The Birth

of a

New Age

by

Charles Morgan

Often referred to as a dinasaur, a behemoth, or a monster, mainly because of its enormous size, it was instrumental in paving the way to the new age of computers. This giant that I refer to was unveiled on Feb 15, 1946 at the Moore School for Electrical Engineering of the University of Pennsylvania and was called ENIAC (Electronic Numerical Integrator and Computer).

ENIAC was designed at the request of the military in preparation of possibly becoming involved in World War 2 which was already in progress. The military had designed new weapons and were conducting testings at Aberdeen Proving Ground in Maryland. In order for these large guns to accurately hit their designated target, trajectory tables had to be produced. Many factors had to be calculated such as: gun angle, wind speed and direction, temperature, atmospheric pressures and humidity. These calculations were done by people who did it all by hand and this process took hours for just one trajectory. A faster and more reliable way had to be found.

A Bush Differential Analyzer, invented in 1925 by Dr. Vannevar Bush, was installed at the Ballistic Research Labratory (BRL) to help speed up the calculations but because this device was made up of rotating shafts, wheels and powered by electric motors many drawbacks came with it. One being that an important part of the differential analyzer called a torque amplifier, which improved the speed, frequently failed near the end of the calculations which resulted in costly downtime while repairs were being made. Once again the need for someting faster and more reliable was in dire need.

Lieutenant P. N Gillon of the Ordnance Department knew that the Moore School of Electrical Engineering had their own Bush Differential Analyzer and it was larger and faster than the one at the BRL. Meetings between the two were arranged and in June 1942 a contract was signed between the Ordnance Department and the Moore School which gave the Ordnance Department exclusive use of the differential analyzer to produce trajectory tables. This contract was headed by Dean Harold Pender and Professor J.G Brainard. Under them there was a large collection of talented scientists and engineers. Among them were two people who would become key players later on. They were John W. Mauchly , a Physicist and J. Presper Eckert , an Electrical Engineer. The team made improvements and modifications to the Bush Differential Analyzer and it did indeed perform faster and was less prone to failure but orders for new trajectory tables continued to arrive at an overwhelming rate and it still wasn't fast enough. Reliability had improved somewhat but speed now became of the utmost importance.

Earlier in 1941 Mauchly had made a trip to Iowa State University and visited Vincent Atanasoff. While there Atanasoff told him about his research into using electronics for numerical computation. Drawing from this experience Mauchly got together with Eckert and drafted the design of an automatic electronic computer suitable for solving the differential equations for the Ordnance Department. This proposal was presented to the military through the newly promoted Colonel Gillon and on June 5, 1943 the Ordnance Department signed a new contract with the Moore School to research, design and build an electronic numerical integrator and computer- ENIAC. This project was to be supervised by Brainard with Eckert as chief engineer and Mauchly as principal consultant.

Mauchly and Eckert started weeks before the official go ahead came down from the military in designing this computer and in the fall of 1945 construction was complete. ENIAC was indeed a grotesque monster when compared to the computers of today. It took up 1800 square feet and was 100 feet long and 10 feet high (arranged in a "U" shape). It weighed in at over 30 tons, consisted of over 18,000 vacuum tubes, 70,000 resistors, 10,000 capacitors, 6,000 switches, 1500 relays and consumed enough electrical power to light up a small town.

Programming ENIAC was no small task. Before ENIAC, people were referred to as "computers" and in the fall of 1945 six women computers were selected to program ENIAC . They were Jean Bartik, Betty Snyder, Marlyn Metzer, Ruth Teitelbaum, Frances Spence and Kay McNulty who later married Mauchly. Programming was done by wiring cable connections and setting three thousand switches. This had to be done for every problem and made using the machine very tedious but the speed of which the computations were done made up for this. Trajectory tables that had once taken someone with a hand held calculator twenty hours to do was reduced to fifteen minutes using the Bush Differential Analyzer and now using ENIAC it was done in a mere thirty seconds. The speed that the military so desperately wanted was now a reality. Reliability was there but it came with a few drawbacks. The use of vacuum tubes caused a few headaches due to their tendancy to burn out and on an average some fifty or so had to be replaced daily. A nuisance to maintain but acceptable. Another time consuming problem was when errors occurred. To find these errors one would literally have to go through the program one instruction at a time, checking each computation and comparing it to one carried out by hand. Once again tedious to do but acceptable.

Finally on February 15, 1946 ENIAC (Electronic Numerical Integrator and Computer) was dedicated by the University of Pennsylvannia. Its very first task was to solve atomic energy problems for the Manhattan Project. During the first year ENIAC was not limited to computing ballistic trajectories for the Ordnance Department but included weather prediction, atomic energy calculations, cosmic-ray studies, random-number studies and wind tunnel design. ENIAC was a success and in January of 1947 it was shipped to the Aberdeen Proving Ground and by August of that year it was put into operation for computation of trajectory tables.

ENIAC remained in operation until 11:45 PM August 2, 1955. At that time the Electronic Numerical Intergrator and Computer was shut down. Mainly because by then advances in computers made ENIAC obsolete. On February 15, 1996 celebrations were held to commemorate the 50th anniversary of ENIAC and to pay tribute to those who made ENIAC a reality. One of the highlights of this celebration was Eniac-On-A-Chip . A group of students attending the University of Pennsylvannia, under the supervision of Professor J. Van der Spiegel and Dr. F. Ketterer, got together and intergrated the whole ENIAC on a 7.44 by 5.29 sq. mm chip. This chip contains about 174,569 transistors.

ENIAC was indeed a marvel in its time and set the pace for the age that we now live. Today parts of ENIAC can be viewed on display in various museums throughout the world, including the Smithsonian in Washington D.C., and in the very same room that it was constructed at the Moore School for Electrical Engineering at the University of Pennsylvania. ENIAC may be " offline" as we say but we should remember that in every computer there is a little bit of ENIAC .