Roswell usually waits years to add newer devices, partly because he wants to gauge their historical impact on the computing industry and also because he can find them cheap or for free on eBay.com or other sources. For these reasons, he said, there won’t be an Apple iPad on display anytime soon.

There are only a handful of official museums in the United States dedicated to computers. The Smithsonian’s National Museum of American History has a computer exhibit in Washington.
On the West Coast, the world’s largest collection of computer artifacts resides in Silicon Valley, at the Computer History Museum.

Little lamented that academic institutions seem less interested in maintaining exhibits on computing history, leaving it to private industry to set up or pay for their own.

Computer companies and hobbyists, such as Roswell, often fill a void in their communities by setting up their own exhibits, according to Alex Bochannek, a curator at the Computer History Museum in Silicon Valley in California.

Bochanek said people get nostalgic about the first computer they used, and can relate to the gadgets on exhibit on a personal level. But historical computer exhibits can also educate people, he said.

“They used to be seen as menacing, but a lot of people now couldn't imagine their daily lives without computers,” Bochanek said. “To a lot of people, it's just a big metal box. But you have to explain to people what the applications were, what people could do [with a computer] when before they could not.”

Among the items on display at Roswell’s museum are a comptometer, a 19th-century addition and subtraction machine; a 1960s-era DigiComp 1, a plastic computer that could do simple math and play some logic games; and an Altair 8800, a build-it-yourself kit from the mid-1970s that became the first popular personal computer.

On one wall, he also has a selection of IBM, Commodore, Atari and Radio Shack computers. Another display features many Apple and Mac computers. Still another display features portable devices, such as the Palm Pilot, a kind of personal digital assistant and the precursor to the smart phone.

Roswell’s exhibit drives home a key point about modern computing: Both speed and storage space have grown exponentially as prices have dropped dramatically. The advances have been so steep that a modern cell phone would outperform any of the computers that Roswell has on display, he said.

The next exhibit that Roswell wants to assemble would demonstrate Maryland’s contributions to computing. Aberdeen Proving Ground in Harford County, the National Security Agency at Fort Meade, and the Social Security Administration in the Baltimore area are all government agencies that incorporated powerful computers in their work.

“Maryland’s got a lot to be proud of,” said Little.