The Digi-Comp I was a $5 plastic computer powered by rubber bands

Sold in 1963, it ran on a hand-pulled clock lever and may have outnumbered real computers in the mid-1960s.

Digi-Comp I — A Digi-Comp I, showing the sliding display plates and the plastic program tubes. Photo by Pterre / CC BY-SA 3.0, via Wikimedia Commons

The Digi-Comp I was a plastic and rubber band toy that sold for $5 in 1963. According to Chris Staecker, a Fairfield University math professor who posted a video about its operation, "This was the first digi…