A press conference for what is considered the first computer, the Electronic Numerical Integrator and Calculator (ENIAC), was held at the University of Pennsylvania on February 1, 1946. The machine (shown here with a technician) took up an entire room, weighed 30 tons and used more than 18,000 vacuum tubes to perform functions such as counting to 5,000 in one second. ENIAC, costing $450,000, was designed by the U.S. Army during World War II to make artillery calculations. The development of ENIAC paved the way for modern computer technology--but even today's average calculator possesses more computing power than ENIAC did.