In the spring of 2000, as the tremors of the Nasdaq stock-market quake reverberated out of Silicon Valley, a new computer-related phenomenon was making quiet rumblings on the east coast of America. A small country saleroom a few miles from Boston was hosting an auction of early technology, billed as the first of its kind. Up for grabs were pieces of hardware which had turned from attic junk into museum collectables.
Many of the hundred or so bidders who turned out that crisp morning were after automata, the sometimes creepy home entertainments of the Victorian age: a parade of dancing animals and fairground mechanicals. But then came what for a small knot of people in the auction room was the main event.
Many of the lots appeared to be simple lab stuff: a slide rule, a tool kit, manuals and ephemera. But the plum of the collection was a piece of the Eniac - the Electronic Numerical Integrator and Computer generator made by J Presper Eckert and his colleague, John Mauchly, at the University of Pennsylvania in the 1940s. All of the items had belonged to Eckert himself. His widow had found them in the attic and auctioneer George Glastris sensed that there might be a market.
The slide rule fetched $3,000 (£1,900). A bundle of books relating to another precursor of the modern computer, the Univac, went for $2,000. Eventually, the Eniac ring counter - a section of glass valves about three feet long - was presented to the hushed saleroom. The hammer went down at $70,000 (£44,500) and Glastris was delighted.
The buyer of the ring-counter was not present but turned out to be Microsoft's founding technologist, Nathan Myhrvold. His collection of early technology, built up from internet auction purchases and personal contacts, includes slide rules, text books, Cray supercomputers and Enigma coding machines (he has two), as well as personal pieces of Microsoft history. It is looked after by full-time curatorial staff. He has also funded two reconstructions of Babbage's Analytical Machine, the precursor of the Eniac. One of these finely wrought devices is for Myhrvold, the other is on display in the Science Museum in London, where the curator, Doran Swade, is one of the people who are pioneering ways to breathe life into early technology.
Another is Dag Spicer, curator of the Computer History Museum in Silicon Valley. Snapped up from Stanford University by the museum's co-founders, Gordon and Gwen Bell, in 1997, Spicer is the museum's longest-serving employee. He has seen it grow from modest beginnings at the Moffett Field airbase, into its present multi-million dollar headquarters in Silicon Valley, in a building vacated by a former dot.com giant.
The collections held by Myhrvold and curated by Spicer and Swade are at one end of the scale of an appreciation of early technology; at the other are the small-time enthusiasts who scour charity shops for elusive machines and parts. There is money in old tech. In 2000, an Apple 1 was sold for $25,000 to a Japanese collector. But the enthusiasts I have trailed over the past three years have been motivated more by a desire to preserve old technology for future generations than to make a big profit. Most of them are techies, who use their expertise to bring old machines whirring back into life.
While a few academic institutions are consolidating this emerging field of research - Stanford University has the Apple archive, and the Lower Hudson River Information Centre in New York state uses its collection as a classroom aid - corporations have also woken up to the value of their heritage. Hewlett-Packard paid more than $1m for the residential garage, with house attached, where Hewlett and Packard started out.
Collectors around the world communicate and trade via the internet - there are several classic-computer sites - but they also meet up in Silicon Valley, Boston and Munich at vintage computer festivals devised by collector Sellam Ismail. At 14, Ismail sold his first computer - an Aquarius made by Mattel, maker of the Barbie doll - to a nine-year-old, and has regretted it ever since: "I realise now that it was as much a part of my personal history as my photographs and other memorabilia. It helped lay the foundation of my life in computers."
Since then he has spent every spare moment hauling hardware, manuals and ephemera between his home in Livermore, California, and various storage units. Now 31, he has amassed a vast collection of material that would otherwise have been land-fill, and intends to use some of his 1,300-plus computers to teach children about early technology. Ismail set up vintagetech.com to help fund his collecting. He also hires out machines for film and advertising, and to lawyers working on prior patent suits.
Collectors are not confined to America - John Honniball, a Briton, has more than 100 machines. He started computing at school and was featured in the Guardian in 1979 with his Commodore PET 2001 (8k memory, 6502 processor at 1MHz). "That computer would now be a classic." He keeps his collection at home, near Bristol: "I must consider a storage unit somewhere," he says.
The enthusiasms of collectors shed new light on computer technology and how we have grown used to it. It places the early computer pioneers in a timeline which most people who have ever used a computer can understand and applaud. In the three years I have been writing about computer collectors, I have developed a real fondness for their enterprise. They store their collections in garages, basements, outbuildings and, in the case of Marvin Johnston in Santa Barbara, in their cars. The word passion, not normally associated with computers, is at the heart of their unrelenting quests for a particular model or manual. These really are personal computers.
· Christine Finn is a research associate at the Institute of Archaeology, Oxford. She is the author of Artifacts: An Archaeologist's Year in Silicon Valley (MIT Press).
