Computer manufacturers said out with the old and in with the new, but with the constant flow of computer upgrades, finding a place to put the old has become a problem.

A study by the National Safety Council estimates that in the United States, 20.6 million personal computers became obsolete in 1998. Eleven percent of those, 2.3 million computers, were recycled. Another 1.3 million were refurbished, mostly by charities. The rest are stashed in attics and the back corners of closets.

Disposing of an old computer is not as simple as putting it out with the trash. Many computer owners are reluctant to simply throw out a piece of equipment that was expensive at the time of purchase just a few years earlier.

Donations are possible, but if a computer is too old for one user, it is most likely too old for the average user. With new computers comes new software, and up-to-date equipment is necessary to run it and to surf the Internet.

But that does not mean all old computers are completely obsolete. It is a matter of functionality - what can you re-sell - said Patricia Dillon, a research associate at Tuft's University in Boston.

"From the various sources that I have spoken to, a Pentium 133 is the level of technology that is re-salable," Dillon said.

To resell a computer, "You need to get rid of the previous owners' footprints," she said.

The current data needs to be destroyed and an operating system needs to be reloaded, she said. If a computer is donated, the recycling company is not licensed to use the software and must buy new software or the computer cannot be re-sold.

Older models, like the 386 or 486, can't run up-to-date software, but they are still useful.

"You can't really do what the average user wants to do on it," Dillon said, but special needs organizations can even use old models to teach typing.

Ohio University uses older models for lower-level computer tasks. The Computer Science department is getting rid of about six 386-model computers, said John Tysko, the systems administrator for the Computer Science department.

All computers OU trashes are state property, so the only option for disposal is to sell them at OU's periodic auctions of school property.

Tysko expects to upgrade the residence hall computers every two to three years. The used PCs will be available to upperclass students and any that remain will be auctioned off, he said.

Both the computers that have made it to the landfill and those that are on the way pose a problem bigger than the space they will fill.

About half of the 700 chemicals used to manufacture computers are toxic. Those that do not leak into the soil might be released into the air through incineration.

Tim Landers, District Manager of Waste Management, which services South Central Ohio, said all of Southern Ohio uses landfill disposal instead of incineration, so his company has no policy prohibiting the pickup of personal computers from individual residences.

But Waste Management does encourage those who call with questions about throwing computers away to donate them to local schools or Goodwill.