They're big, dusty and frequently haven't run in decades, but some old computers still fetch astronomical prices. Systems dating back to the 1960s can change hands for $20,000 or more. What's the big deal about hardware from bygone eras?

The accidental collector

"I began to see some really nice minicomputers go off to landfills and for scrap, and thought it was a shame to see such historically important machines just get junked," says Carl Friend of the retro-computing society, based in Providence, Rhode Island. "It made sense to me to try and save a few. It wasn't a desire to have a collection until I already had one."

Friend rescues vintage minicomputers, specifically those made by Data General and the Digital Equipment Corporation (DEC). Companies like these were once household names in the 1960s. Ranging from the size of a washing machine to a large wardrobe, the minicomputers they produced were frequently the only number crunchers available to smaller businesses and university departments. They ushered in the era of affordable computing and formed a distinct class of machine for nearly two decades.

Friends have problem

Given their large size and the number of machines he owns (13 Data Generals, 7 DECs, plus a range of smaller workstations), Friend has space problems. He admits: "That's a chronic bone of contention between my wife and I!"

"Some of my minis, and until recently all of my workstations, lived in our rather small house. This, as you might imagine, put some severe strains on open space in the house and also on our relationship. Since I'm one of the members of the board of directors of the Retro-Computing Society, we had available space there for me to store some of my larger machines and, now, many examples of the workstation class."

Spousal influence is a common compromising factor for those involved in computer conservation, but in one collector's case, it actually sparked him to begin collecting.

Spousal approval required

"I work out of a home office, and I tend to work odd hours," says Dave Dunfield, a Canadian computer consultant and software developer. "One year at the Christmas holidays my wife decreed that I would not enter the office during vacation time."

While mooching about in his basement looking for something to do, Dunfield decided to unpack and set up his old MITS Altair 8800. "I have what I believe is one of the first Altair computers to come into Canada," he says.

The Altair was the machine that sparked the home computer revolution in 1975. It came as a mail order kit sold through hobbyist magazines Popular Electronics and Radio Electronics. The Altair also convinced Bill Gates to found Microsoft and market a BASIC interpreter for it.

Altair worship

"With a bit of restoration I had it up and running. As I immersed myself in memories of my early career it occurred to me that these experiences were lost to modern generations and I decided to do what I could to preserve them," recalls Dunfield. "I began by writing a software simulation of my Altair and archiving all of my diskettes as data files that could be used with the simulator. Then I put up a web page with the simulator and a 'photo gallery' of the system itself. Originally it was a single page featuring only my Altair, however it has grown considerably since then."

His extensive collection catalogue site meticulously details the rarity and state of everything he owns, from programmable calculators to his prized Altair. How many of them still work?

"I maintain most of the systems in operating condition," says Dunfield. "I try to check each system at least once a year and perform repairs as required."