E.S.R. Inc.

E.S.R., Inc. was an American manufacturer of educational toys during the 1960s. The company’s founders included William H. Duerig and Irving J. Lieberman, both involved in missile research at Kearfott Guidance in New Jersey, and C. David Hogan, an engineering student at Stevens Institute of Technology (who happened to be renting a room from Duerig and his wife). Together the three brainstormed Lieberman’s concept for a simple mechanical computer, and showed a prototype at the annual Toy Fair in New York City. With encouragement from toy buyers, the three engineers established E.S.R., Inc. in 1963 to produce and market their new toy, dubbed the Digi-Comp I. According to Duerig, the initials "E.S.R." didn’t actually stand for anything....