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.
"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."
Working into retirement
Finding replacement parts is becoming more of an effort as time goes by. "When I was first acquiring hardware," says Friend. "I was more interested in the processors than the peripherals. I now realise that was a mistake, as without the peripherals all one has is a heavy box with lights that blink. So of the minicomputers about six are in quickly runnable condition; I can mix-and-match some of the peripherals with other CPUs, but that takes time and a lot of effort."
One solution to the spares problem is online forums. Some sites, like The Vintage Computer, are extensive. There's technical support for maintaining, operating and programming old kit, as well as a thriving marketplace where members can buy, sell and exchange parts and even entire systems.
As well as being collectable, Dunfield's machines earn their keep. "I also use them frequently in data-recovery operations which I do on a contract basis," he says. This is an increasingly important reason for preserving old systems. Data storage formats quickly become obsolete, so collectors are frequently the only ones able to read archives from bygone decades. Much of NASA's data telemetry archive is lost unless someone can read its ancient IBM formats.
"Sometimes the collection gets used in a laboratory manner," adds Friend. "For instance, when the United States changed its Daylight Saving Time law in 2007, a large component of my workstation collection was used to develop and test patches to allow the production machines where I work to ride the change out without problems. I've also used the collection for teaching purposes by way of 'comparative anatomy' in helping people identify computer subsystems."
High tech antiques
With the success of sites like eBay, people have woken up to the idea that most modern cultural artefacts are collectable, and that goes for computers too. Prices are rising, but which systems are particularly worth keeping?
"That's a tough one," says Friend, "and 'most collectible' will vary from collector to collector. I know that PDP-8s are highly sought after, and command outrageous sums on places like eBay." He's right. Originally costing $18,000 in 1965, working PDP-8s now fetch between $2,000 and a cool $20,000.
Dunfield agrees: "Interest in classic computing varies all over the map, and a machine which is highly prized by one collector might not be considered worth carrying home by another," he warns.
If it's down to preference, which types of computer attract more collectors than others? "There are a large number of microcomputer collectors (non-PC micros, that is) around," says Friend, "and a few folks who collect mainframes, so it varies primarily on the tastes of the individual."
"My own main area of interest is microcomputers," adds Dunfield, "so to my mind the most collectable computers would be the ones based on the Intel 8008. These systems include the Mark-8, the Scelbi and the MIL MOD-8."
Also on Dunfield's list are the ultra-rare Kenbak (a pre-microprocessor kit dating back to 1971) and the iconic Apple-1, of which only a few hundred were ever made. It's this scarcity that drives prices up. "I have an Atari Transputer Workstation," says Dunfield. "Only 350 of these were made, and they are highly prized by some collectors."
Cash in the attic
So, when you next clear out the shed, garage, or attic, don't throw out those old computers until you've checked the prices they fetch on eBay. We found a Sinclair ZX80 in working order for £77, with eight bids against it and three days left to go – and on the US site was a working Commodore 64 home computer from 1982 with a Buy Now price of $700.