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
UNIVAC I, the first commercial computer made in the
Together they started the first computer company, the Eckert-Mauchly
Computer Corporation (EMCC), and pioneered fundamental computer
concepts including the stored program, subroutines, and programming
languages. 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.
2 Moore School
4 The Moore School Lectures
9 Patent controversy
10 See also
12 Further reading
13 External links
John W. Mauchly was born on August 30, 1907, to Sebastian and Rachel
(Scheidermantel) 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
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. After
graduating from high school in 1925, he earned a scholarship to study
engineering at Johns Hopkins University. He subsequently transferred
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
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
University of Pennsylvania Moore School of
Electrical Engineering. There he met the lab instructor, J. Presper
Eckert (1919-1995), with whom he would form a long-standing working
partnership. 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
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 Abington, Pennsylvania,
during heart surgery and following a long illness. 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. 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
In 1941 Dr. 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
Main article: ENIAC
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. 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. It was redesigned in 1948 to allow the use of stored programs
with some loss in speed.
In 2002, for his work on
ENIAC he was inducted, posthumously, into the
National Inventors Hall of Fame.
ENIAC design was frozen in 1944 to allow construction. Eckert and
Mauchly were already aware of the limitations of the machine and began
plans on a second computer, to be called EDVAC. By January 1945 they
had procured a contract to build this stored-program computer. Eckert
had proposed a mercury delay line memory to store both program and
data. Later that year, mathematician
John von Neumann
John von Neumann learned of the
project and joined in some of the engineering discussions. He produced
what was understood to be an internal document describing the EDVAC.
The term von Neumann architecture arose from von Neumann's paper,
First Draft of a Report on the EDVAC. Dated June 30, 1945, it was
an early written account of a general purpose stored-program computing
machine (the EDVAC). Goldstine, in a move that was to become
controversial, removed any reference to Eckert or Mauchly and
distributed the document to a number of von Neumann's associates
across the country. The ideas became widely known within the very
small world of computer designers.
Besides the lack of credit, Eckert and Mauchly suffered additional
setbacks due to Goldstine's actions. The
ENIAC patent U.S. Patent
3,120,606, issued in 1964 was filed on June 26, 1947, and granted
February 4, 1964, but the public disclosure of design details of EDVAC
in the First Draft (which were also common to ENIAC) was later cited
as one cause for the 1973 invalidation of the
The Moore School Lectures
Main article: Moore School Lectures
In March 1946, just after the
ENIAC was announced, the Moore School
decided to change their patent policy, in order to gain commercial
rights to any future and past computer development there. Eckert and
Mauchly decided this was unacceptable; they resigned. However they had
already been contracted to do one more thing at the Moore School: to
give a series of talks on computer design.
The course "The Theory and Techniques for Design of Digital
Computers", ran from July 8 to August 31, 1946. Eckert gave 11 of the
lectures; Mauchly and Goldstine each delivered 6. "The Moore School
Lectures", as they came to be known, were attended by representatives
from the army, the navy, MIT, the National Bureau of Standards,
Cambridge University, Columbia, Harvard, the Institute for Advanced
Study, IBM, Bell Labs, Eastman Kodak, General Electric, and National
Cash Register. A number of the attendees were to later go on to
develop computers, such as Maurice Wilkes, of Cambridge, who built
In 1947 Eckert and Mauchly formed the first computer company, the
Eckert-Mauchly Computer Corporation
Eckert-Mauchly Computer Corporation (EMCC); Mauchly was president.
They secured a contract with the
National Bureau of Standards
National Bureau of Standards to build
EDVAC II", later named UNIVAC. UNIVAC, the first computer designed
for business applications, had many significant technical advantages
such as magnetic tape for mass storage. As an interim product, the
company created and delivered a smaller computer, BINAC, but were
still in a shaky financial situation. They were purchased by Remington
Rand and became the
Very early in the history of EMCC,
John Mauchly assumed responsibility
for programming, coding, and applications for the planned computer
systems. His early interaction with representatives of the Census
Bureau in 1944 and 1945, and discussion with people interested in
statistics, weather prediction, and various business problems in 1945
and 1946 focused his attention on the need to provide new users with
the software to accomplish their objectives. He knew it would be
difficult to sell computers without application materials, and without
training in how to use the systems. And so, EMCC began to assemble a
staff of mathematicians interested in coding in early 1947. (from
Mauchly’s interest lay in the application of computers, as well as
to their architecture and organization. His experience with
ENIAC and its successors led him to create Short Code
UNIVAC SHORT CODE"), the first programming language actually
used on a computer (predated by Zuse’s conceptual Plankalkul). It
was a pseudocode interpreter for mathematical problems proposed in
1949 and ran on the
UNIVAC I and II. Mauchly's belief in the
importance of languages led him to hire
Grace Murray Hopper
Grace Murray Hopper to develop
a compiler for the UNIVAC.
John Mauchly has also been credited for being the first one using the
verb "to program" in his 1942 paper on electronic computing, although
in the context of ENIAC, not in its current meaning.
Dr. Mauchly stayed involved in computers for the rest of his life. He
was a founding member and president of the Association for Computing
Machinery (ACM) and also helped found the Society for Industrial and
Applied Mathematics (SIAM), serving as its fourth president. The
Eckert-Mauchly Corporation was bought by
Remington Rand in 1950 and
for ten years Dr. Mauchly remained as Director of Univac Applications
Research. Leaving in 1959 he formed Mauchly Associates, a consulting
company that later introduced the critical path method (CPM) for
construction scheduling by computer. In 1967 he founded Dynatrend, a
computer consulting organization. In 1973 he became a consultant to
Mauchly received numerous award and honors. He was a life member of
the Franklin Institute, the
National Academy of Engineering
National Academy of Engineering and the
Society for Advancement of Management. He was elected a Fellow of the
IRE, a predecessor society of IEEE, in 1957, and was a Fellow of the
American Statistical Association. He received an LLD (Hon) degree from
University of Pennsylvania
University of Pennsylvania and aDSc(Hon) degree from Ursinus
College. He was a recipient of the Philadelphia Award, the Scott
Medal, the Goode Medal of AFIPS (American Federation of Information
Processing Societies), the Pennsylvania Award, the Emanual R. Piore
Award, the Howard N. Potts Medal, and numerous other awards.
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Mauchly and Eckert's patent on the
ENIAC was invalidated by U.S.
Federal Court decision in October, 1973 for several reasons. Some had
to do with the time between publication (the First Draft) and the
patent filing date (1947). The federal judge who presided over the
case ruled that "the subject matter was derived" from the earlier
Atanasoff–Berry Computer (ABC). This statement has become the center
of a controversy.
Critics note that while the court said that the ABC was the first
electronic digital computer, it did not define the term computer. It
had originally referred to a person who computes, but was adapted to
apply to a machine.
Critics of the court decision also note that there is, at a component
level, nothing in common between the two machines. The ABC was binary;
ENIAC was decimal. The ABC used regenerative drum memory; The
ENIAC used electronic decade counters. The ABC used its tubes to
implement a binary serial adder while the
ENIAC used tubes to
implement a complete set of decimal operations. The ENIAC's
general-purpose instruction set, together with the ability to
automatically sequence through them, made it a general-purpose
Proponents for the court decision emphasize that the testimony
established that Mauchly definitely had complete access to Atanasoff's
machine and the documents describing it. Letters he wrote to Atanasoff
show that he was at one time at least considering building on
Mauchly consistently maintained that it was the use of high-speed
electronic flip-flops in cosmic-ray counting devices at Swarthmore
College that gave him the idea for computing at electronic speeds.
Mauchly's sphericity test
List of pioneers in computer science
^ The Use of High-Speed Vacuum Tube Devices for Calculating (by John
W. Mauchly, August 1942)
National Inventors Hall of Fame
National Inventors Hall of Fame Archived 2013-08-24 at the Wayback
^  Archived February 22, 2012, at the Wayback Machine.
McCartney, Scott (1999). ENIAC: The Triumphs and Tragedies of the
World's First Computer. Walker & Co.
Shurkin, Joel N. (1996). Engines of the Mind: The Evolution of the
Computer from Mainframes to Microprocessors. W. W. Norton.
Antonelli, Kathleen R. (April 1984). "John Mauchly's Early Years".
Annals of the History of Computing. 6 (2): 116–138.
Stern, Nancy (1981). From
ENIAC to UNIVAC: An Appraisal of the
Eckert-Mauchly Computers. Bedford, Massachusetts: Digital Press.
Norberg, Arthur L. (2005-06-01). Computers and Commerce: A Study of
Technology and Management at Eckert-Mauchly
Engineering Research Associates, and Remington Rand, 1946-1957. The
MIT Press. ISBN 0-262-14090-X.
Lukoff, Herman (1979). From Dits to Bits: A personal history of the
electronic computer. Portland, Oregon, USA: Robotics Press.
ISBN 0-89661-002-0. LCCN 79-90567.
Oral history interview with
J. Presper Eckert at Charles Babbage
Institute, University of Minnesota, Minneapolis. Eckert, a co-inventor
of the ENIAC, discusses its development at the University of
Pennsylvania and the interaction of the personnel at the Moore School.
John W. Mauchly and the Development of the
Computer - by Asaf
Goldschmidt and Atsushi Akera, An Exhibition in the Department of
Special Collections Van Pelt Library, University of Pennsylvania
Computer and the Skateboard. The only work to contain
archival footage of
John Mauchly speaking about the development of the
O'Connor, John J.; Robertson, Edmund F., "John Mauchly", MacTutor
History of Mathematics archive, University of St Andrews .
ISNI: 0000 0000 5073 6324