called an FMV cartridge can be installed to add VHS quality, full-screen, full-motion video capabilities to existing CD-i players. A relatively recent development in CD-i is the addition of a modem, which allows a CD-i player to include a World Wide Web connection.
And where CD-i, or Green Book, went, soon followed CD-ROM/XA, which was an extension to Yellow Book specifications that was finalized in 1989 by, of course, Philips and Sony, but with help from Microsoft Corporation. CD-ROM/XA defined CD-ROM titles that shared certain common traits with CD-i titles, and especially the data interleaving, interactive capabilities, and a specific form of audio compression (ADPCM). The point of CD-ROM/XA was to describe a standard means for making multimedia data access from CD more efficient; interleaving audio and video data, for example, allows for better synchronization as long as the audio isn't Red Book, which is placed on its own track. CD-ROM/XA was also called a "bridge disc"--a disc that could be played on both a CD-i machine and a PC--because of this overlap.
While Photo CD--which can be played on CD-i and CD ROM drives, and so is a bridge disc--uses some part of the CD-ROM/XA specification, XA's time seems to have largely passed, with the creation and common use of interleaved data file formats, such as Windows AVI (audio-video interleave), solving some playback synchronization problems. Back in 1993, when Photo CD was still new to the market (it was defined originally a couple of years earlier by Kodak in conjunction with, of course, Philips and Sony), many CD-ROM drives couldn't read Photo CD discs, but that had to do with changes required in the drives' firmware to allow the drives to read multisession CD-Recordable discs. Although Photo CD hasn't caught on as a consumer platform, as Kodak had hoped, this format did cause CD-ROM drive manufacturers to add multisession-reading firmware changes that helped push multisession CD-Recordable widely into the market, which is Orange Book territory. One irony of Photo CD, to this day, is that it hasn't yet delivered the interleaving of audio and video data through Mode 2 that its base specification--CD-ROM/XA-- was largely all about.
| White Book, for those interested in knowing each and every embarrassing family detail, got its impetus largely from the Karaoke CD format. |
White Book, for those interested in knowing each and every embarrassing family detail, got its impetus largely from the Karaoke CD format, which continues to do well in the Japanese market for this form of entertainment device.
Orange Book, Part II--Part I was about MO or magneto-optical drives--added a whole new dimension to the CD family, which is the ability to create a disc in a desktop environment. The time of Orange Book's first publication was 1988, and the authors were, again, Philips and Sony. The ramifications for the CD clan could hardly have been more radical.
No longer a non-recordable read-only medium whose use was limited to applications restricted by the "lots of static information to lots of users" rule of thumb of replicated media, the recordable CD placed the power of publishing on disc in the hands of individuals with a personal computer and a CD recorder. It was as if the entire CD family had suddenly developed a genetic ability to fly, where once only walking was possible.
Not only was the disc now recordable, it was soon also appendable. The medium that was at first engendered only as a mass-produced vehicle for linear, read-only music of a very specific type was now capable of being used as a recordable and appendable medium for all types of random access data.
There was a price to pay, of course, for this specialized adaptation of the original disc, and unfortunately that price was paid in compatibility. The power of recording discs on the desktop was a package deal and brought with it the responsibility of making discs that would work. As the specialization developed, so did the uses to which the specialization could be put; this only increased the compatibility problem, even though improvements in reliability kept pace with the proliferation and specialization of the recordable disc. CD-Recordable grew into its new abilities, though, and has not only enjoyed conspicuous success in its own right, but brought increased distinction to its forebears.
| Adapting the ROM medium of CD for recording exacts several prices, including multimegabyte of overhead needed to work around the stamped-at-once original nature of CD. |
The latest, and some predict, the last specialization in compact discs is the CD-Rewritable (CD-RW) disc, which is specified in Orange Book Part III, released in 1994, again by Philips and Sony. And again, this new adaptation brings with it some compatibility issues in that a CD-RW disc is not compatible with existing CD players and CD-ROM drives because the existing laser optics that read discs aren't effective at discerning the pit and land-like marks in the phase change media. This self-limiting factor has caused some to find fault with the mutant CD-RW technology, saying that it will detract from the success of CD-Recordable, which is a mutant technology in itself but one to whose qualities we have become inured.
Arguably, CD-RW is neither a threat nor a competitor to CD-Recordable or any other CD format, but simply another extension of recordable capabilities and a far-flung extension of the original Red Book specification itself. If CD-Recordable allowed discs to fly, CD-Rewritable means the discs can now hover, too.
Interestingly enough, CD-RW has qualities that will take it forward into the next generation of compact disc--because CD-RW media use phase change rather than wavelength-specific dye technology, it is likely that future DVD drives will be able to read CD-RW discs. DVD drives will be able to read CD-R discs only if the drives are specifically equipped with two lasers, one for CD-R and one for DVD.
| CD-RW arrives at a cusp in the history of optical storage. The CD family is poised on the brink of a new era; alternative optical storage technologies are becoming more CD-like, even as compact disc becomes more floppy-like. |
Meanwhile, new magneto-optical technologies are undergoing a convergent evolution, moving away from traditional 5.25" and 3.5" form factors to a 12cm size. The MO7, as this new phenotype is called, is capable of containing 6 to 7GB. The MO7 will use the same optical system and the same wavelength laser--650nm--as DVD drives, and will be capable of reading CD as well as DVD discs, with the appropriate signal processing circuitry in place. After the format is finalized, by the end of 1997, it could rival DVD-R and DVD-RAM as a title development and replication input tool.
The next generation of compact disc, after a long period of gestation, is now beginning its birth trauma. The long wait, combined with great and perhaps unrealistic expectations of what it will be capable of, may have set the waiting world up for disappointment, at least in the short term.
The origin of DVD is fraught with as much drama as any good mythology of the gods, complete with elemental forces, colossal battles, and alliances and treachery. An often-asked question these days is, "Where did this DVD thing come from?", as if the format sprang fully formed from the foreheads of its creators. In reality, the story of DVD's emergence is a bit more convoluted. The first sign of a revolution in the making was when Nimbus Technology and Engineering, of Gwent, Wales, demonstrated a double-density Red Book (CD-Audio) disc containing two hours of MPEG 1 video at the Midem show in Cannes in January 1993. Nimbus chose the Red Book platform because at the time there was no other choice. Philips had yet to announce the Video CD standard or deliver the FMV cartridge for full-motion video on CD-i players, and CD-ROM, with its high overhead of error correction and detection, limited the capacity and playback speed of video data.
Optical Disc Corporation, another manufacturer of CD and videodisc mastering equipment, demonstrated double-density, White Book format Video CD played back on a Video CD player at the SMPTE (Society of Motion Picture Technicians and Engineers) show in October 1993. At the time, Adrian Farmer of Nimbus said, "Video is unquestionably the biggest, most universal entertainment market. It's far too important to be messed up over a controversy over standards." And the battle royal was on, as was the heat.
Traditional standards setters Philips and Sony found themselves in an embarrassing position; developers and content owners wanted a disc delivery medium for full-length movies, the ability of higher-density compact discs to contain and play back two hours of video on existing platforms had been demonstrated, yet there were no announced plans for an official Philips/Sony pedigreed high-density disc format. Philips and Sony objected to the illicit violation of the Red Book spec on the grounds of incompatibility. This may have been what led to Philips announcing, in early 1994--and in a very low-key way--that the waiting world could expect a new "color book" within two or three years, and that this book would define a high-density standard that could hold up to four times as much data as existing discs, including video. By December of that year, Philips and Sony had unveiled their proposed high-density format, eventually dubbed MMCD. In January 1995, Toshiba and Time Warner announced an alliance of companies that would support their own competing proposal for what they called SD, for Super Density disc.
The first eight months of 1995 were spent in a rancorous, dramatic, and highly public format war in which the two sides maneuvered for support from CD-ROM drive and PC manufacturers, Hollywood studios, and consumer electronics companies, while extolling the superiority of their respective formats and vowing to proceed with no compromise. By August 1995, however, a computer industry technical group convinced both Philips/Sony and the SD Alliance that a single format combining the best features of each proposal, and which would meet the needs of both the computer and entertainment industries, was the only acceptable solution. The result was a combined DVD format endorsed by a somewhat uneasy confederation of former bitter enemies: the DVD Consortium, composed of Toshiba, Matsushita, Sony, Philips, Time Warner, Pioneer, JVC, Hitachi, Thomson, and Mitsubishi.
DVD--originally standing for digital video disc, then digital versatile disc when the computer side of the market complained, and then simply DVD when anybody and everybody not suffering from tin ear complained--was envisioned as a universal medium that would eliminate, once and for all, the incompatibilities and cross-platform difficulties inherent to its ancestors. By basing the DVD specifications on a random-access, any-type-of-data model, DVD's genetic engineers hoped to eliminate the need for the hybrid, mutant, and specialized formats that were inevitable in CD. The theory was that a single DVD disc could be played on a music box, a television box, a computer box, or a game box, thus integrating the consumer electronics and computer market.
For anyone following CD's story since the first glimmer of Yellow Book, there should be no surprise that things aren't turning out as originally planned. Like so many theories, this universal medium theory took into account the requirements of the mutable elements--the data itself--but not the more immutable ones, such as the ways humans control and use the data. As a result, there are three versions of read-only DVD in the works: one for computer data, one for video, and one for music. The trade associations and producers of each kind of content are actively customizing the pertinent features of the three types of DVD, which will serve to estrange rather than integrate. Like compact disc, the physical format is identical for all types of read-only DVD discs. Unlike CD, the uniformity extends to the logical format and file system level. But at the application level, the similarities break down. Depending on how far the formats diverge, the ultimate result could mirror the tangled CD family tree, with not only hybrids and mutants, but half-bloods and freaks of nature.
DVD-Recordable and DVD-RAM, whose properties are even more problematic and conjectural today, will also be affected by the divergence of formats in the read-only DVD books. The DVD-Video crowd, for example, place primary importance on the control of content, while the definers of DVD-ROM emphasize the sharing and manipulability of content. Therefore, the outgrowths of DVD that place the power of recording and rewriting content in the hands of end-users are destined to be bones of contention. Of the little that can be known (since only specific companies' proposals and prototypes currently exist) about the capabilities of DVD-RAM, for example, one feature that stands out is that its various developers have already confirmed that first-generation DVD hardware will not be able to read DVD-RAM. This does not bode well for family harmony.
Unlike CD-R, which first appeared eight years after its progenitor Red Book was defined in 1980, DVD-R might well materialize within months of DVD-Video and DVD-ROM. According to Andy Parsons of Pioneer, the first DVD-R drives and media, at $11,000 and $50 respectively, will be available in June or July of 1997. Also unlike CD-R, DVD-R will not immediately offer a quantitatively analogous record-once medium for the development of DVD applications; the proposed capacity of first-generation DVD-R media is "only" 3.9GB, although that capacity could be doubled by using two-sided media.
First-generation DVD-R drives will be like first-generation CD-R in at least one respect, however: they will not offer incremental recording, only Disc-At-Once. While the smaller capacity is the consequence of technical limitations, the Disc-At-Once limitation is the result of the hardware not yet being fully coordinated with the specification. Although not much has changed, superficially, since the announcement of the pending final specification in June of 1996, version 1.0 was not now expected before February 1997.
DVD-R is conceptually and conceivably identical to existing CD-R--that is, the technology is based on blank media with a layer of organic dye polymer that is sensitive to a certain wavelength laser. It can be expected to perform like a chip off the CD-R block, allowing the desktop creation of DVDs for backups, title development, archiving, and distribution. It can also be expected to exhibit some less desirable bred-in-the-bone traits as well, especially in its infancy. For example, those who expect DVD-R's recording capability to make it the logical successor to VCR for video content are in for some disappointment. It's unlikely that the price or the politics of DVD-R will allow this to become a consumer item or a piracy platform. Add the cost of MPEG 2 video encoding hardware, plus full compliance with the copy protection encryption defined for its read-only siblings, and it's doubtful whether DVD set-top recording will ever be an affordable reality.
The most mysterious member of the new generation of discs is, like any conceived but not yet delivered creature, the subject of much conjecture. The proposed format is still under discussion by seven of its ten parents, namely Matsushita, Philips, Hitachi, Pioneer, Sony, Thomson, and Toshiba. Based on phase-change technology, DVD-RAM's expected capacity will be 2.6GB, but like many other aspects of DVD-RAM, this is subject to change. According to recent reports, the discussions are focused on designing the 2.6GB first-generation in order to maintain compatibility with the second generation. However, NEC has demonstrated a prototype disc camera using phase-change technology that is capable of holding 4.2GB per disc side, and claims that this has already been increased to 5.2GB per side--double the capacity of first-generation DVD-RAM.
DVD-RAM's due date is also only conjectural--the best clue to date comes from an executive in the Toshiba DVD division. According to Hisashi Yamada, "By the time it is available in the market, an overwhelming number of drives will be able to read it." In order to use the clues in this statement, one must be cognizant of a number of clues from other sources, including, first, that it is known that first-generation DVD drives and players will not be able to read DVD-RAM, and second, that only the most optimistic projections--such as Toshiba's--foresee the number of DVD drives exceeding the number of CD drives installed before the turn of the century.
When will the market see DVD-RAM? Today, the only sensible answer is, "Who knows?"
Before we dismiss the compact disc as failed technology whose mistakes we must try at all costs to avoid, we should consider CD successes. The compact disc family, in all its variations and flavors, has overcome seemingly insurmountable odds to beget a billion-dollar industry and give birth to technological innovation that has changed the face of computing and consumer electronics forever. It did so, in part, by not only enabling but in some cases forcing CD standards developers to create inventive ways of making the medium deliver all kinds of content in all kinds of environments. If this is an example of the "mistakes" of compact disc, DVD could arguably do worse than to emulate those mistakes.
Let's keep in mind, too, that when the compact disc was freshly invented, there seemed no end to which it could not be put, and no technological problem for which it did not offer an enhancement or solution. To assume that DVD will easily vault any future impediments without the proliferation of "adaptive" varieties of disc formats is not only naive but shortsighted. Once viewed as a universal format for digital information on disc--a veritable digital omnibus--the necessity for diversity in DVD formats and applications is steadily becoming more apparent.
Any new technology must offer some benefits over old if it is to become successful. The big mistake is in assuming that because DVD has the potential to deliver on the supposedly unmet promises of compact disc, that it automatically will do so. A related false assumption is that DVD has the built-in forward compatibility to accommodate any and all needs that may arise in the future.
In the effort to "avoid the mistakes we made with CD-ROM," the industry should remember one of the major factors that has made CD-ROM successful: the compact disc's diversity and flexibility, which exists even though the medium was never designed for what it is capable of today. Just as we never envisioned the demands we now put on compact disc to deliver all kinds of content in all kinds of environments, we cannot hope to fully envision what we will expect DVD to be capable of in the future. Operating systems, file formats, and hardware platforms will continue to evolve and change; we have no control over this. The best we can hope for is to create application standards that are flexible enough and sufficiently widely used so that future developments in these areas must include support for them.
While DVD is envisioned as the digital omnibus suited for all types of content--video, audio, and computer information--compact discs were originally designed around a very specific type of content. Compact disc, in its first incarnation as a vehicle for digital audio data, was rigidly defined not only as to the size of the pits, the spacing of the track, and the diameter of the disc itself, but included a precise definition of the type of digital audio content it would hold. This exact definition made it possible for compact disc to become widely accepted and inexpensive, which led to the demise of the vinyl LP and the decline of audio cassette. Luckily, within the confines of the compact disc specification, there is room for creativity and innovative ways to make a disc do what it was never intended to do.
As it turns out, CD has not done so badly. If DVD does as well as CD, warts and all, we'll be in great shape.
Eastman Kodak Company
Kodak Park Gerber,
460 Buffalo Road,
Rochester, NY 14652;
800/235-6325;
http://www.kodak.com![[LiveLink]](/file/36067/SIGCAT 97 - Conference on Convergence.ISO/Docs/webcd.gif "[LiveLink]"){kind=small}
El Torito - Phoenix Technologies
2770 De La Cruz Boulevard,
Santa Clara,
CA 95050;
http://www.ptltd.com:80/desktop/specs.html
Hitachi Home Electronics, Inc.
401 West Artesia Boulevard,
Compton, CA 90220;
800/369-0422; 213/537-8383; Fax 213/515-6223;
http://www.hitachi.com
JVC Information Products Company
17811 Mitchell Avenue,
Irvine, CA 92714;
714/261-1292; Fax 714/261-9690;
http://www.jvcdiscusa.com
Matsushita Electronic Industrial
One Panasonic Way 3C-7,
Secaucus,
NJ 07094;
201/392-6067; Fax 201/348-7579
Microboards of America
1480 Park Road, Suite B,
P.O. Box 846,
Chanhassen, MN 55317;
612/470-1848; Fax 612/470-1805;
http://www.microboards.com
Microsoft Corporation
One Microsoft Way,
Redmond, WA 98052;
206/882-8080; Fax 206/936-7329;
http://www.microsoft.com
Mitsubishi Chemical America, Inc. Company
445 Indio Way,
Sunnyvale, CA 94086;
800/347-5724; Fax 408/481-9488
Nimbus Technology and Engineering
Llantarnam Park,
Cwmbran, Gwent,
Wales, NP44 3AD;
+44 1 633-877121; Fax +44 1 633-876131
Optical Disc Corporation
12150 Mora Drive,
Santa Fe Springs, CA 90670;
310/946-3050; Fax 310/946-6030;
http://www.optical-disc.com
Panasonic Communications & Systems
Two Panasonic Way,
Panazip 7D-2,
Secaucus, NJ 07094;
800/742-8086; 202/348-7000;
http://www.panasonic.com
Philips Consumer Electronics
P.O. Box 80002, Building SWA-1,
6500 JB Eindhoven,
Netherlands;
+31 402 736-409;
Fax +31 402 732-113;
in the U.S., 800/845-7301; 800/234-5484;
http://spider.media.philips.com/media/
Philips Electronics North America Corporation
One Philips Drive,
P.O. Box 14810,
Knoxville,
TN 37914-1810;
423/521-4316; Fax 423/521-4345;
http://www-eu.philips.com/pkm/laseroptics/dvd
Pioneer New Media Technologies, Inc.
Multimedia and Mass Storage Division,
2265 E. 220th Street,
Long Beach, CA 90810;
800/444-6784; 310/952-2111; Fax 310/952-2990;
http://www.pioneerusa.com
Ricoh Corporation
3001 Orchard Parkway,
San Jose, CA 95134-2088;
408/432-8800; Fax 408/944-3312;
http://www.ricoh.com
Sony Electronics Inc.
1 Sony Drive,
Park Ridge, NJ 07656;
201/930-1000; 800/222-SONY;
http://www.sel.sony.com
TDK Electronics
12 Harbor Park Drive,
Port Washington, NY 11050;
800/835-8273; 516/625-0100;
http://www.tdk.com
Thomson Consumer Electronics
10330 North Meridian Street, Indianapolis,
IN 46290;
317/587-3000;
http://www.thomson-multimedia.com
Toshiba America Information Systems Inc.
Disk Products Division, 9740 Boulevard, Irvine,
CA 92718;
714/457-0777;
http:www.toshiba.com/tacp/SD/
Warner Media Services
3601 West Olive Avenue,
Suite 210,
Burbank,
CA 91505;
818/953-2941
Dana J. Parker is a Denver, Colorado-based independent consultant and writer. She is a Contributing Editor for EMedia Professional and also the regular columnist for Standard Deviations. She is the co-author of CD-ROM Professional's CD-Recordable Handbook (Pemberton Press, 1996), and is writing a book on DVD for Prentice Hall Technical Books.
Comments? Email us at letters@onlineinc.com.
Robert A. Starrett
The main factors in the this recent acceptance are plummeting CD-ROM drive costs, the proliferation of "multimedia" titles that add whiz and bang to information, and the wholesale shift in software distribution from multiple floppy disk sets to CD-ROM. On the CD-Recordable side, falling recorder prices also help, along with affordable media and substantial improvements in the functionality, versatility, and usability of CD recording software. Arguably, the recognition of desktop CD-Audio capability has contributed to the expansion of CD-R as well.
Of course, CD-R--and even to some extent still, CD-ROM--falls short of the holy grail of all marketers, which is "A component in every home." Some early attempts, such as Commodore's CDTV and Tandy's VIS came and went with sparse fanfare, little acceptance, and little market penetration; only CD-i, of like clan, has survived, largely due to the economic staying power of its parent, Philips NV.
Philips' latest incarnation of CD-i is Web-i, providing users with the ability to "Surf the Net on your TV." It remains questionable whether people have ever wanted their televisions to be anything more that a passive mode of entertainment, however. A large portion of the public's knowledge of world and national events is limited to what has been scripted for Dan Rather, with some short accompanying film footage, and newspaper readership has dropped alarmingly, with the newspapers that are read increasingly the print version of the evening news, in the form of USA Today with its color pictures, its "never in depth" format, and its tabloid-like misreporting of such issues as missing children (two million a year according to USA Today, 30,000 according to the FBI).
It is hardly a stretch to suggest that obtaining in-depth information--which, indeed, is available on the Web--is not the goal of the average TV user. A recent survey of 7,000 home consumers showed that four percent planned to purchase an Internet TV device, three percent were undecided, and 93 percent had no intention whatsoever to turn their tube into an educational or informational apparatus by connecting it to the World Wide Web.
If CD/Web/TV hybrid devices seem to hold little promise for wide market success, the original CD-Audio format stands in as an irrefutable success. Some argue that DVD-Video--the movies on a disc format--can be a like success. But DVD's success, of course, depends on a number of factors, including the cost of DVD movie players, the number of readily available titles, and the market's perception that there is compelling reason to replace the huge installed base of VCRs and the tens of thousands of videotapes. One reason for the VCR's popularity is price, where a low-end player/recorder costs a little over $120, and a standalone player can be had, with the right sale, for about $65. Recorded VCR tapes sell for $5 to $20 and can be rented for a buck or three. Unless and until DVD players cost under $200, DVD titles under $20, and local video store inventories contain thousands of quality titles, DVD movie players will be at best a toy for the affluent and electronically curious, and not another significant component in America's audio visual stack.
With the personal computer becoming more and more a part of everyday life, not only in the office but on the road and at home, the opportunities for sales of CD-related products represent the real growth market. The popularity--indeed necessity--of the medium for computing chores is clear: any off-the-shelf computer has a CD-ROM drive in it, and today, a CD recorder can be purchased for the same price as a top-quality CD-ROM drive three years ago.
Of course, it is the economies of scale that brought CD-ROM drive prices to their present levels, where their costs to OEMs and VARs are only in the tens of dollars, and the economies of scale will do the same for CD recorders. Within the next two years, personal computers will come with CD recorder/readers as standard equipment, and the read-only CD drive will be only used as a networked resource, racked by the tens and hundreds, or as additional drives in personal desktop systems or within multichangers.
The impetus for the recorder as standard equipment movement is not simply price but ease of use. Packet writing-enabled recorders can, in conjunction with software such as Adaptec's DirectCD, become a useful peripheral for the average user. Let's face it: explaining why you cannot use a hyphen in a filename is no way to build CD-R sales, especially in the broader market where the device will be used for data storage and personal publishing. The best way to kill the potential in the CD-R market would be to insist that every possible user be well-versed in things like PMA and PCA, buffer underruns, the distinctions of real and virtual writing, or the structure of tracks and sessions, or the definitions for DAO, TAO, and on and on and on. To expect the average user to understand and accept--not to mention, care--about such things as part of everyday computing is just plain silly.
Drive letter access for writing files to CD is what will launch CD-Recordable into the mainstream. A nod from Microsoft Corporation that results in the inclusion into a future version of Windows of drive letter access for writing to CD will seal the wide market. Seamless, transparent, stable, economical, and interchangeable: this is the future of CD-Recordable in the personal computing realm.
Of course, the original raison d'être for CD-R--prototyping of published titles and internally distributing corporate data--do not disappear, but rather will continue to grow. But CD-R as a personal or network backup medium has gotten a big boost from full-featured backup software from backup leader Seagate Software in the form of Seagate Backup, and it is likely that Cheyenne Software and other backup software companies will inevitably follow with CD-R functionality added to their already mature tape products. On the personal backup side, small-capacity, low-cost tape drives will lose market share to low-cost CD recorders which, enabled with packet-writing capability, can perform the backup task more efficiently and reliably and with better media stability and longer media shelf life.
This year will see the final barriers fall to full acceptance of CD as a secondary computer storage medium. CD-Rewritable (CD-RW), properly implemented, will erase, one might say, the distinctions that have separated the CD medium from other data storage technologies such as magnetic disk, magneto-optical, and phase-change optical storage. It has been assumed, projected, and pundited that CD-RW will enter the market in 1997 at a higher price point for both mechanism and media, relative to CD-Recordable devices, but some of the top participants have recently suggested that price points for CD-RW will match like-performing (except for the rewritability, of course!) CD-R drives. As CD-RW follows the trail to acceptance among the computing public, the economies of scale will result in further declining prices and broader acceptance. The issue of CD-RW's inability to be read by today's CD-ROM and CD-R drives will be resolved by Multiread, the CD-RW Gang of 5's definition of inexpensive changes needed in new drives (automatic gain for the pick-up head, mainly); it is inconceivable that companies the likes of Ricoh, Hewlett Packard, Philips, and Sony will bite the hand that feeds them by not moving heaven and earth to see Multiread in a multiplicity of drives. This year's projected shipment of new CD-ROM drives is somewhere in the 60 million range; if half are Multiread, CD-RW will have a big reader base by end of 1997.
CD-R and CD-RW will not replace tape backup applications that are beyond the capacity of one disc, and large capacity 4mm (DAT), 8mm (Exabyte), and DLT (Digital Linear Tape), for example, will continue to be the medium of choice for these backup applications. Competition in big backup will have to come from DVD-R and DVD-RAM with their larger single disc-capacities.
Speaking of DVD and all of its flavors, there is a bright future for the medium, and not just potentially, but to some degree, inevitably. But with DVD pricing in all areas still uncertain and with the recordable and rewritable versions still, in my estimation, two years or more away, the impact on CD-R and CD-RW technology remains too uncertain to predict. We have seen the CD medium, with all its limitations, adapt to cover so many contingencies and new applications that penning any obituary based on the current state of DVD confusion is premature. Like a life form that is able to change with the worlds around it, CD in all its flavors and colors will continue to adapt to and brave the climate and hazards of its world.
Some see the introduction of DVD-Recordable as a threat to CD-R, just as others have speculated that DVD means CD-ROM will shortly disappear. Others forecast a battle royale between CD-RW and DVD-RAM, with consequences that threaten the hard won victories now claimed by CD-R. Announcements and introductions of new technologies often have an inhibiting effect on current similar technologies as they cause users and purchasing departments to slow or reconsider their decision-making in acquiring those technologies. And it is only natural that those companies introducing the technology are likely to go overboard and be overblown in their marketing and advertising materials. Any discussion of the downside to new products, of course, tends to wait for analysis by independent, disinterested sources, or a counter-offensive from competitors not using the technology.
But so it has always been, and the market more often acts in its own best interests. Will CD-ROM sales fall quickly under an onslaught of DVD-ROM drives? The question may well be moot, in that DVD-ROM drives can be--will be--readers for CD too. Will CD-R evaporate as CD-RW comes to market? All plans for CD-RW postulate drives that read CD-ROM, read and write CD-R, and read and rewrite CD-RW, which hardly suggests that CD-R is finished. Will CD-RW's backward compatibility problems with old CD-ROM drives mean another stillborn format? Ask Panasonic and its PD drive partners how they like this "worst case" scenario themselves, and look to see if "MultiRead," the specifications for new CD-ROM drives to enable reading of phase-change-based rewritable discs, catches on. And will DVD-R and DVD-RAM push CD-R and CD-RW away from the glorious markets hoped for, supplanted by the next generation high-density compact disc formats? The long answer has something to do with timeline for implementation, which today includes solving some basic definitions, never mind shipping product.
The short answers to these questions about CD and its still-evolving progeny is, "Who cares?"
Already, we've seen the CD "orphan" adopted on a scale larger than many would have imagined. Already, we've seen CD prove itself a crafty and malleable addition to the computer storage family. As CD continues to grow and mature, the right expectation is that it will continue to evolve and change and be the envy of mass-storage parents everywhere.
Comments? Email us at letters@onlineinc.com.
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.
Comments? Email us at letters@onlineinc.com.
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