A computer that used vacuum tubes as switching elements; for example, the UNIVAC I. See computer generations. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

Along with subsequent computers that also used vacuum tubes, ENIAC was known as a first-generation computer. ENIAC could execute up to 5,000 additions per second, multiple orders of magnitude ...

the first programmable electronic computer. Various university campuses in Britain and the US were home to first-generation computers like ENIAC, EDVAC and the Manchester Baby in the late 1940s.