Encyclopedia of Computer Science and Technology

530 Appendix IIing company (CTR) in 1911. In 1924, it will become InternationalBusiness Machines (IBM).1904• J. A. Fleming invented the diode vacuum tube. Together withLee de Forest’s invention of the triode two years later, thisdevelopment defined the beginnings of electronics, offering aswitching mechanism much faster than mechanical relays.1919• The “flip-flop” circuit was invented by two American physicists,W. H. Eccles and R. W. Jordan. The ability of the circuitto switch smoothly between two (binary) states wouldform the basis for computer arithmetic logic units.1921• Karl Capek’s play R.U.R. introduced the term robot. Robotswill become a staple of science fiction “pulps” starting in the1930s.1930• Vannevar Bush’s elaborate analog computer, the DifferentialAnalyzer, went into service.1936• Alonzo Church developed the lambda calculus, which canbe used to demonstrate the computability of mathematicalproblems.• Konrad Zuse built his first computer, a mechanical machinebased on the binary system.1937• Alan Turing provided an alternative (an equivalent) demonstrationof computability through his Turing Machine, animaginary computer that can reduce any computable problemto a series of simple operations performed on an endlesstape.• Bell Laboratories mathematician George Stibitz createdthe first circuit that could perform addition by combiningBoolean operators.1938• In a key development in robotics, Doug T. Ross, an Americanengineer, created a robot that can store its experience inmemory and “learn” to navigate a maze.• G. A. Philbrick developed an electronic version of the analogcomputer.• Working in a garage near Stanford University, WilliamHewlett and David Packard began to build audio oscillators.They called their business the Hewlett-Packard Company.Fifty years later, the garage would be preserved as a historicallandmark.1939• John Atanasoff and Clifford Berry built a small electronicbinary computer called the Atanasoff-Berry Computer(ABC). A 1973, court decision would give this machine precedenceover ENIAC as the first electronic digital computer.• George Stibitz built the Complex Number Calculator, whichis controlled by a keyboard and uses relays.1940• Claude Shannon introduced the fundamental concepts ofdata communications theory.• George Stibitz demonstrated remote computing by controllinghis Complex Number Calculator in New York from aTeletype terminal at Dartmouth College in New Hampshire.1941• Working in isolation in wartime Germany, Konrad Zusecompleted the Z3. Although still mechanical rather thanelectronic, the machine used sophisticated floating-pointnumeric data.1943• The British-built Colossus, an electronic (vacuum tube) special-purposecomputer that can rapidly analyze permutationsto crack the German Enigma cipher.1944• Howard Aiken completed the Harvard Mark I, a large programmablecalculator (or computer) using electromechanicalrelays.• John von Neumann and Stanislaw Ulam developed theMonte Carlo method of probabilistic simulation, a toolthat would find widespread use as computer power becomesavailable.1945• Zuse continued computer development and created asophisticated matrix-based programming language calledPlankalkül.• Vannevar Bush envisioned hypertext and knowledge linkingand retrieval in his article “As We May Think.”• Alan Turing developed the concept of using proceduresand functions (subroutines) called with parameters. Histeam also developed the Pilot ACE (Automatic ComputingEngine), which would help the development of a Britishcomputer industry.1946• ENIAC went into service. Developed by J. Presper Eckertand John Mauchly, the machine is widely considered tobe the first large-scale electronic digital computer. It used18,000 vacuum tubes.• In the “Princeton Reports” based upon the ENIAC work, Johnvon Neumann, together with Arthur W. Burks and HermanGoldstine described the fundamental operations of moderncomputers including the stored program concept—the holdingof all program instructions in memory, where they can bereferred to repeatedly and even manipulated like other data.1947• The Association for Computing Machinery (ACM) wasfounded.