Computer history is carefully stored at a US university.

I am writing this in the reading room of the Charles Babbage Institute at the University of Minnesota, perched above the Mississippi River in the suburbs of Minneapolis. The institute, founded in 1977, is one of the few organisations in the world devoted to the history of the computer industry and information technology.

Over the past 25 years the institute has collected an archive of more than 600 cubic metres of documents on the history of computing. I have come to Minneapolis to visit this fine collection. It contains the private papers of many of the pioneers of the computer industry and a lot of internal company records. These include the entire corporate archives of Burroughs, one of the two companies that merged to form Unisys in 1987.

There are hundreds of thousands of brochures, reports, market research analyses and other documents either not available elsewhere or scattered piecemeal. It is a treasure-house of IT history unrivalled in the world.

The institute's director is Arthur Norberg, one of the best-known and most respected historians of science and technology. He was the institute's first full-time director, from 1981 to 1993, and returned to the post in 1999. He is also a professor at the university, where he holds the chair in the history of technology.

"The institute is much more than just a library," Norberg explains."We are also involved in teaching people about the history of computing, and in training them to do research in the subject. We have had many graduate and post-doctoral students at the facility. We also use our research project to help uncover more archival material. We often don't know what's out there until one of our researchers starts digging. They will come across references to companies that we didn't even know existed."

The institute collects much more than documents. It has a collection of more than 150,000 pictures, brochures, films and other illustrative material. It also maintains an extensive oral history program that aims to capture some of the reasons computer companies made the decisions they did.

"We can tell what companies did from the published record," says Norberg,"but we often can't tell why or how. By interviewing some of the people involved in those decisions, we can grasp how the decision-making process worked."

The professor is very proud of the institute's collection and how it has grown over the years. It is open to the public but is not a lending library. The collection is housed in the Elmer L. Andersen Library, a purpose-built archiving establishment with more than 8000 square metres of storage in caverns drilled out of sandstone. Built five years ago and named after a state governor, the library houses several other special collections.

These include the Children's Literature Research Institute, which is one of the world's most extensive collections of children's books and information about their authors; the Immigration History Research Institute; the Social Welfare History archives; and the Givens Collection of African-American history. It also houses one of the world's largest collections of Sherlock Holmes material.

Professor Norberg took me into the storage area, 20 metres below ground, where the temperature and humidity are kept at the optimum levels for document storage.

Henry Ford said"History is bunk". History is not bunk. We can understand computing technology, and where it will take us, if we understand where it has come from....