Artifacts from the first 2000 years of computing.

In some ways, collecting old computers isn't much different from collecting anything old: You have to take care of the stuff. "Is it decaying?" asks Dag Spicer, senior curator at the Computer History Museum, in Mountain View, Calif. He describes the remains of sound- dampening foam that once hushed the whir of cooling fans in 1960s and '70s mainframes. "It turns into a tarry mess- really gross, black sludge," he says. That's relatively easy to clean out, but some troubles require more technical expertise. Reading the information on a 1950s disk stack might be hard, says Spicer, a circuit designer turned historian, but harder still is making sense of it. "Do you recognize what these bits are?" he asks, explaining the need for both obsolete hardware and outdated operating systems. [ABSTRACT FROM PUBLISHER]