The ABCs Of DVDs

Chances are you have a DVD player connected to your TV set and you might even have a DVD drive on your PC. But most PC DVD drives are ''read only'' devices that can be used to watch DVD movies or access data on DVDs, but not to create them.

That's starting to change. Just about all PC makers now offer the option of a DVD writer and several companies make DVD drives that you can add to your existing desktop or laptop PC.

If you're thinking of getting a new PC with a DVD writer or adding one to your existing machine, get ready for some alphabet soup. As much as I hate adding complexity to your life, I'm afraid it may be necessary to take a short course on the ABCs of DVDs.

Let's start with the basics. Contrary to what you many think, DVD doesn't quite stand for Digital Video Disc. The V stands for ''versatile,'' which is a pretty good description since DVDs can be used for video, but also for data, music or even still pictures.

Those DVD players people connected to their TVs along with most PC DVD drives are DVD-ROM players. ROM stands for ''read only memory.'' That's because those drives can only be used to read, not write DVDs.

And that leads to the really fun part -- devices that can write DVDs.

Currently there are five sets of letters to keep in mind: DVD-R, DVD+R, DVD-RW, DVD+RW and DVD-RAM.

DVD-R stands for DVD-Recordable which is the DVD equivalent to the CD-R discs that are so ubiquitous on PCs. A DVD-R disc can be written to once, but it cannot be modified, appended or erased after it has been created. DVD-R discs can be read in practically all PC DVD drives and on most (though not all) home DVD players. This is the format to use if you want to create a home video to play on the TV connected to a DVD player. DVD-R discs usually come as single-sided discs with a capacity of 4.7 gigabytes. You can buy DVD-R discs in quantities of 10 for about $3 each.

DVD+R is another recordable format which has the same capacity as DVD-R. This format will also play on most home DVD players.

The + obviously stands for ''plus.'' The - stands for either ''minus'' or ''dash'' depending on who you talk to.

Both DVD+RW and DVD-RW are formats for creating rewritable DVDs, which means they can be erased, modified and appended to. In general this is a good choice for data backup because you can keep adding to a disc with new data. Although DVD+RW discs are more expensive than the write-once DVD-R or

DVD+R, their ability to add new data makes them an economical choice for data backup.

If you ask someone in the DVD industry whether plus is better than minus, he or she will probably give you an earful. But ask someone from a competing camp and you'll get an equally compelling lecture as to why the other format is better. I wish I could give you an opinion on what I think it best, but these distinctions are pretty technical and, frankly, obscure.

Up until about a year ago, the leading PC maker advocate of DVD+RW was Hewlett-Packard while Compaq was the leading supporter of DVD-RW. As you probably remember, HP swallowed up Compaq and they're now both in the DVD+RW camp. Dell also supports the plus standard. While this isn't the death knell for DVD-RW, it certainly puts the biggest PC makers in the plus column. Still, a number of drive-makers are in minus camp, so I wouldn't rule them out.

DVD-RAM discs operate pretty much like a PC hard drive though slower. You can format them for PCs or Macs and copy files to them using the standard file copy commands. They typically come in a protective cartridge and cost nearly $20 each, but you can now find DVD-RAM discs without the cartridge for as little as $8.

Until recently, you had to pretty much commit yourself to one camp or another when you bought a DVD-writer, but there are now multi-format writers available that work with any format. I recently installed an Iomega SuperDVD Writer All-Format drive on my PCs and have successfully burned a variety of different types of discs. Iomega makes an internal drive that's available for about $250 as well as $329 external version that connects to a USB 2.0 port.

I'm not fond of taking apart my computer so I opted for the external version that's a cinch to install. The drive comes with a variety of software programs including HotBurn Pro for burning data discs and Sonic MyDVD for editing and burning video DVDs. I used the product to create a number of DVDs including one DVD+RW disc to backup my files and another DVD-R disc with a home movie from our digital camcorder.

The software that comes DVD writers can't be used to copy Hollywood movies. That's because those movies have copy protection technology designed specifically to prevent it. Of course, like all copy protection schemes there are ways around it, but that requires a separate piece of software such as DVD Copy Express from 321 Studios.

Whether it's legal to use such software is in dispute. The Motion Picture Association of America says that the mere existence of these programs is in violation of the Digital Millennium Copyright Act, while the companies that make this software along with some consumer groups argue that users have the right to make backup copies of DVD movies they have purchased.

By Larry Magid