in full Electronic Numerical Integrator and Computer.
Early electronic digital computer built in the U.S. in 1945 by John W. Mauchly .
The massive ENIAC, which weighed 30 tons and filled an entire room, used some 18,000 vacuum tubes , 70,000 resistors, and 10,000 capacitors. In December 1945 it solved its first problem, calculations for the {{link=hydrogen bomb">hydrogen bomb . After its official unveiling in 1946, it was used to prepare artillery-shell trajectory tables and perform other military and scientific calculations.