Prepare for the DVD onslaught with DynaTek kit

Although there are few DVD titles, the drives are beginning to appear on the market
after years of wrangling over standards and copyright protection for DVD movies.

A DVD looks like a CD, but its data is recorded more densely by a shorter-wavelength
laser beam. The shorter wavelength means that smaller data bumps are detectible, and the
bumps are closer together.

DVD drives are being sold as kits that include bus master PCI interface cards. They
require a minimum 133-MHz Pentium system running Microsoft Windows 95 and having one free
bus master PCI slot and an open drive bay.

The bus master card contains the DVD interface and a Motion Picture Experts Group
2-compliant video decompression processor. MPEG-2 turns DVD from a data storage medium
into a publishing medium capable of squeezing a feature-length, high-resolution movie onto
a single side of the disk.

Business and government users plan to use the technology in their interactive training
videos. One disk can store a video with versions in as many as eight languages.

A DVD holds up to 17G of data. The initial crop of drive upgrades on the market all
support 17G despite the fact that no disk has yet been published at full capacity.

Current DVDs are holding only about 4.7G on a single side. A second layer can be added
to this side, doubling capacity, and the DVD standard permits packing both sides with data
in two layers each, reaching the practical maximum of about 17G.

As with CD-ROMs, a considerable amount of this maximum capacity is taken up by
directory structures and integrated databases that users need to find what they want out
of the vast sea of data.

But even with the index penalty, DVD gives tremendous storage capacity. Initial
applications so far are things like maps and telephone directory databases. The entire
U.S. telephone white pages fits easily on a single DVD, and the format eases searching
over current multidisk CD-ROM databases.

I tested DynaTek's DVD471TII kit, which included an internal half-height IDE drive from
Toshiba America Information Systems Inc. The kit also included a Quadrant International
Cinemaster Inc. IDE interface, an MPEG decoder PCI card, a cable, Win95 drivers and some
DVD titles.

You can mount the Toshiba drive horizontally or vertically, but I recommend against the
latter because vertically positioning disks in the tray is difficult.

The installation was straightforward. I made one call to the company's technical
support line at noon and finished in about two minutes. The only problems I'd expect other
users to encounter are sometimes buggy software drivers.

Six titles are supposed to ship with the DynaTek drive, including an electronics
encyclopedia. But because I was eager to test the drive, the company agreed to ship it
without all the titles.

I found the performance fast and the video smooth. No DVD was available, so I couldn't
do extensive performance testing. But the first-generation DVD drives likely have nearly
identical specifications.

Here is some published performance data. Note that it may differ for CD-ROM and DVD
played in the same drive.

The first-generation DVD drives cannot read CD-recordable disks.

Later versions are supposed to support CD-R via a second laser.

CD and DVD drives have different rotational speeds because DVDs have higher data
density.

In DVD mode, the drive turns about one-third as fast as it does in CD mode. This
maintains data transfer speeds low enough to let the interface keep up.

CD-ROM performance for the drive I tested about equaled that of an 8X drive. DVD
performance was equivalent, despite the fact that DVD standards call for much slower
rotation in first-generation drives. The data is closer-packed.

Although access times are a bit slower, data transfer is slightly faster than with an
8X CD-ROM drive.

The bottom line is that DVD works as advertised, but it won't cause a revolution in the
way we work. It is an incremental improvement, not a new paradigm for software
applications as CD-ROM was.

The CD made it possible to publish maps, photos and other massive databases on a cheap,
easily distributed medium. DVD brings a 28-fold increase in storage capacity; in contrast,
the move from floppy disk to CD-ROM brought a 400-fold increase and created entirely new
software markets.

Many CD databases probably will migrate to DVD and expand their features and the amount
of data they hold. Video DVD training will be similar to the laser disk training that has
been around for years. DVD will be more convenient and less expensive.

If you plan to publish agency data or training videos on DVD, or if there are
commercial DVDs that you need, there's no real reason to wait for the next generation of
DVD drives before you buy.

Prices for the drive kits are unlikely to drop significantly in the next six months
because MPEG-2 decoder cards are expensive. Don't expect SCSI DVD drives anytime soon.

PCs soon will come with DVD drives. Of course, the government already has an installed
base of Pentium PCs powerful enough to support DVD. So if DVD software titles appear as
fast as I expect, there will be a large demand for drive kits.

John McCormick, a free-lance writer and computer consultant, has been working with
computers since the early 1960s. E-mail him at powerusr@penn.com.