People in the History of Computing


Modern computers have their roots in the Renaissance and Industrial Revolution. Here are some but by no means all of the individuals involved in the chain of development leading to the computers that you will be using in this course.

Galileo introduced the idea that the physical world could be modeled with mathematics (about 1600).

John Napier introduced the concept of logarithms in 1617, converting the process of multiplication to the simpler process of addition..

William Oughtred was a clergyman who invented the Slide Rule (simple way to use logarithms). It is a simple analog computer. The first commercial model was introduced in 1621, and it was used during the 350 years of dark ages before the invention of the electronic calculator.

Wilhelm Schickard built a digital machine capable addition subtraction, multiplication, and division (the last two only partially automatically) in 1623. He and family were killed in the plagues of the 30 years war. Because his work was lost for many years, he became a historical footnote.

Blaise Pascal built a mechanical adding machine in 1642.

Gottfried Leibniz invented the Leibniz Wheel in about 1670, which allowed the construction of a machine that could add, subtract, multiply and divide. The design formed the basis of mechanical calculators used into the 1960's. Primary applications for this and similar devices were tidal tables, tables of planetary motions, ballistics calculations, and the creation of Log and Trig tables. I used one of these beasts to analyze data in an undergraduate physics laboratory. The noises were interesting, but speed was very poor compared to electronic calculators.

Joseph Jacquard developed an automated loom in 1805, weaving patterns were determined by holes in a card.

Charles Babbage was responsible for the first fully automated computer design. He designed but never fully completed a non-automated 20 decimal Difference Engine between 1823 and 1842. In 1834 he came up with an idea for the first programmable digital computer called the Analytic Engine (a mechanical device). He refined the design during the remainder of his life, but never completed implementation of the design. It was capable of one operation per second and programmed by card input.

Pehr Scheutz Built a fully functional version of Babbage's Difference Engine in 1854. It included a built in printer. The device is now in the Smithsonian.

Augusta Ada Byron documented Babbage's work on the Analytic Engine, suggested improvements, and designed programs for the device. She is credited as being the first computer programmer. Some believe that the Analytic Engine would have been completed if she had not died in 1852 at age 36.

John Billings in a conversation with Herman Hollerith noted that the census results should be tabulated with machines. This comment resulted from the extremely long time required to compile the 1880 U.S. census (finished in 1887).

Herman Hollerith left the census bureau and obtained patents for counting machines in 1889. He beat his competitors in a competition to tabulate 1890 census data, using the first truly electronic computing machinery. Data was entered as holes in cards the size of a dollar bill, and electric current through selected holes triggered a counter or sorter. He created the Tabulating Machine Company which later merged with a number of other companies to become the Computing Tabulating and Recording company. In 1924 Thomas J. Watson (the chief executive officer) changed the company's name to International Business Machines.

James Powers created a competing tabulating firm in 1911, Powers Tabulating Machine Company, and undersold Hollerith with superior equipment. He introduced the electric card punch. The company merged with Remington-Rand in 1927, with Sperry Gyroscope in 1955, and is now Unisys. Employees eventually spawned Control Data Corporation and later Cray Research.

Vannevar Bush built a programmable analog computer in 1930. It was limited to the solution of differential equations, and based on previous work by Lord Kelvin. However, the device was mainly mechanical (gears, wheels, and rods).

Claude Shannon laid the groundwork for modern digital computers in 1930. Using the logical theory of Boole, Whitehead and Russell, he showed how to construct adders, multipliers, etc. from simple logical units, creating computers operating in the binary number system.

John Atanasoff and Clifford Berry applied this theory in 1940 using 300 vacuum tubes as switches. Atanasoff demonstrated his developments to John Mauchly ( below), and was declared the inventor of the modern Digital Computer by a court on Oct 19, 1973.

Howard Aiken was responsible for the Mark I Electronic Brain jointly developed by Harvard and IBM. He thought that vacuum tubes were too unreliable so used solenoids. Input was on paper tape or cards and it could perform 1 multiplication per second. He gave Grace Hopper her first job.

John Mauchly and J.P. Eckert developed the ENIAC based on vacuum tubes at the University of Pennsylvania Moore School. It performed 5000 adds per second, and programming was done by rewiring patch panels. They formed a private company due to patent disputes with the University and developed the BINAC. It only did 2500 adds per second, but programming was supplied to the machine via the input data stream. This was followed by the UNIVAC which was delivered to the Census Bureau in 1951. Input was on Magnetic Tape, and it was sold by Remington-Rand. This was this fastest computer of its time and became famous for predicting Eisenhower's 1952 victory with 7% of the vote tallied. They lost key patent disputes to Atanasoff.

William Shockley, John Bardeen, and Walter Brattain invented the Transistor in 1947. The first reliable junction transistor was built in 1951 and the first transistor computers in 1957. They started Silicon Valley in 1955 with Shockley Semi-Conductor.

Grace Hopper obtained a PhD in mathematics in 1934 and joined the Navy in 1943 at age 37. She programmed the Mark 1, and wrote the Flow-Matic compiler for the Univac in 1957, which formed the basis of COBAL, the dominant language in business computing.

Gene Amdahl and Seymour Cray dominated the design of large computers from the late 50's trough the early 80's, Cray with CDC and Amdahl with IBM. Cray introduced RISC technology, and founded the CRAY Computer Company, building the fastest and most reliable computer of its time (mid 1970's) .

Robert Noyce and Jack Kilby Separately developed the first integrated circuits in 1958. Noyce started with Shockley and helped found Fairchild semiconductor and INTEL. Kilby developed the first electronic calculator in 1966 (not marketed until 1971). Integrated circuits have gone from a few (<10) to many million transistors on a quarter inch chip of silicon in 30 years.

Marcian Hoff built the first computer on a chip in 1969, the INTEL 4004, a bit microprocessor based loosely on DEC's PDP 8. It was first sold to a Japanese company for a calculator and contained 2300 transistors. It was produced in 1971, and succeeded by the 8008, then the 8080. The current chip in this line of evolution is the INTEL Pentium.

Gary Kildall taught computer science at the Naval Post Graduate School. He developed a PL/I compiler for the 4004 and later developed the CP/M operating system for 8080 and the Z80 processor series. He lost an operating system contract with IBM to Microsoft which copied his operating system, naming it MS-DOS.

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Maintained by John Mahaffy : jhm@cac.psu.edu