When the CD-Rom was launched in the mid-1980s, many software publishers wondered how they would fill a disk that could store enough computer data to fill 500 floppy disks. At the time, most computer software was held on one or two floppies, so the new storage medium looked like technological overkill. Since then, of course, CD-Rom has moved into the mainstream.

Thousands of software titles are now supplied on CD-Rom and no self-respecting desktop computer comes without a built-in CD-Rom drive. But in an age of multimedia, the CD-Rom is showing its age, and software developers are now finding that it lacks the storage capacity they need. That is why more and more software titles are being published on two or more CD-Roms. So, enter the Digital Versatile Disk, or DVD.

DVD is a family of disks that includes some capable of carrying film titles (you may have seen them at your local music or video store). But the disk that is of interest to education is the DVD-Rom. From the outside, it is a CD-Rom with another name. It looks like one, is the same size as one - but that is where the similarity ends.

A DVD-Rom disk holds between seven and 30 times more data than a CD-Rom, thanks to some technical trickery and the fact that, unlike CD-Roms, DVD-Rom disks can be dual-layer (two data layers on the same side of a disc), double-sided or a combination of both.

DVD-Rom drives (which can also read CD-Roms, photo CDs and music CDs) have been launched by a number of manufacturers including Hitachi, LG, Philips, Panasonic, Sony and Toshiba. The drives typically cost between Pounds 100 to Pounds 150.

Computers with built-in DVD-Romdrives are thin on the ground (Timesells DVD-Rom PC systems for about Pounds 1,600 to Pounds 1,900, and some top-of-the-range Apple Macs include DVD-Roms), but this is expected to change next year.

What is more important, however, is a good source of DVD-Rom software. So far this has been hard to find, apart from UStitles such as the American Encarta. “Producing DVD-Rom software has proved to be difficult, so DVD-Rom titles are currently being bundled with computers,” says Tim Frost, editor of Future CD and DVD-Rom magazine. “But, having said that, if I was a school and could afford to buy a computer with a DVD-Rom drive, I would because you are future-proofing your purchase. DVD-Rom is going to happen.”

One of the first software companies to jump aboard the DVD-Rom bandwagon is Dorling Kindersley, which is planning to launch its first DVD-Rom title, World Atlas, before Christmas. The title includes hundreds of photographs, video clips and highly detailed maps. There is also a facility for “flying” around the world with real-time 3D graphics.

David Taylor, DK’s educational publisher, has tried the disk for himself:

“The sound and picture quality were amazing. I could fly over the Himalayas and all the views were crystal-clear. The potential for DVD-Rom to excite and interest children is huge because the graphics and video will hold their attention.”

Karin Murray, a producer at DK, says: “We’ve had a lot of requests from PC companies who want to bundle the World Atlas with their new computers. We’re currently experimenting with DVD-Rom to see how people react to it.”

Murray says potential DVD uses include adding several software titles to the same disk, reducing costs for schools. Another idea is to put a CD-Rom and full-length video programmes on the same disk, or to add navigational aids to video material, so users can jump straight to specific points rather than winding through lots of tape.

nother DVD format that should interest education is DVD-Ram. This is a recordable version of DVD and DVD-Ram disks (which hold between four and eight times more data than a CD-Rom) and can be used and re-used like floppies. Panasonic has launched the first DVD-Ram drive, the LF-D101U (Pounds 470).

DVD-Ram disks are stored in protective caddies and cost around Pounds 18 for a single-sided version, or Pounds 27 for a double-sided disk. DVD-Ram drives can also read DVD-Roms, CD-Roms and other types of compact disks, such as Photo-CD and Video-CD. But anyone thinking of buying a DVD-Ram drive should note that DVD-Ram disks cannot be read by today’s CD-Rom or DVD-Rom drives.

Another snag is that there are at least three other competing rewritable DVD formats under development. “As astorage medium, DVD-Ram offers great value for money, and it’s fine if you want to archive or store your own data,” Tim Frost advises. “But if you want to exchange data with others, then you should look at other formats like the rewritable CD.”

Few doubt that the computer industry will eventually migrate to DVD-Rom, although no one expects CD-Roms todisappear overnight. Despite their larger storage capacity, CD-Roms have not eliminated floppy disks. But will we be looking for something bigger than DVD-Rom in 10 years time? It is unlikely, as companies are already racing to develop DVD disks that can store at least double the amount of data of today’s disks.

DK www.dkonline.com 0171 836 5411

Hitachi www.hitachi.com 01628 585000

LG www.lge.co.krenglish 01753 500400

Panasonic www.panasonic.com 0500 404041

Philips www.philips.com 0181 6894444

Sony www.sony.co.uk 01932 816000

Time www.timecomputers.co.uk 0800771107

Toshiba www.toshiba.co.uk 01932 828828