Valuable blasts from the past: The 7 items most prized by computer collectors

There are some things money can buy, some that it can't -- and some that are a joy at a good price.

Credit: Bob Roswell

Bob Roswell, co-owner of System Source, has been showcasing his computer collection ever since his company moved into a former Gucci store in downtown Baltimore in the '80s and he needed something to do with the former display room. System Source is now headquartered in the suburbs south of the city, but Roswell still owns and showcases a collection of fun old electronic equipment (assuming you find old electronic equipment fun, which I definitely do). I asked him about some of the great treasures sought out by computer collectors -- some for profit, some for glory, and some just for personal affection.

Apple I

The Apple I, the computer that Steve Wozniak famously designed and Steve Jobs hawked to the burgeoning computer market in 1976, is the sort of piece of computer history that, as Roswell puts it, all you need in order to own it is money. You need quite a lot of money, of course -- one sold just this month for $330,000. -- but hundreds were sold originally, many still exist, and they tend to surface at auction fairly regularly. If you really want one, all you have to do is wait (and have a six-figure sum to spend on a computer from the '70s, of course).

Univac 490

Then there are those pieces that you can only get under very specific and unique circumstances. The 14-foot long UNIVAC 490 that is the pride of Roswell's collection definitely falls into this category; only 47 were made, including two that served as the first primitive airline reservation systems, and their sheer size mitigated against most people just holding onto them for fun after they were no longer useful. The machine Roswell has at System Source was found in the home of someone who seemed to hoard electronics. Getting the 490 actually up and running is a task Roswell has set for his retirement.

Drum memory

Roswell holds out hope that other treasures might emerge from some forgotten storage locker or warehouse, but doesn't expect that to happen anytime soon. He says he'd be "absolutely thrilled" to find some drum memory from the same period as his UNIVAC. The Computer History Museum in Mountain View, California, has an impressive-looking if damaged drum memory unit in its collection, as you can see in this video.

Antikythera mechanism

Then there are those finds that are completely unique, that there's no real hope of any ever coming on the market. Roswell cites the Antikythera mechanism as the ultimate example of this. The rusting remains of this device, believed to have been used to model astronomical phenomena, were fished out of a 1st century Greek shipwreck in 1900. The mechanism, deemed the earliest known analog computing device, probably wasn't one of a kind in its day, but the chances of another one showing up are astronomically small.

Pascal's calculator

Earlier this year there was flurry of interest that just such an impossibly rare bird had emerged from hiding. The auction house Breker claimed to be offering a pascaline, a 17th century mechanical calculator invented by Blaise Pascal. Only 10 were known to exist, and so the emergence of an 11th would've been a sensation. However, tech history enthusiasts were rather quickly able to tell from photos alone that it was a replica.

Your first computer

For many collectors, their most prized possession isn't the rarest of the rare, though. It's the first or second computer they worked on. That's why many tech collectors are so pleased to find computers like the Commodore 64 or Timex Sinclair 1000 (pictured). While these computers weren't manufactured in the huge numbers that modern day PCs and phones are, their production runs were in the hundreds of thousands or millions, and they're relatively easy to lay your hands on -- all the better for bringing joy to the computer nostalgist. (For me, my brief passion was classic Mac hardware, which eBay easily indulged.)

Digi-Comp I

Roswell's own easy-to-find retro computer passion? The Digi-Comp I, a programmable mechanical computer made entirely out of metal and plastic. Manufactured from 1963 to 1967, the Digi-Comp has inspired enough passion to support a Yahoo group with almost 1,000 members. Presumably those people paid more than the Digi-Comp's original $4.99 -- though not, presumably, that much more.