George Stibitz

George Robert Stibitz (April 30, 1904[1] – January 31, 1995[2]) was a Bell Labs researcher internationally recognized as one of the fathers of the modern first digital computer. He was known for his work in the 1930s and 1940s on the realization of Boolean logic digital circuits using electromechanical relays as the switching element.

Stibitz was born in York, Pennsylvania. He received his bachelor's degree from Denison University in Granville, Ohio, his master's degree from Union College in 1927, and his Ph.D. in mathematical physics in 1930 from Cornell University.

George Stibitz
George Stibitz
BornApril 30, 1904
DiedJanuary 31, 1995 (aged 90)
Alma materCornell University
Union College
Denison University
AwardsHarry H. Goode Memorial Award (1965)
IEEE Emanuel R. Piore Award (1977)


Stibitz plaque 0708 edited-1
This bronze plaque is located in the entryway of McNutt Hall at Dartmouth College reads, "In this building on September 9, 1940, George Robert Stibitz, then a mathematician with bell telephone laboratories, first demonstrated the remote operation of an electrical digital computer. Stibitz, who conceived the electrical digital computer in 1937 at Bell Labs, described his invention of the "complex number calculator" at a meeting of the Mathematical Association of America held here. Members of the audience transmitted problems to the computer at Bell Labs in New York City, and in seconds received solutions transmitted from the computer to a teletypewriter in this hall."
Stibitz McNutt Hall Dartmouth 0709 edited-1
The site of the first long-distance communication of man and computer: McNutt Hall at Dartmouth College, September 9, 1940. The bronze commemorative plaque is mounted on the left wall in the entryway of the hall.

In November 1937, George Stibitz, then working at Bell Labs (1930-1941),[3] completed a relay-based calculator he later dubbed the "Model K" (for "kitchen table", on which he had assembled it), which calculated using binary addition.[4] Replicas of the "Model K" now reside in the Computer History Museum, the Smithsonian Institution, the William Howard Doane Library at Denison University and the American Computer Museum in Bozeman, Montana, where the George R. Stibitz Computer and Communications Pioneer Awards are granted.

Bell Labs subsequently authorized a full research program in late 1938 with Stibitz at the helm. Their Complex Number Computer, completed in November 1939 and put into operation in 1940, was able to do calculations on complex numbers.[5] In a demonstration to the American Mathematical Society conference at Dartmouth College in September 1940, Stibitz used a modified teletype to send commands to the Complex Number Computer in New York over telegraph lines.[6][7] It was the first computing machine ever used remotely.[8] (See the commemorative plaque and the hall where this event took place in the photos below.)

Wartime activities and subsequent Bell Labs computers

After the United States entered World War II in December, 1941, Bell Labs became active in developing fire-control devices for the U.S. military. The Labs' most famous invention was the M-9 Gun Director,[9] an ingenious analog device that directed anti-aircraft fire with uncanny accuracy.[10] Stibitz moved to the National Defense Research Committee, an advisory body for the government, but he kept close ties with Bell Labs. For the next several years (1941-1945),[3] with his guidance, the Labs developed relay computers of ever-increasing sophistication. The first of them was used to test the M-9 Gun Director. Later models had more sophisticated capabilities. They had specialized names, but later on, Bell Labs renamed them "Model II," "Model III," etc., and the Complex Number Computer was renamed the "Model I." All used telephone relays for logic, and paper tape for sequencing and control. The "Model V", was completed in 1946 and was a fully programmable, general-purpose computer, although its relay technology made it slower than the all-electronic computers then under development.[11]

After the war, in 1945, Stibitz didn't returns to Bell Labs, but instead went into private consulting work.[12][3]

Origin of the term "digital"

In April, 1942, Stibitz attended a meeting of a division of the Office of Scientific Research and Development (OSRD), charged with evaluating various proposals for fire-control devices to be used against Axis forces during World War II. Stibitz noted that the proposals fell into two broad categories: "analog" and "pulse." In a memo written after the meeting, he suggested that the term "digital" be used in place of "pulse," as he felt the latter term was insufficiently descriptive of the nature of the processes involved. The word "digit" at the time had two common meanings: the ten fingers of one's hands, and the numbers 0 through 9. The adjective "digital" was also in use, although it was not as common. For example, among physicians, a "digital" examination referred to the use of a doctor's finger to palpate part of the body. Stibitz's memorandum was the first known use of the term "digital" to refer to calculating machinery.[13]


Stibitz held 38 patents, in addition to those he earned at Bell Labs. He became a member of the faculty at Dartmouth College in 1964 to build bridges between the fields of computing and medicine, and retired from research in 1983.

Computer art

In his later years, Stibitz "turned to non-verbal uses of the computer". Specifically, he used a Commodore-Amiga to create computer art. In a 1990 letter, written to the department chair of the Mathematics and Computer Science department of Denison University he said:

I have turned to non-verbal uses of the computer, and have made a display of computer "art". The quotes are obligatory, for the result of my efforts is not to create important art but to show that this activity is fun, much as the creation of computers was fifty years ago.

The Mathematics and Computer Science department at Denison University has enlarged and displayed some of his artwork.


  • Stibitz, George; Larrivee, Jules A. (1957). Mathematics and Computers. New York: McGraw-Hill.

See also


  1. ^ Henry S. Tropp, "Stibitz, George Robert," in Anthony Ralston and Edwin D. Reilly, eds., Encyclopedia of Computer Science, Third Edition (New York: van Nostrand Rheinhold, 1993), pp. 1284–1286. Some accounts give April 20 as his birth date, but the Tropp citation is the most authoritative.
  2. ^ Saxon, Wolfgang. "Dr. George Stibitz, 90, Inventor Of First Digital Computer in '40". Retrieved 2018-09-07.
  3. ^ a b c "Computer Pioneers - George Robert Stibitz".
  4. ^ Ritchie, David (1986). The Computer Pioneers. New York: Simon and Schuster. p. 35. ISBN 067152397X.
  5. ^ Ritchie 1986, p. 38.
  6. ^ Ritchie 1986, p. 39.
  7. ^ Metropolis, Nicholas (2014-06-28). History of Computing in the Twentieth Century. Elsevier. p. 481. ISBN 9781483296685.
  8. ^ Dalakov, Georgi. "Relay computers of George Stibitz". History of Computers: Hardware, Software, Internet. Retrieved 30 March 2015.
  9. ^ "BLOW HOT-BLOW COLD - The M9 never failed". BELL LABORATORIES RECORD. XXIV (12): 454–456. Dec 1946.
  10. ^ Eames, office of Charles and Ray, A Computer Perspective: Background to the Computer Age (Cambridge, MA: Harvard University Press 1973, 1990), p. 128
  11. ^ Ceruzzi, Paul E. (1983). "4. Number, Please - Computers at Bell Labs". Reckoners: The Prehistory of the Digital Computer, from Relays to the Stored Program Concept, 1935-1945. Greenwood Publishing Group, Incorporated. ISBN 9780313233821.
  12. ^ "The relay computers at Bell Labs : those were the machines, part 2". Datamation. The relay computers at Bell Labs : those were the machines, parts 1 and 2 | 102724647 | Computer History Museum. part 2: pp. 49. May 1967. After the time that the designs for Model V were completed I resigned from Bell Labs to go into independent consulting work.
  13. ^ Bernard O. Williams, "Computing with Electricity, 1935-1945," PhD Dissertation, University of Kansas, 1984 (University Microfilms International, 1987), p. 310


  • Melina Hill, Valley News Correspondent, A Tinkerer Gets a Place in History, Valley News West Lebanon NH, Thursday March 31, 1983, page 13.
  • Brian Randall, ed. The Origins of Digital Computers: Selected Papers (Berlin, Heidelberg, New York: Springer-Verlag, 1975), pp. 237–286.
  • Andrew Hodges (1983), Alan Turing: The Enigma, Simon and Schuster, New York, ISBN 0-671-49207-1. Stibitz is mentioned briefly on pages 299 and 326. Hodges refers to Stibitz's machine as one of two "big relay calculators" (Howard H. Aiken's being the other one, p. 326).
"The second American project [Aiken's being the first] was underway at Bell Laboratories. Here the engineer G. Stibitz had first only thought of designing relay machines to perform decimal arithmetic with complex numbers, but after the outbreak of war had incorporated the facility to carry out a fixed sequence of arithmetical operations. His 'Model III' [sic] was under way in the New York building at the time of Alan Turing's stay there, but it had not drawn his attention." (p. 299)
Stibitz's work with binary addition has a peculiar (i.e. apparently simultaneous) overlap with some experimenting Alan Turing did in 1937 while a PhD student at Princeton. The following is according to a Dr. Malcolm McPhail "who became involved in a sideline that Alan took up" (p. 137); Turing built his own relays and "actually designed an electric multiplier and built the first three or four stages to see if it could be made to work" (p. 138). It is unknown whether Stibitz and/or McPhail had any influence on this work of Turing's; McPhail's implication is that Turing's "[alarm]about a possible war with Germany" (p. 138) caused him to become interested in cryptanalysis, and this interest led to discussions with McPhail, and these discussions led to the relay-multiplier experiments (the pertinent part of McPhail's letter to Hodges is quoted in Hodges p. 138).
  • Ritchie, David (1986). "George Stibitz and the Bell Computers". The Computer Pioneers. New York: Simon and Schuster. pp. 33–52. ISBN 067152397X.
  • Smiley, Jane, The Man Who Invented the Computer: The Biography of John Atanasoff, Digital Pioneer, Random House Digital, Inc., 2010. ISBN 978-0-385-52713-2.

External links



1940 in science

The year 1940 in science and technology involved some significant events, listed below.

Bell-Northern Research

Bell-Northern Research (BNR) was a telecommunications research and development company established In 1971 when Bell Canada and Northern Electric combined their R&D organizations. It was jointly owned by Bell Canada and Northern Telecom. BNR was absorbed into Nortel Networks when that company changed its name from Northern Telecom in the mid-1990s.

BNR was based at the Carling Campus in Ottawa, Ontario, Canada, with campuses at locations around the world, including Research Triangle Park, North Carolina; Richardson, Texas; and Maidenhead, United Kingdom. Bell-Northern Research pioneered the development of digital technology, and created the first practical digital PBX, (SL1), and central office (DMS). Under the direction of then Nortel Chief Officer, John Roth, BNR lost its separate identity in the 1990s, and was folded into the Nortel R&D organization.

Binary code

A binary code represents text, computer processor instructions, or any other data using a two-symbol system. The two-symbol system used is often "0" and "1" from the binary number system. The binary code assigns a pattern of binary digits, also known as bits, to each character, instruction, etc. For example, a binary string of eight bits can represent any of 256 possible values and can, therefore, represent a wide variety of different items.

In computing and telecommunications, binary codes are used for various methods of encoding data, such as character strings, into bit strings. Those methods may use fixed-width or variable-width strings. In a fixed-width binary code, each letter, digit, or other character is represented by a bit string of the same length; that bit string, interpreted as a binary number, is usually displayed in code tables in octal, decimal or hexadecimal notation. There are many character sets and many character encodings for them.

A bit string, interpreted as a binary number, can be translated into a decimal number. For example, the lower case a, if represented by the bit string 01100001 (as it is in the standard ASCII code), can also be represented as the decimal number "97".

Binary number

In mathematics and digital electronics, a binary number is a number expressed in the base-2 numeral system or binary numeral system, which uses only two symbols: typically "0" (zero) and "1" (one).

The base-2 numeral system is a positional notation with a radix of 2. Each digit is referred to as a bit. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used by almost all modern computers and computer-based devices.

Digital data

Digital data, in information theory and information systems, is the discrete, discontinuous representation of information or works. Numbers and letters are commonly used representations.

Digital data can be contrasted with analog signals which behave in a continuous manner, and with continuous functions such as sounds, images, and other measurements.

The word digital comes from the same source as the words digit and digitus (the Latin word for finger), as fingers are often used for discrete counting. Mathematician George Stibitz of Bell Telephone Laboratories used the word digital in reference to the fast electric pulses emitted by a device designed to aim and fire anti-aircraft guns in 1942. The term is most commonly used in computing and electronics, especially where real-world information is converted to binary numeric form as in digital audio and digital photography.

Digital transformation

Digital Transformation (DX) is the novel use of digital technology to solve traditional problems. These digital solutions enable inherently new types of innovation and creativity, rather than simply enhance and support traditional methods.In a narrower sense, "digital transformation" may refer to the concept of "going paperless" or reaching a "digital business maturity" affecting both individual businesses and whole segments of society, such as government, mass communications, art, medicine, and science.The digital transformation is already underway, but is not proceeding at the same pace everywhere. According to the McKinsey Global Institute's Industry Digitization Index, Europe is currently operating at 12% of its digital potential, while the USA is operating at 18%. Within Europe, Germany operates at 10% of its digital potential, while the UK is almost on par with the US at 17%.

Euler diagram

An Euler diagram (/ˈɔɪlər/, OY-lər) is a diagrammatic means of representing sets and their relationships. Typically they involve overlapping shapes, and may be scaled, such that the area of the shape is proportional to the number of elements it contains. They are particularly useful for explaining complex hierarchies and overlapping definitions. They are often confused with Venn diagrams. Unlike Venn diagrams, which show all possible relations between different sets, the Euler diagram shows only relevant relationships.

The first use of "Eulerian circles" is commonly attributed to Swiss mathematician Leonhard Euler (1707–1783). In the United States, both Venn and Euler diagrams were incorporated as part of instruction in set theory as part of the new math movement of the 1960s. Since then, they have also been adopted by other curriculum fields such as reading as well as organizations and businesses.

Euler diagrams consist of simple closed shapes in a two dimensional plane that each depict a set or category. How or if these shapes overlap demonstrates the relationships between the sets. There are only 3 possible relationships between any 2 sets; completely inclusive, partially inclusive, and exclusive. This is also referred to as containment, overlap or neither or, especially in mathematics, it may be referred to as subset, intersection and disjoint.

Each Euler curve divides the plane into two regions or "zones": the interior, which symbolically represents the elements of the set, and the exterior, which represents all elements that are not members of the set. Curves whose interior zones do not intersect represent disjoint sets. Two curves whose interior zones intersect represent sets that have common elements; the zone inside both curves represents the set of elements common to both sets (the intersection of the sets). A curve that is contained completely within the interior zone of another represents a subset of it.

Venn diagrams are a more restrictive form of Euler diagrams. A Venn diagram must contain all 2n logically possible zones of overlap between its n curves, representing all combinations of inclusion/exclusion of its constituent sets. Regions not part of the set are indicated by coloring them black, in contrast to Euler diagrams, where membership in the set is indicated by overlap as well as color. When the number of sets grows beyond 3 a Venn diagram becomes visually complex, especially compared to the corresponding Euler diagram. The difference between Euler and Venn diagrams can be seen in the following example. Take the three sets:

The Euler and the Venn diagrams of those sets are:

In a logical setting, one can use model theoretic semantics to interpret Euler diagrams, within a universe of discourse. In the examples below, the Euler diagram depicts that the sets Animal and Mineral are disjoint since the corresponding curves are disjoint, and also that the set Four Legs is a subset of the set of Animals. The Venn diagram, which uses the same categories of Animal, Mineral, and Four Legs, does not encapsulate these relationships. Traditionally the emptiness of a set in Venn diagrams is depicted by shading in the region. Euler diagrams represent emptiness either by shading or by the absence of a region.

Often a set of well-formedness conditions are imposed; these are topological or geometric constraints imposed on the structure of the diagram. For example, connectedness of zones might be enforced, or concurrency of curves or multiple points might be banned, as might tangential intersection of curves. In the adjacent diagram, examples of small Venn diagrams are transformed into Euler diagrams by sequences of transformations; some of the intermediate diagrams have concurrency of curves. However, this sort of transformation of a Venn diagram with shading into an Euler diagram without shading is not always possible. There are examples of Euler diagrams with 9 sets that are not drawable using simple closed curves without the creation of unwanted zones since they would have to have non-planar dual graphs.


Excess-3, 3-excess or 10-excess-3 binary code (often abbreviated as XS-3, 3XS or X3) or Stibitz code (after George Stibitz, who built a relay-based adding machine in 1937) is a self-complementary binary-coded decimal (BCD) code and numeral system. It is a biased representation. Excess-3 code was used on some older computers as well as in cash registers and hand-held portable electronic calculators of the 1970s, among other uses.

Harry H. Goode Memorial Award

The Harry H. Goode Memorial Award is an IEEE Computer Society annual awards in honor of Harry H. Goode for achievements in the information processing field which are considered either a single contribution of theory, design, or technique of outstanding significance, or the accumulation of important contributions on theory or practice over an extended time period, the total of which represent an outstanding contribution.

History of telecommunication

The history of telecommunication began with the use of smoke signals and drums in Africa, the Americas and parts of Asia. In the 1790s, the first fixed semaphore systems emerged in Europe; however it was not until the 1830s that electrical telecommunication systems started to appear. This article details the history of telecommunication and the individuals who helped make telecommunication systems what they are today. The history of telecommunication is an important part of the larger history of communication.

IEEE Emanuel R. Piore Award

The IEEE Emanuel R. Piore Award is a Technical Field Award given each year by the IEEE to an individual or team of two people who have made outstanding contributions to information processing systems in relation to computer science. The award is named in honor of Emanuel R. Piore.

The award was established in 1976. It could be presented to an individual or team of two.

Recipients of this award received a bronze medal, certificate, and honorarium.This award was discontinued by the IEEE Board of Directors in 2012.

Konrad Zuse

Konrad Zuse (German: [ˈkɔnʁat ˈtsuːzə]; 22 June 1910 – 18 December 1995) was a German civil engineer, inventor and computer pioneer. His greatest achievement was the world's first programmable computer; the functional program-controlled Turing-complete Z3 became operational in May 1941. Thanks to this machine and its predecessors, Zuse has often been regarded as the inventor of the modern computer.Zuse was also noted for the S2 computing machine, considered the first process control computer. He founded one of the earliest computer businesses in 1941, producing the Z4, which became the world's first commercial computer. From 1943 to 1945 he designed the first high-level programming language, Plankalkül. In 1969, Zuse suggested the concept of a computation-based universe in his book Rechnender Raum (Calculating Space).

Much of his early work was financed by his family and commerce, but after 1939 he was given resources by the Nazi German government. Due to World War II, Zuse's work went largely unnoticed in the United Kingdom and the United States. Possibly his first documented influence on a US company was IBM's option on his patents in 1946.

There is a replica of the Z3, as well as the original Z4, in the Deutsches Museum in Munich. The Deutsches Technikmuseum in Berlin has an exhibition devoted to Zuse, displaying twelve of his machines, including a replica of the Z1 and several of Zuse's paintings.

List of Denison University alumni

This is a list of notable alumni of Denison University in Granville, Ohio.

List of people from York, Pennsylvania

The following people were all born in, residents of, or otherwise closely associated with York, Pennsylvania.

John Adlum (1759–1836), pioneer viticulturist

Dominick Argento (born 1927), music composer

Bruce Arians (born 1952), head coach for the NFL's Tampa Bay Buccaneers

Charles Augustus Barnitz (1780–1850), politician

Will Beatty (born 1985), offensive tackle, New York Giants (2009–16), Super Bowl XLVI champion

Andrew R. Brodbeck (1860–1937), politician

Edward Schroeder Brooks (1867–1957), politician

Omar Brown (born 1975), gridiron football player

John Hull Campbell (1800–1868), U.S. Congressman for Pennsylvania's 3rd congressional district, 1845–1847

Blaine Capatch (born 1965), comedian

Loretta Claiborne (born c. 1953), Special Olympics World Games multi-gold medalist and recipient of the 1996 ESPY Arthur Ashe Courage Award

Herbert B. Cohen (1900–1970), Pennsylvania Supreme Court justice

Nathaniel N. Craley, Jr. (1927–2006), politician

Patrick Dahlheimer (born 1971), bass guitarist

Sheila Darcy (1914–2004), actress

Phineas Davis (1792–1835), clockmaker and inventor

John A. Dempwolf (1848–1926), architect

Jacob L. Devers (1887–1979), World War II U.S. Army general

Neal Dodson (born 1978), award-winning feature film producer of All Is Lost & Broadway actor

Chris Doleman (born 1961), NFL defensive end

John Durang (1768–1822), dancer and musician

Luther P. Eisenhart (1876–1965), mathematician

Stephen Etnier (1903–1984), artist

James Ewing (1736–1806), Pennsylvania statesman

William Henry Farquhar (1813–1887), developmental influencer of Montgomery County, Maryland

William B. Franklin (1823–1903), American Civil War general

Sam Freed (born 1948), actor

James Gerry (1896–1973), politician

Hugh Glasgow (1769–1818), politician, judge

William C. Goodridge (1805–1873), barber, merchant, Underground Railroad activist

Chad Gracey (born 1971), drummer

Halestorm (formed 1997), hard rock band

Mahlon Haines (1875–1962), businessman and philanthropist

Granville O. Haller (1819–1897), American Civil War officer who led the defense of Adams and York counties during the Gettysburg Campaign and later became a leading Seattle millionaire

Mike Hawthorne (born 1975/1976), comic book and graphic novel illustrator

Bob Hoffman (1898–1985), founder of York Barbell; considered the "father of American weightlifting"

David Holmes (1769–1832), politician

Jerry Howarth (born 1946), MLB announcer, voice of the Toronto Blue Jays

Lois Hunt (1925–2009), soprano opera singer who toured for decades with baritone Earl Wrightson

Carolina Isakson Proctor (1930–2012), First Lady of Colombia

Kevin Jones (born 1967), BMX rider

Brian Keene (born 1967), best-selling novelist and comic book writer

James Kelly (1760–1819), U.S. representative

Matthew Knisely (born 1974), TV photojournalist

Jeff Koons (born 1955), artist

Ed Kowalczyk (born 1971), musician, lead singer of the band Live

John Kuhn (born 1982), NFL fullback

George M. Leader (1918–2013), 36th Governor of Pennsylvania

Ernest W. Lefever (1919–2009), foreign affairs expert

Samuel S. Lewis (1874–1959), former Pennsylvania lieutenant governor

Sylvia Lewis (born 1931), dancer and actress

Live (1988–2009; re-formed 2011), alternative rock band

Ken Ludwig (born 1950), playwright and theatre director

Martie Maguire (born 1969), member of the country band Dixie Chicks

Frances Lee McCain (born 1944), actress (Gremlins, Footloose, Back to the Future)

Del McCoury (born 1939), bluegrass musician

Gary Miller (born 1946), conductor and gay activist

Lewis Miller (1796–1882), artist and chronicler of early 19th-century life in York

Cameron Mitchell (1918–1994), actor

Walt Partymiller (1912–1991), cartoonist

Todd Platts (born 1962), politician

The Quin-Tones (1957–1960; 1986–1990s), a doo-wop group

Ken Raffensberger (1917–2002), winning pitcher of 1944 Major League Baseball All-Star Game

Charles H. Robertson (1934–2017), politician

Chris Roupas (born 1957), Greek-American former basketball player

Wayne Schafer (born 1963), pitmaster

Harry E. Seyler (1908–1994), politician and educator

Evan Sharp (born 1982), co-founder of Pinterest, graduated York Suburban High School 2001

Craig Sheffer (born 1960), actor, Nightbreed (1990), A River Runs Through It (1992) and The Program (1993)

Edgar Fahs Smith (1854–1928), scientist, chemist, historian

James Smith (1719–1806), signer of the Declaration of Independence; lived on South George Street and is buried in York

George Stibitz (1904–1995), Bell Labs researcher and digital pioneer

John Terpak (1912–1993), champion weightlifter, York Barbell executive

Vic Wertz (1947–1963), professional baseball player

Rebecca Wisocky (born 1971), television and stage actress

Tom Wolf (born 1948), 47th Governor of Pennsylvania

Butch Wynegar (born 1956), major league baseball player

Martin Cooper (inventor)

Martin "Marty" Cooper (born December 26, 1928) is an American engineer. He is a pioneer in the wireless communications industry, especially in radio spectrum management, with eleven patents in the field.While at Motorola in the 1970s, Cooper invented the first handheld cellular mobile phone (distinct from the car phone) in 1973 and led the team that developed it and brought it to market in 1983. He is considered the "father of the (handheld) cell phone" and is also cited as the first person in history to make a handheld cellular phone call in public.Cooper is co-founder of numerous communications companies with his wife and business partner Arlene Harris; He is co-founder and current Chairman of Dyna LLC, in Del Mar, California. Cooper also sits on committees supporting the U.S. Federal Communications Commission and the United States Department of Commerce.

Mechanical computer

A mechanical computer is built from mechanical components such as levers and gears, rather than electronic components. The most common examples are adding machines and mechanical counters, which use the turning of gears to increment output displays. More complex examples could carry out multiplication and division—Friden used a moving head which paused at each column—and even differential analysis. One model sold in the 1960s calculated square roots.

Mechanical computers can be either analog, using smooth mechanisms such as curved plates or slide rules for computations; or digital, which use gears.

Mechanical computers reached their zenith during World War II, when they formed the basis of complex bombsights including the Norden, as well as the similar devices for ship computations such as the US Torpedo Data Computer or British Admiralty Fire Control Table. Noteworthy are mechanical flight instruments for early spacecraft, which provided their computed output not in the form of digits, but through the displacements of indicator surfaces. From Yuri Gagarin's first manned spaceflight until 2002, every manned Soviet and Russian spacecraft Vostok, Voskhod and Soyuz was equipped with a Globus instrument showing the apparent movement of the Earth under the spacecraft through the displacement of a miniature terrestrial globe, plus latitude and longitude indicators.

Mechanical computers continued to be used into the 1960s, but were quickly replaced by electronic calculators, which—with cathode-ray tube output—emerged in the mid-1960s. The evolution culminated in the 1970s with the introduction of inexpensive handheld electronic calculators. Mechanical computers were ailing in the 1970s and dead by the 1980s.

In 2016, NASA announced that its Automaton Rover for Extreme Environments program would use a mechanical computer to operate in the harsh environmental conditions found on Venus.

Model V

The Model V was among the early electromechanical general purpose computers, designed by George Stibitz and built by Bell Telephone Laboratories, operational in 1946.

Only two machines were built: first one was installed at National Advisory Committee for Aeronautics, second (1947) at Ballistic Research Laboratory (BRL).

September 9

September 9 is the 252nd day of the year (253rd in leap years) in the Gregorian calendar. 113 days remain until the end of the year.


Telecommunication is the transmission of signs, signals, messages, words, writings, images and sounds or information of any nature by wire, radio, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology. It is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. Such transmission paths are often divided into communication channels which afford the advantages of multiplexing. Since the Latin term communicatio is considered the social process of information exchange, the term telecommunications is often used in its plural form because it involves many different technologies.Early means of communicating over a distance included visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs. Other examples of pre-modern long-distance communication included audio messages such as coded drumbeats, lung-blown horns, and loud whistles. 20th- and 21st-century technologies for long-distance communication usually involve electrical and electromagnetic technologies, such as telegraph, telephone, and teleprinter, networks, radio, microwave transmission, fiber optics, and communications satellites.

A revolution in wireless communication began in the first decade of the 20th century with the pioneering developments in radio communications by Guglielmo Marconi, who won the Nobel Prize in Physics in 1909, and other notable pioneering inventors and developers in the field of electrical and electronic telecommunications. These included Charles Wheatstone and Samuel Morse (inventors of the telegraph), Alexander Graham Bell (inventor of the telephone), Edwin Armstrong and Lee de Forest (inventors of radio), as well as Vladimir K. Zworykin, John Logie Baird and Philo Farnsworth (some of the inventors of television).

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.