In pictures: Silicon Valley's birthplace

367 Addison Avenue is now California historical landmark No. 976

Visitors are kept away from the historic garage by an iron gate

Five years of work has restored the garage to its 1940s glory

Memorabilia on display shows Bill and Dave at work in the 1940s

Bill Hewlett lived in this humble garden shed for years

There were few home comforts inside the wooden shack

One of HP's first oscillators is on display in the living room