Classic Computer Magazine Archive COMPUTE! ISSUE 144 / SEPTEMBER 1992 / PAGE A4

Multimedia players. (CD-ROM multimedia standards)
by Mark R. Brown

It's a silver disc just five inches across, it's as thin as a dime, and it shines like the rainbow glasses you bought at the novelty shop when you were a kid. But on that shiny, micron-thin surface is stored more information than you can squeeze onto a library bookshelf. It's called a compact disc, and you probably already own dozens of them filled with music by Bach, the Beatles, or Nirvana.

CDs have taken over the music-recording industry, surpassing cassettes and killing vinyl LPs in just a few short years. Why? Because they're better. They survive scratches, smudges, and other physical abuse better than cassettes or LPs do. They're also smaller and easier to stack and handle. But, best of all, the music on a CD isn't stored as an analog signal, which is prone to noise and distortion. Instead, CD audio is stored as digital data, which is read by a laser beam and converted into analog music by the player. The quality of the data on the disc is always the same--inviolate, impervious, and unchangeable.

A standard CD is capable of storing over 600MB of data. When that data is comprised of high-quality digitized sound, as it is on an audio CD, it translates into about 70 minutes of music. But there's nothing that says that the data on a CD has to be music. Like any digital storage medium, a CD is indifferent to what kind of data is stored on it. CD data can represent anything that can be transformed into a stream of binary bits. In fact, the same technology is used to create video laser discs. The only difference is that laser discs are bigger and spin faster, because a video signal is much more complex than an audio signal.

Of course, a CD can also be used to store computer data. But there's one good reason CDs have been slow to gain acceptance as a personal computer storage medium: They're a read only technology. That's why computer CDs are called CD-ROMs. The ROM appellation means the same thing it does when applied to memory chips: Read Only Memory. You can't add data to a CD, modify the data that's already there, or even delete data you no longer need. CD data is burned onto the disc at the factory, and that's that.

Still, there are many reasons why you might want 600MB of read only data in such an easily handled format. Reference materials are good candidates for CD-ROM. After all, you don't need to modify encyclopedia articles or dictionary entries--you just want to look things up. Educational programs are another good prospect for the CD-ROM format--teachers seldom want students to be able to modify the lesson plans! Multimedia presentations are also good CD-ROM candidates--you don't change a television show as you watch it, and the same is true for most multimedia "shows." Finally, many commercial games have gotten so complex that they're shipped on a fistful of disks and require hard drive installation before they can be played. Shipping such games on CD-ROM saves time, money, and player frustration.

But until recently, personal computers equipped with CD-ROM drives have been a rarity. There are three good reasons for this. One is the chicken-and-egg problem that haunts the introduction of every new technology. Users don't want to invest in hardware until there's compatible software; software publishers don't want to release software until there's an installed hardware base capable of running it. Overcoming new technology inertia always requires some time, and CD-ROM has finally reached the point where the inertial resistance is nearly gone.

The second issue is cost. New technologies require new hardware and software development tools, new production facilities, and even new packaging. It takes time and money to retool. Fortunately, CD-ROM is riding on the coattails of the audio recording industry. Because audio CDs have been so successful, CD drives, duplication, packaging, and so on are now inexpensive and easily obtained.

Lack of standards is the third reason it's taken so long for CD-ROM to get established. Until now, it has been necessary for each CD-ROM software publisher to write its own hardware drivers, its own indexing programs, and its own audio and graphics display routines. But all that's changing, and changing fast.

Too Many Standards

If anything, the CD-ROM marketplace now suffers from too many standards, because the last 18 months have seen the introduction of not one, but three standard CD-ROM formats.

The first to be talked about was CD-I, a CD-ROM standard hashed out by Philips, the huge international megacorporation, with the help and support of almost every major player in the electronics industry from Sony to Magnavox. But CD-I took a long time to get from the drawing board to the marketplace. Though Philips showed CD-I demonstration units at trade shows several years ago, it took some real competition from Commodore before CD-I products began appearing on store shelves.

When Commodore introduced its CDTV player, the CDTV format became the first CD-ROM standard actually to reach the marketplace. Based on Amiga technology, CDTV took an astonishingly short time to make the transition from concept to consumer. Though it initially suffered from a lack of promotion and an uninspiring crop of hastily translated software titles, CDTV did get the industry's attention. Philips and Magnavox scrambled to catch up, but it was still almost a year before they were able actually to field a competing CD-I box.

CDTV and CD-I are both standalone multimedia players. They're also computers, but they keep their computer power hidden inside boxes that look like home audio equipment. For those who prefer using a "real" computer, there's yet another new CD-ROM standard. A multicompany committee led by Microsoft has hashed out what it calls the MPC, or Multimedia Personal Computer. Based on the MS-DOS/ Windows platform, MPC is endorsed by over 40 computer manufacturers, including Tandy, NEC, and Zenith.

Is there room in the marketplace for all of these new standards? Before we can answer that question, we need to take a look at their capabilities.

Hardware Standards

CDTV is built around a modified Amiga 500 motherboard equipped with 1MB of Chip RAM and a CD-ROM drive. It comes with a wireless remote that's somewhat reminiscent of a Nintendo game controller with the addition of a tiny numeric keypad. Front panel buttons control the basics of playing audio CDs, though the remote allows more CD play options. The remote is also used as a game controller and multimedia button selector. There's a removable panel on the front of the CDTV box that conceals a slot for a battery-backed RAM or ROM card. SimCity, for instance, uses a RAM card in this slot (or an Amiga floppy drive) to store saved games.

The back of the CDTV case reveals the unit's true power, because located there are connectors for a keyboard, mouse, and floppy disk drive, as well as computer-standard parallel and serial ports. An optional $200 expansion kit provides a keyboard, wireless mouse, and floppy drive, which expand CDTV into a full-blown Amiga computer. Though Commodore initially downplayed these connectors, fearing that they would scare off the consumer, it has now rightly concluded that CDTV's computer expandability is the number one reason to buy it.

There's no standard Amiga expansion slot, so CDTV users can't currently add expansion RAM or a hard drive. But there's a CDTV-specific slot on the back of the case that Commodore says could eventually hold SCSI, network, or other expansion cards.

>From the front, CD-I looks like CDTV, but what's inside is significantly different. CD-I is an unexpandable, stand-alone box. There are no computer connectors on the back. The wireless remote sports a tiny joystick. The computer chip inside CD-I is similar to the 68000 inside CDTV and runs at about the same speed. But CD-I units can't communicate with floppy drives, keyboards, or hard disks. That's just not CD-I's design philosophy. CD-I is built to run consumer software--games, multimedia shows, and reference works--and nothing else. Philips and its consortium believe that's what the consumer wants.

MPC, the Multimedia Personal Computer, is based on an IBM PC platform. The MPC standard requires at least an 80386SX PC with 2MB of RAM and a 30MB hard drive. It also requires an approved stereo sound board, such as the Sound Blaster. The graphics hardware must be capable of displaying 640 x 480 screens in 16 or 256 colors. This is the minimum hardware configuration. But the MPC software standard requires Windows and the Windows Multimedia Extensions. With all this running in the background, an MPC system should contain even more RAM and a bigger hard drive than the minimum requirements demand.

CDTV is selling on the street for under $600, as is CD-I. A minimum MPC system can set you back about $3,000. All of them are clearly aimed at different markets, though there is bound to be some competition for users, as well as for developers to create the titles that run on these platforms.

Audio Aesthetics

The obvious place to start comparing system features is with audio. After all, CDTV, CD-I, and MPC are all based on audio CD technology, and all three play stereo audio CDs, just like a standard audio CD player.

CD-I and CDTV also play CD+Gs, audio CDs with a special graphics track recorded alongside the music. There are only a few of these discs available, but some of them are very impressive productions. These CD+G titles use slowly scrolling still graphics, not animations or video. The data bandwidth of a CD simply isn't wide enough to allow anything more. CDTV also plays CD+MIDIs , which control a MIDI keyboard to play along with the CD audio. These discs are currently almost nonexistent. To date, I've seen only two, and one of those was a proof-of-concept demo disc.

Besides high-quality CD stereo audio, all three CD-ROM standards also support slower, AM radio-quality digital sampling rates. These allow up to 12 hours of narration, sound effects, or other lower-quality sound to be squeezed onto a single CD. These audio formats are all that CD-I provides. CDTV and MPC, however, allow programmable control of their internal audio circuits. This means that an MPC disc can preload data to control its sound board, and CDTV can preload anything that the Paula audio chip can interpret as sound. Each of them, MPC and CDTV, supports its own digitized sound standards--RIFF for the MPC and IFF for CDTV--and each can play music or sound effects independent of its CD playback circuitry. This CD-independent sound programmability gives a definite audio edge to both CDTV and MPC.

Graphic Differences

The graphics capabilities of any video-generating device are inexorably tied to the quality of the display monitor. CD-I and CDTV are both intended for home use, so both adjust their graphics output to the lowest common denominator: broadcast television. Each has an RF output for connection to a television's antenna inputs. They're both equipped with RCA jacks for composite video output, and both have S connectors for high-quality separated Y/C (S-VHS) video out. CDTV also comes equipped with a standard Amiga RGB output port; CD-I doesn't have it. RGB video out is all you get with MPC-standard machines--they simply aren't "home video" compatible. If you want to record MPC video output, you need to add an external RGB-to-composite converter box or a special Super VGA card that has composite video output, a rare feature in the PC universe.

All three standards offer similar graphics resolutions. MPC is perhaps the most limited, with a 640 x 480 resolution in just 16 or 256 colors. Of course, the video hardware in most MPC systems is capable of more variety, but this resolution and this number of colors are the two "official" standards stipulated by the MPC software. CD-I can build screens in resolutions ranging from 384 x 240 to 768 x 480 and can do so with 64, 128, 256, or a full 16 million colors. CDTV can do anything a standard Amiga 500 can do, which means resolutions similar to CD-I's but with fewer colors, a maximum of 4096. (Commodore has shown a CDTV unit incorporating Digital Creations' DCTV color enhancer; this custom CDTV can handle the full range of allowable NTSC colors. It may be made available as an add-on option, and future CDTV units may even ship with built-in DCTV capability.)

CDTV also features a video slot on its back panel, which allows you to plug in a software-controllable genlock card. Neither CD-I nor MPC supports an integral genlock, though MPC will make such capabilities available via add-on cards and drivers.

CD-I is capable of home television-quality video output; MPC generates computer-quality graphics. Only CDTV is equipped to handle both right out of the box.

Animation and Video

All three of these hardware platforms are capable of loading and running animations from CD-ROM. CDTV, of course, features the Amiga custom chip set with its integral blitter, which makes for quick and clean animations. CD-I software has also demonstrated its ability to deliver very respectable animated graphics. MPC computers are at the mercy of their respective video cards, most of which are capable of fair animation. But the MPC standard itself defines no animation file format. Developers are currently relying on a stand-alone Windows player for Macintosh-generated anims.

Full-screen, full-motion video is currently out of the question for any CD-ROM-based machine. Video frame rates are simply too high and require more data than CD-ROM can deliver. But all three standards promise to add MPEG data-compression chips eventually, which will allow full-screen real-time video. Of course, that will eat up a lot of CD-ROM space, and even with compressed data, 600MB of storage will no longer seem like enough.

In the meantime, CDTV has an edge with its CDXL technology, which lets CDTV pull data from the CD-ROM at the highest possible speed. It's enough to let CDTV display 15 frame-per-second video with audio at one-fourth screen size. Used cleverly, CDXL is pretty impressive and is certainly the closest any of these standards can come to delivering full video at this time. (Editor's note: At press time Philips publicly exhibited their MPEG technology for CD-I, which allows fullscreen, full-motion video. MPEG add-ons should be available soon for all three CD platforms.)

Software Selection

CD-I, CDTV, and MPC all suffer to some degree from the chicken-and-egg syndrome we mentioned before. CD-I has perhaps the smallest software base so far, though almost every CD-I title that's available shows extremely high quality. MPC developers have also been slow in tooling up, though there seem to be quite a few commitments from early CD-ROM developers to create MPC-compatible versions of their reference titles.

Believe it or not, CDTV may have the largest installed base of software available right now. There are about 100 CDTV titles now on the market, ranging from reference to entertainment. Of course, many of these are shovelware, Amiga titles that were quickly converted to run on CDTV. Still, many of them are of excellent quality.

CD-I machines can run only CD-I titles. MPCs can run all MS-DOS and Windows software in addition to MPC software. CDTV owners can spend $200 on a keyboard, floppy disk drive, and wireless mouse and then run any AmigaDOS 1.3-compatible Amiga software (as long as it will run in 1MB of RAM and doesn't require a hard drive). That's a lot of titles. However, CDTV isn't yet AmigaDOS Release 2 compatible.

Obviously, MPC and CDTV have a clear advantage over CD-I in the software category.

The Bottom Line

CD-I and CDTV cost about the same, and MPC costs a lot more. For a couPle of hundred bucks, CDTV can be expanded into an Amiga computer. When you look at the price/performance ratio--always Commodore's strong suit--there's no comparison. CDTV wins hands down. But is that all there is?

CDTV needs the chance to build a larger installed base if it's going to succeed as it deserves to. That means promotion. It means Commodore is going to have to convince developers to develop for CDTV. One big help would be for Commodore to release the long-awaited CD-ROM drive for the Amiga 500, as well as versions for the 600, 2000, and 3000. A larger installed hardware base would drive software development, which would, in turn, sell more CDTV units. (The Amiga 500 CD drive may be available by the time you read this.)

CDTV is a single machine from a single company. CD-I and MPC are both standards hashed out by committees made up of representatives from many powerful electronics companies. While that doesn't necessarily mean the sounding of the death knell for CDTV, it does mean that the folks at Commodore have their work cut out for them. They're going up against a lot of savvy competitors.

CD-I is, I think, too weak, too unexpandable, and too specialized to really make it in the consumer market. Philips is putting a lot of money behind it, but I think most consumers will see its limitations and either forget about multimedia players entirely or buy an MPC or CDTV unit.

MPC has some shortcomings, not the least of which is the fact that most PCs and PC clones now in the field are too wimpy to be upgraded to meet the minimum MPC hardware requirements. That means a new computer for users of older PCs, which in turn means lots of cash outlay. While that may not deter big business from investing in the MPC standard, it will slow down a lot of other end users who'll find they can spend $2,000 on either a slow 386SX-based MPC unit or on a blazingly fast, CD-less 486/33 PC.

So CD-ROM multimedia standards are still in a race, and it's too close to call. With its expandability, its software base, and its excellent price/performance ratio, CDTV has at least a good chance of competing hard. Now let's see who takes the gold.

Editor's note: At press time, it seemed as if Commodore was ready to launch a powerful salvo in the CD-ROM war The company was almost ready to ship the new A570 CD-ROM drive for the Amiga 500, which essentially turns an Amiga 500 into a CDTV work-alike. (For more details, see last month's feature.) If a quarter of all Amiga 500 owners purchase the A570 (and surveys in the U.K. show that interest is quite high), then there will be almost a million new consumers of CDTV discs. This potentially huge market could initially cause the CDTV software market to leap that for the MPC units, which might interest big-name developers in CDTV. The timely release of the A570 drive for the 500 in the U.S. and Europe, as well as CD-ROM drives for other Amiga models, and their acceptance by the Amiga community, could make or break the Amiga/ CDTV CD-ROM software market.

Commodore said that the specifications of the A570 hadn't been finalized as we went to press. However, preliminary units included a CDTV-compatible CD-ROM drive, 256K of ROM, and room for 2MB of expansion memory. Also, there are provisions for adding a SCSI hard drive. However, there's internal room for only a tiny laptop-sized hard drive, and most of those use IDE interfaces. This expansion potential is especially important, since the A570 doesn't have provisions for passing through the expansion bus. To be fully CDTV compatible, you'll need 1MB of Chip RAM. Commodore previously disallowed the 500 Chip RAM modification; the A570 may force the company to change that policy.