was controlled from prepunched paper tape. Output was by card punch and electric typewriter. It was slow, requiring 3 to 5 seconds for a multiplication, but it was fully automatic and could complete long computations without human intervention (Chposky, 103). The outbreak of World War II produced a desperate need for computing capability, especially for the military. New weapons systems were produced which needed trajectory tables and other essential data. In 1942, John P. Eckert, John W. Mauchley, and their associates at the University of Pennsylvania decided to build a high-speed electronic computer to do the job. This machine became known as ENIAC, for "Electrical Numerical Integrator And Calculator". It could multiply two numbers at the rate of 300 products per second, by finding the value of each product from a multiplication table stored in its memory. ENIAC was thus about 1,000 times faster than the previous generation of computers (Dolotta, 47). ENIAC used 18,000 standard vacuum tubes, occupied 1800 square feet of floor space, and used about 180,000 watts of electricity. It used punched-card input and output. The ENIAC was very difficult to program because one had to essentially re-wire it to perform whatever task he wanted the computer to do. It was, however, efficient in handling the particular program...
