ENIAC Computer
ENIAC, short for Electronic Numerical Integrator And Computer,was an early electronic, digital, general purpose, programmable computer. It was the first Turing-complete, digital computer capable of being reprogrammed to resolve a broad range of computing problems, although earlier machines had been built with only some of these attributes.
The first of the four computers that Eckert built with Mauchly was the ENIAC (Electronic Numerical Integrator and Computer). ENIAC wasn't the first computer in world history. It did, all the same, dramatically improve computing technology. Archaic by contemporary computing standards, for the time period, ENIAC was a marvelous machine.
ENIAC was a product of World War II. The military required the development of firing tables for its artillery, so that gunners in the battlefield could rapidly calculate up which settings to use with a specific weapon on a particular target under specific conditions. The equations to determine these numbers were so complicated, they took days for a human to calculate; existing mechanical calculators could perform only slightly better. The Ballistics Research Laboratory (BRL), responsible for supplying these figures to soldiers in the field was lagging behind, but soon heard about the work of John Mauchly at the Moore School. In 1942, he had suggested employing vacuum tubes to speed up computer calculations.
Lieutenant Herman Goldstine of the BRL pursued this. Before long BRL authorized work on a new high-speed computer with Mauchly as chief advisor, his colleague J. Presper Eckert as chief engineer, and Goldstine as liaison. This was in 1943. It required about a year to design ENIAC, and 18 months to construct it. ENIAC weighed over thirty tons and was made up of 17,468 vacuum tubes, seventy thousand resistors, five million soldered joints, ten thousand capacitors, six thousand manual switches, and 1,500 electrical relays. The computer covered 1,800 square feet of floor space. Separate wire panels defined each of its programs, which signified that operators had to switch its wiring manually by twisting dials, shifting switches, and running cables every time they converted to a new program. Contributing to its complexity were almost 18,000 vacuum tubes, any one of which could burn off at any time and stop a calculation.
By the time it was completed, in November 1945, the war had been finished for three months. The project was two hundred percent over budget (total cost approximately $500,000). But it had accomplished what it set out to do. A calulation like determining the cube root of 2589 to the 16th power could be made in a fraction of a second. In a single second, it could execute five thousand additions, thirty-eight divisions, or three hundred multiplications. It was one thousand times quicker than calculators of this period of time. ENIAC could calculate a trajectory for an artillery shell in 30 seconds, while it required a human using a mechanical desk calculator 20 hours to execute the same calculation, with the possibility of error.
The ENIAC was a general-purpose computer that could add, subtract, multiply, divide, compare amounts, and express square roots. It didn't go into operation until after World War II. The ENIAC cleared its first full functional test on December 10, 1945 and in August 1947, it was employed to solve trajectory problems and calculate ballistics tables at the U.S. Army's Aberdeen Proving Ground, and was subsequently employed in the development of the hydrogen bomb.
At the heart of ENIAC was a device known as a ring counter, which consisted of 10 vacuum tubes in a circle. A "5" would be presented by a pulse at the fifth tube. If a person added 9 to that, the pulse would shift to the fourth tube, while the first tube on a second ring--representing the 10--would receive a pulse. Ten ring counters were located in each accumulator, which could store numbers running up to 10 billion minus one (9,999,999,999) or down to negative 10 billion plus one. When an individual accumulator hit its upper limit, a pulse could be directed via wire to a second one, carrying on the process altogether, ENIAC held 20 accumulators dispersed over 40 racks networked together by plug boards. Data was stored in pulses in 5-foot mercury tubes.
ENIAC's principal drawback was that programming it was very difficult. In that sense it wasn't a general use computer. To modify its program entailed essentially rewiring it, with punchcards and switches in wiring plugboards. It could require a team two days to reprogram the machine. In spite of its faults, the lessons learned from ENIAC helped computer developers improve the next generation, including EDVAC, UNIVAC, and Whirlwind, all of which bettered programmability and memory storage. One of ENIAC's greatest deeds was in demonstrating the potential of what could be done.
Besides covering the history of the computer, our site also has articles on improving your Internet connection, reviews of Internet Providers, and a technology blog which details advances in the areas of computers & the Internet.