In the US, John Vincent Atanasoff and Clifford E. Berry of Iowa State University developed and tested the Atanasoff–Berry Computer (ABC) in 1942, the first "automatic electronic digital computer".
Inženir Tommy Flowers, ki je v 1930ih delal pri poštnem raziskovalnem uradu (Post Office Research Station) v Londonu, je pričel raziskovati možne načine uporabe elektronike v telefonskem prometu.