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Private company

E.S.R., Inc.

Educational toy manufacturer based in U.S.

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.2 Wikipedia text CC BY-SA 4.0

Last updated Oct 21, 2026.

Overview

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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.2

Products and brands

  • Digi-Comp I

Listed on Wikidata.1

Sources

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