John Mauchly

John William Mauchly (August 30, 1907 – January 8, 1980) was an American physicist who, along with J. Presper Eckert, designed ENIAC, the first general-purpose electronic digital computer, as well as EDVAC, BINAC and UNIVAC I, the first commercial computer made in the United States.

Together, Mauchly and Eckert started the first computer company, the Eckert–Mauchly Computer Corporation (EMCC), and pioneered fundamental computer concepts, including the stored program, subroutines, and programming languages.

John W. Mauchly was born on August 30, 1907, to Sebastian and Rachel (Scheidemantel) Mauchly in Cincinnati, Ohio.

He moved with his parents and sister, Helen Elizabeth (Betty), at an early age to Chevy Chase, Maryland, when Sebastian Mauchly obtained a position at the Carnegie Institution of Washington as head of its Section of Terrestrial Electricity.

As a youth, Mauchly was interested in science, and in particular with electricity, and as a young teenager was known to fix neighbors' electric systems.

Mauchly attended E.V. Brown Elementary School in Chevy Chase and McKinley Technical High School in Washington, DC.

At McKinley, Mauchly was extremely active in the debate team, was a member of the national honor society, and became editor-in-chief of the school's newspaper, Tech Life.

There he met the lab instructor, J. Presper Eckert (1919–1995), with whom he would form a long-standing working partnership.

After graduating from high school in 1925, he earned a scholarship to study engineering at Johns Hopkins University.

His first wife, Mary Augusta Walzl, a mathematician, whom he married on December 30, 1930, drowned in 1946.

John and Mary Mauchly had two children, James (Jimmy) and Sidney.

He subsequently transferred to the physics department, and without completing his undergraduate degree, instead earned a Ph.D. in physics in 1932.

From 1932 to 1933, Mauchly served as a research assistant at Johns Hopkins University where he concentrated on calculating energy levels of the formaldehyde spectrum.

Mauchly's teaching career truly began in 1933 at Ursinus College where he was appointed head of the physics department, where he was, in fact, the only staff member.

In the summer of 1941, Mauchly took a Defense Training Course for Electronics at the University of Pennsylvania Moore School of Electrical Engineering.

In 1941 Mauchly took a course in wartime electronics at the Moore School of Electrical Engineering, part of the University of Pennsylvania.

There he met J. Presper Eckert, a recent Moore School graduate.

Mauchly accepted a teaching position at the Moore School, which was a center for wartime computing.

Eckert encouraged Mauchly to believe that vacuum tubes could be made reliable with proper engineering practices.

The critical problem that was consuming the Moore School was ballistics: the calculation of firing tables for the large number of new guns that the U.S. Army was developing for the war effort.

In 1942 Mauchly wrote a memo proposing the building of a general-purpose electronic computer.

The proposal, which circulated within the Moore School (but the significance of which was not immediately recognized), emphasized the enormous speed advantage that could be gained by using digital electronics with no moving parts.

Lieutenant Herman Goldstine, who was the liaison between the United States Army and Moore School, picked up on the idea and asked Mauchly to write a formal proposal.

Following the course, Mauchly was hired as an instructor of electrical engineering and in 1943, he was promoted to assistant professor of electrical engineering.

Following the outbreak of World War II, the United States Army Ordnance Department contracted the Moore School to build an electronic computer which, as proposed by Mauchly and Eckert, would accelerate the recomputation of artillery firing tables.

In April 1943, the Army contracted with the Moore School to build the Electronic Numerical Integrator and Computer (ENIAC).

Mauchly led the conceptual design while Eckert led the hardware engineering on ENIAC.

A number of other talented engineers contributed to the confidential "Project PX".

Because of its high-speed calculations, ENIAC could solve problems that were previously unsolvable.

It was roughly a thousand times faster than the existing technology.

It could add 5,000 numbers or do 357 10-digit multiplications in one second.

ENIAC could be programmed to perform sequences and loops of addition, subtraction, multiplication, division, square-root, input/output functions, and conditional branches.

Programming was initially accomplished with patch cords and switches, and reprogramming took days.

Their work, as exposed in the widely read First Draft of a Report on the EDVAC (1945) and as taught in the Moore School Lectures (1946), influenced an explosion of computer development in the late 1940s all over the world.

In 1948, Mauchly married Kathleen Kay McNulty (1921–2006), one of the six original ENIAC programmers; they had five children Sara (Sallie), Kathleen (Kathy), John, Virginia (Gini), and Eva.

It was redesigned in 1948 to allow the use of stored programs with some loss in speed.

In 1959, Mauchly left Sperry Rand and started Mauchly Associates, Inc. One of Mauchly Associates' notable achievements was the development of the Critical Path Method (CPM) which provided for automated construction scheduling.

Mauchly also set up a consulting organization, Dynatrend, in 1967 and worked as a consultant to Sperry UNIVAC from 1973 until his death in 1980.

John Mauchly died on January 8, 1980, in Ambler, Pennsylvania, during heart surgery and following a long illness.

In 2002, for his work on ENIAC he was inducted, posthumously, into the National Inventors Hall of Fame.