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GENIAC Electric Brain
Geniac was an educational toy billed as a " computer" designed and marketed by Edmund Berkeley, with Oliver Garfield from 1955 to 1958, but with Garfield continuing without Berkeley through the 1960s. The name stood for "Genius Almost-automatic Computer" but suggests a portmanteau of genius and ENIAC (the first fully electronic general-purpose computer). Operation Basically a rotary switch construction set, the Geniac contained six perforated masonite disks, into the back of which brass jumpers could be inserted. The jumpers made electrical connections between slotted brass bolt heads sitting out from the similarly perforated masonite back panel. To the bolts were attached wires behind the panel. The circuit comprised a battery, such wires from it to, and between, switch positions, wires from the switches to indicator flashlight bulbs set along the panel's middle, and return wires to the battery to complete the circuit. With this basic setup Geniac could use combinational logic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edmund Berkeley
Edmund Callis Berkeley (February 22, 1909 – March 7, 1988) was an American computer scientist who co-founded the Association for Computing Machinery (ACM) in 1947. His 1949 book ''Giant Brains, or Machines That Think'' popularized cognitive images of early computers. He was also a social activist who worked to achieve conditions that might minimize the threat of nuclear war. Biography Berkeley attended St. Bernard's School and Phillips Exeter Academy. He received a BA in Mathematics and Logic from Harvard in 1930. He pursued a career as an insurance actuary at Prudential Insurance from 1934–48, except for service in the United States Navy during World War II. Berkeley saw George Stibitz's calculator at Bell Laboratories in 1939, and the Harvard Mark I in 1942. In November, 1946 he drafted a specification for "Sequence Controlled Calculators for the Prudential", which led to signing a contract with the Eckert-Mauchly Computer Corporation in 1947 for one of the firs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
State (computer Science)
In information technology and computer science, a system is described as stateful if it is designed to remember preceding events or user interactions; the remembered information is called the state of the system. The set of states a system can occupy is known as its state space. In a discrete system, the state space is countable and often finite. The system's internal behaviour or interaction with its environment consists of separately occurring individual actions or events, such as accepting input or producing output, that may or may not cause the system to change its state. Examples of such systems are digital logic circuits and components, automata and formal language, computer programs, and computers. The output of a digital circuit or deterministic computer program at any time is completely determined by its current inputs and its state. Digital logic circuit state Digital logic circuits can be divided into two types: combinational logic, whose output signals are dependen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Computers
A mechanical computer is a computer 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, the Ascota 170 accounting machine 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WDR Paper Computer
The WDR paper computer or Know-how Computer is an educational model of a computer consisting only of a pen, a sheet of paper, and individual matches in the most simple case. This allows anyone interested to learn how to program without having an electronic computer at their disposal. The paper computer was created in the early 1980s when computer access was not yet widespread in Germany, to allow people to familiarize themselves with basic computer operation and assembly-like programming languages. It was distributed in over copies and at its time belonged to the computers with the widest circulation. The Know-how Computer was developed by and Ulrich Rohde and was first presented in the television program WDR Computerclub in 1983. It was also published in German computer magazines mc and . The original printed version of the paper computer has up to 21 lines of code on the left and eight registers on the right, which are represented as boxes that contain as many matches as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digi-Comp II
The Digi-Comp II was a toy computer invented by John "Jack" Thomas Godfrey (1924–2009) in 1965 and manufactured by E.S.R., Inc. in the late 1960s that used marbles rolling down a ramp to perform basic calculations. A two-level masonite platform with blue plastic guides served as the medium for a supply of marbles that rolled down an inclined plane moving plastic cams as they went. The red plastic cams played the part of flip-flops in an electronic computer - as a marble passed one of the cams, it would flip the cam around - in one position, the cam would allow the marble to pass in one direction, in the other position, it would cause the marble to drop through a hole and roll to the bottom of the ramp. The Digi-Comp II platform measures . The Digi-Comp II was not programmable, unlike the Digi-Comp I, an earlier offering in the E.S.R. product line that used an assortment of plastic slides, tubes, and bent metal wires to solve simple logic problems. Computational power Compu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digi-Comp I
The Digi-Comp I was a functioning, mechanical digital computer sold in kit form. It was originally manufactured from polystyrene parts by E.S.R., Inc. starting in 1963 and sold as an educational toy for US$4.99. A successor, the Digi-Comp II, was not programmable, but in effect a visible calculator. A two-level masonite platform with guides served as the medium for a supply of marbles that rolled down an inclined plane, moving plastic cams as they fell. Operation In essence, the Digi-Comp I contained three mechanical flip-flops, providing an ability to connect them together in a programmable way using thin vertical wires that are either pushed, or blocked from moving, by a number of cylindrical pegs. The whole arrangement was 'clocked' by moving a lever back and forth. Different configurations of these cylinders caused the Digi-Comp to compute different boolean logic operations. With a three binary digit (3-bit) readout of the state of the flip-flops, it could be programmed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slide Rule
The slide rule is a mechanical analog computer which is used primarily for multiplication and division, and for functions such as exponents, roots, logarithms, and trigonometry. It is not typically designed for addition or subtraction, which is usually performed using other methods. Maximum accuracy for standard linear slide rules is about three decimal significant digits, while scientific notation is used to keep track of the order of magnitude of results. Slide rules exist in a diverse range of styles and generally appear in a linear, circular or cylindrical form, with slide rule scales inscribed with standardized Graduation (instrument), graduated markings. Slide rules manufactured for specialized fields such as aviation or finance typically feature additional scales that aid in specialized calculations particular to those fields. The slide rule is closely related to nomograms used for application-specific computations. Though similar in name and appearance to a standard ruler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otis King's Patent Calculator
Otis Carter Formby King (1876–1944) was an electrical engineer in London who invented and produced a cylindrical slide rule with helical scales, primarily for business uses initially. The product was named Otis King's Patent Calculator, and was manufactured and sold by Carbic Ltd. in London from about 1922 to about 1972. With a log-scale decade length of 66 inches, the Otis King calculator should be about a full digit more accurate than a 6-inch pocket slide rule. But due to inaccuracies in tic-mark placement, some portions of its scales will read off by more than they should. For example, a reading of 4.630 might represent an answer of 4.632, or almost one part in 2000 error, when it should be accurate to one part in 6000 (66"/6000 = 0.011" estimated interpolation accuracy). The Geniac brand cylindrical slide rule sold by Oliver Garfield Company in New York was initially a relabelled Otis King; Garfield later made his own, probably unauthorized version of the Otis King ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Science Fiction
''Galaxy Science Fiction'' was an American digest-size science fiction magazine, published in Boston from 1950 to 1980. It was founded by a French-Italian company, World Editions, which was looking to break into the American market. World Editions hired as editor H. L. Gold, who rapidly made ''Galaxy'' the leading science fiction magazine of its time, focusing on stories about social issues rather than technology. Gold published many notable stories during his tenure, including Ray Bradbury's "The Fireman", later expanded as ''Fahrenheit 451''; Robert A. Heinlein's ''The Puppet Masters''; and Alfred Bester's ''The Demolished Man''. In 1952, the magazine was acquired by Robert Guinn, its printer. By the late 1950s, Frederik Pohl was helping Gold with most aspects of the magazine's production. When Gold's health worsened, Pohl took over as editor, starting officially at the end of 1961, though he had been doing the majority of the production work for some time. Under Pohl ''Gala ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Symbolic Analysis Of Relay And Switching Circuits
"A Symbolic Analysis of Relay and Switching Circuits" is the title of a master's thesis written by computer science pioneer Claude E. Shannon while attending the Massachusetts Institute of Technology (MIT) in 1937. In his thesis, Shannon, a dual degree graduate of the University of Michigan, proved that Boolean algebra could be used to simplify the arrangement of the relays that were the building blocks of the electromechanical automatic telephone exchanges of the day. Shannon went on to prove that it should also be possible to use arrangements of relays to solve Boolean algebra problems. The utilization of the binary properties of electrical switches to perform logic functions is the basic concept that underlies all electronic digital computer designs. Shannon's thesis became the foundation of practical digital circuit design when it became widely known among the electrical engineering community during and after World War II. At the time, the methods employed to design logi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Claude Shannon
Claude Elwood Shannon (April 30, 1916 – February 24, 2001) was an American people, American mathematician, electrical engineering, electrical engineer, and cryptography, cryptographer known as a "father of information theory". As a 21-year-old master's degree student at the Massachusetts Institute of Technology (MIT), he wrote A Symbolic Analysis of Relay and Switching Circuits, his thesis demonstrating that electrical applications of Boolean algebra could construct any logical numerical relationship. Shannon contributed to the field of cryptanalysis for national defense of the United States during World War II, including his fundamental work on codebreaking and secure telecommunications. Biography Childhood The Shannon family lived in Gaylord, Michigan, and Claude was born in a hospital in nearby Petoskey, Michigan, Petoskey. His father, Claude Sr. (1862–1934), was a businessman and for a while, a judge of probate in Gaylord. His mother, Mabel Wolf Shannon (1890–1945), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boolean Algebra (logic)
In mathematics and mathematical logic, Boolean algebra is a branch of algebra. It differs from elementary algebra in two ways. First, the values of the variable (mathematics), variables are the truth values ''true'' and ''false'', usually denoted 1 and 0, whereas in elementary algebra the values of the variables are numbers. Second, Boolean algebra uses Logical connective, logical operators such as Logical conjunction, conjunction (''and'') denoted as ∧, Logical disjunction, disjunction (''or'') denoted as ∨, and the negation (''not'') denoted as ¬. Elementary algebra, on the other hand, uses arithmetic operators such as addition, multiplication, subtraction and division. So Boolean algebra is a formal way of describing logical operations, in the same way that elementary algebra describes numerical operations. Boolean algebra was introduced by George Boole in his first book ''The Mathematical Analysis of Logic'' (1847), and set forth more fully in his ''The Laws of Thought, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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