ENIAC

Details of the rear section of a part of the ENIAC, showing thermoonic valves on.

ENIAC, an acronym for Electronic Numerical Integrator And Computer (Computer and Numerical Electronic Integrator), was one of the first general-purpose computers. It was Turing-complete, digital, and capable of being reprogrammed to solve "a broad class of numerical problems". It was initially designed to calculate artillery firing tables for the United States Army Ballistic Research Laboratory.

Engineers John Presper Eckert and John William Mauchly led the development, with Eckert designing the hardware and Mauchly designing the concept.

Six women were also in charge of programming the computer: Betty Snyder Holberton, Jean Jennings Bartik, Kathleen McNulty Mauchly Antonelli, Marlyn Wescoff Meltzer, Ruth Lichterman Teitelbaum and Frances Bilas Spence.

Modalities

It has generally been regarded as the first general-purpose computer, although this title actually belongs to the German Z1 computer. It is also related to the Colossus, which was used to break German code during World War II and destroyed after use to avoid leaving evidence, being restored for a British museum. It was totally digital, that is to say, it executed its processes and operations through instructions in machine language, unlike other contemporary computing machines with analog processes. Its first commissioning was on December 10, 1945 and it was presented to the public on February 14, 1946.

ENIAC was built at the University of Pennsylvania by John Presper Eckert and John William Mauchly, it occupied an area of 167 m² and operated with a total of 17,468 electronic valves or vacuum tubes that in turn allowed nearly 5,000 addition and 300 multiplications per second. Physically, the ENIAC had 17,468 vacuum tubes, 7,200 glass diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors, and 5 million solder points. It weighed 27 tons, measured 2.4 m x 0.9 m x 30 m; used 1,500 electromagnetic switches and relays; it required the manual operation of some 6,000 switches, and its program or software, when it required modifications, took weeks of manual installation.

The ENIAC raised the temperature of the premises to 50 °C. To carry out the different operations, at first it was necessary to change, connect and reconnect the cables as was done, at that time, in telephone exchanges, hence the concept. This work could take several days depending on the calculation to be carried out, although allowing the different elements to operate in parallel made the machine extremely fast. Later, however, it was modified into a stored-program machine, using the constant tables (the big rolling cabinets full of switches) to store the code. Although this made the speed of the machine less, having to perform all its operations in a purely sequential manner, it greatly simplified the programming work.

One of the myths surrounding this device is that the city of Philadelphia, where it was installed, suffered from blackouts when the ENIAC came into operation, since its consumption was 160 kW.

At 23:45 on October 2, 1955 the ENIAC was deactivated forever.

ENIAC's design and construction was funded by the US Army, Ordnance Corps, Research and Development Command, led by Major General Gladeon M. Barnes. The total cost was about $487,000. The construction contract was signed on June 5, 1943; work on the computer began secretly at the University of Pennsylvania's Moore School of Electrical Engineering the following month, under the code name "Project PX", with John Grist Brainerd as principal investigator. Herman H. Goldstine persuaded the Army to fund the project, which put him in charge to oversee it on his behalf.

Reliability

ENIAC used octal-based thermionic valves, common at the time; decimal accumulators were made with 6SN7 valves, while 6L7, 6SJ7, 6SA7, and 6AC7 valves were used for logic functions. Numerous 6L6 and 6V6 tubes were used as pulse guides between the cables connecting each ENIAC rack.

Some electronics experts predicted that the valves would fail so often that the machine would never be useful. This prediction turned out to be partially correct: several valves melted almost every day, rendering ENIAC inoperative. Tubes specially made to last long periods of time without deteriorating were not available until 1948. Most of these failures occurred during ENIAC startup or shutdown, when the tube filaments and their cathodes were under thermal stress. By taking the simple and expensive action of never shutting down the ENIAC, engineers reduced valve failures to the acceptable figure of one valve every two days. According to a 1989 interview with Eckert, continuous valve failure is a myth: "We would have a valve fail about every other day and we could figure out the problem in less than 15 minutes." In 1954 the ENIAC operated without failure for 116 hours (about five days).

Features

Calculate the trajectory of projectiles and perform mathematical operations.

• In 1.5 seconds he was able to calculate the power 660000 of a number of 10 figures.

• ENIAC could solve 5000 sums or 300 multiplications in 1 second.

ENIAC programmers

Although it was the ENIAC engineers, Mauchly and Eckert, who went down in history, there were six women who were in charge of programming the ENIAC, whose history has been silenced over the years and recovered in the last decades Classified at the time as "sub-professionals", possibly for reasons of gender or to reduce labor costs, this team of programmers noted for their mathematical and logical skills and worked by inventing programming as they went.

In 1943, during the course of World War II, calculators and direct supervisors were primarily women. This is because, on the one hand, the Second World War was a key moment in history in terms of women's employment, since men were recruited in combat and it was women who replaced them in the workplace.. An example of this are the new American civil and military organizations such as the WAAC (Women's Auxiliary Army, of the army), WAVES (Women Accepted for Volunteer Emergency Service, of the Navy) and the AWVS (the American Women's Voluntary Services) that directed women towards various jobs. The press emphasized the importance of machines in warfare and called on women with mechanical knowledge to serve industry and government under the slogan "women wanted."

On the other hand, women dedicated to what today is considered programming, unlike the male sector, did not aspire to a professional job at higher levels but settled for positions of little renown in the world of computing where you can make use of your capabilities. According to Herman Goldstine (the main developer of the ENIAC) stated in an interview on November 16, 1994, that it was the fact that women did not aspire to higher positions that made them the ideal worker. The men who worked in programming did not see it as a goal but as a temporary job to earn a quick income. Programmers aspired to higher value employment and were dedicated to competing with each other, so they did not put as much effort and dedication into their work as women for whom programming was their only job opportunity. Consequently, women were more meticulous and quicker than men in this job and received a more modest salary, so their hiring entailed numerous advantages.

ENIAC's group of programmers consisted of: Betty Snyder Holberton, Jean Jennings Bartik, Kathleen McNulty Mauchly Antonelli, Marlyn Wescoff Meltzer, Ruth Lichterman Teitelbaum and Frances Bilas Spence, who hardly appear in computing history books, although they spent long hours working with the machine, used mainly for ballistic trajectory calculations and differential equations, contributing to the development of computer programming.

When the ENIAC later became a legendary machine, its engineers became famous, while no credit was ever given to these six women who did the programming.

Even though women began to fill jobs related to engineering and science in World War II, gender discrimination at work was still present. Recognition fell solely on male leaders, and publicity photographs rarely showed women's contributions.

Many photo records from the time show ENIAC with women standing in front of it. Until the 1980s, they were even said to be just models posing next to the machine (“Refrigerator ladies”). Yet these women laid the foundation for making programming easy and accessible to all, creating the first set of routines, the first software applications, and the first classes in programming. Their work dramatically changed the evolution of programming among women. decades of the 40s and 50s.