Computer History Museum has one of the world's largest collection of computing artifacts. Basically they have a huge collection of computer stuff all the way from the beginning. Quite impressive actually. Visitors can see for themselves those old massive computers of yester-years for themselves. The purpose is for visitors to experience computer revolution and understand its impact on us on the whole. They have several interesting exhibits like "Visible Storage", "Innovation In The Valley" and "Mastering The Game". All the tours are free. Please check out their website on the operating hours.