Photos: A trip down silicon memory lane

The DigiBarn is a computer history museum, nestled in a 90-year-old barn, deep in the Santa Cruz mountains about 90 minutes south of San Francisco.

The pride and joy of Nasa contractor Bruce Damer and his partner in curation, Alan Lundell, the DigiBarn might be described as a temporary museum in transition. That's because, on the one hand, it is always growing as the ageing lions of Silicon Valley donate their old playthings, and on the other, very wet winters force Damer and co to put everything in boxes every year to avoid losing it all to rust.

Yet, the collection is surprisingly broad, taking visitors from early 20th-century mechanical calculators all the way through modern web appliances, stopping along the way to focus on several important elements of the computer revolution. This image shows a giant disk used for storage on the Xerox Alto computer.