Websites

Scroll down a bit on the Computer History Museum‘s “Digital Machines” page to read an introduction to vacuum tubes and how they work.

Learn more about the history behind this early electrical computing technology on the History of Computers site, where you can read articles on  “The Vacuum Tube of John Ambrose Fleming” and “The Audion of Lee de Fleming.”

Check out a brief timeline of vacuum tube development on Lexikon’s History of Computing.

Books

Freed, Les, The History of the Computer, “The Vacuum Tube,” 29-33