er to do the job. This machine became known as ENIAC, for Electronic Numerical Integrator and Computer (or Calculator). The size of its numerical word was 10 decimal digits, and it could multiply two such numbers at the rate of 300 products per second, by finding the value of each product from a multiplication table stored in its memory. Although difficult to operate, ENIAC was still many times faster than the previous generation of relay computers.ENIAC used 18,000 standard vacuum tubes, occupied 167.3 m6 (1,800 ft6) of floor space and consumed about 180,000 watts of electrical power. It had punched-card input and output and arithmetically had 1 multiplier, 1 divider square rooter, and 20 adders employing decimal "ring counters," which served as adders and also as quick-access (0.0002 seconds) read-write register storage. The executable instructions composing a program were embodied in the separate units of ENIAC, which were plugged together to form a route through the machine for the flow of computations. These connections had to be redone for each different problem, together with presetting function tables and switches. This "wire-your-own" instruction technique was inconvenient, and only with some license could ENIAC be considered programmable; it was, however, efficient in handling the particular programs for which it had been designed. ENIAC is generally acknowledged to be the first successful high-speed electronic digital computer (EDC) and was productively used from 1946 to 1955. A controversy developed in 1971, however, over the patent ability of ENIAC's basic digital concepts, the claim being made that another U.S. physicist, John V. Atanasoff, had already used the same ideas in a simpler vacuum-tube device he built in the 1930s at Iowa State College. In 1973 the court found in favor of the company using the Atanasoff claim. The Modern "Stored Program" EDCIntrigued by the success of ENIAC, the mathematician John von Neumann ...
