History of Computer

 Computer Image From Past
The history of computers starts out about 2000 years ago.A number of early cultures have developed mechanical computing devices.The abacus probably existed in Babylonia about 3000 B.C. The Chinese abacus is an excellent remaining unsurpassed in speed and accuracy of operation well into this century.
The classical abacus was called "suan pan" by the Chinese- which meant “counting” or “reckoning” board.
The ancient Greeks developed some very sophisticated analog machines. In 1901, an ancient
Greek shipwreck was discovered off the island of Antikythera.
The Romans used their hands to calculate. Because of their extremely cumbersome system of
numbers, they evolved very elaborate “finger” arithmetic

Arabic numbering system that came originally from India had a big advantage over Roman
numerals because of its concept of place value. One column stands for the ones, the next
column for tens, next for hundreds, and so on.
As mathematicians expanded the boundaries of geometry, algebra and number theories, the
outcry for help became greater and greater.
The first to really achieve any success with mechanical calculating machine was Wilhelm
Schickard (1592-1635), a graduate of the University of Tübingen. In 1641 the French mathematician and philosopher Blaise Pascal (1623-1662) built a mechanical adding machine “arithmetic”, a brass box the size of a loaf of bread, with eight dials on its face, that one operated by using stylus to input numbers.Similar work was done by Gottfried Wilhelm Leibniz (1646-1716). The abacus, Pascal’s “arithmetique”, Leibniz’s Wheel- they all required an operator who did each step in sequence. Joseph-Marie Jacquard (1752-1834) invented a loom that could automate textile manufacturing and weave complicated patterns described by holes in punched cards. Charles Babbage (1791-1871) worked on two mechanical devices: the Difference Engine and the far more ambitious Analytical Engine.
One of Babbage's friends, matematician Ada Augusta Byron, Countess of Lovelace (1815-1852), sometimes called the "first programmer" has written on Babbage's machine. The programming language Ada was named for her. William Stanley Jevons (1835-1882), a British economist and logician, built a machine in
1869 to solve logic problems. Herman Hollerith (1860-1929) invented the modern punched card for use in a machine he designed to help tabulate the American 1890 census.In 1928, the German mathematician David Hilbert (1862-1943) addressed the International
Congress of Mathematicians. He posed among others following three fundamental questions:
• Is mathematics complete; i.e. can every mathematical statement be either proved or
disproved?
• Is mathematics consistent, that is, is it true that statements such as "0 = 1" cannot be
proved by valid methods?
• Is mathematics decidable, that is, is there a mechanical method that can be applied to any
mathematical assertion and (at least in principle) will eventually tell whether that assertion
is true or not? This last question was called the Entscheidungsproblem.
In 1931, Kurt Gödel (1906-1978) answered two of Hilbert's questions. He showed that every
sufficiently powerful formal system is either inconsistent or incomplete..
In 1936, Alan Turing (1912-1954) provided a solution to Hilbert's Entscheidungsproblem by
conceiving a formal model of a computer - the Turing machine - and showing that there were
problems that a machine could not solve. One such problem is the so-called "halting
problem": given a program, does it halt on all inputs? At Harvard, Howard H. Aiken (1900-1973) built the Mark I electromechanical computer in 1944, with the assistance of IBM.
At Iowa State University in 1939, John Vincent Atanasoff (1904-1995) and Clifford Berry
designed and built an electronic computer for solving systems of linear equations, but it never
worked properly.
John William Mauchly (1907-1980) with J. Presper Eckert, Jr. (1919-1995), designed and
built the ENIAC, a general-purpose electronic computer originally intended for artillery
calculations.
In 1944, Mauchly, Eckert, and John von Neumann (1903-1957) were designing a stored-
program electronic computer, the EDVAC.
Maurice Wilkes (b. 1913), working in Cambridge, England, built the EDSAC, a computer
based on the EDVAC. F. C. Williams (b. 1911) and others at Manchester University built the
Manchester Mark I, one version of which was working as early as June 1948. This machine is
sometimes called the first stored-program digital computer.
Grace Murray Hopper (1906-1992) conceived of the idea of a compiler, in 1951. She even
invented the language APT.2
John Backus and others developed the first FORTRAN compiler in April 1957. LISP, a list-processing language for artificial intelligence programming, was invented by John McCarthy about 1958. Alan Perlis, John Backus, Peter Naur and others developed Algol. In hardware, Jack Kilby (Texas Instruments) and Robert Noyce invented the integrated circuit in 1959.
Edsger Dijkstra created an efficient algorithm for shortest paths in graphs as a demonstration
of the ARMAC computer in 1956.
In the 1960's, computer science came into its own as a discipline. Operating systems made major advances. Fred Brooks at IBM designed System/360. Edsger.
The 1960's also saw the rise of automata theory and the theory of formal languages. Big
names here include Noam Chomsky and Michael Rabin. Chomsky later became well-known
for his theory that language is "hard-wired" in human brains.
Proving correctness of programs using formal methods also began to be more important in
this decade. Ted Hoff and Federico Faggin at Intel designed the first microprocessor (computer on a chip)
in 1969-1971.
The first RISC architecture was begun by John Cocke in 1975, at the Thomas J. Watson
Laboratories of IBM. Similar projects started at Berkeley and Stanford around this time.
The 1970's also bring the rise of the supercomputer. Seymour Cray designed the CRAY-1,
which was first shipped in March 1976.
In 1981, the first truly successful portable computer was marketed, the Osborne I. In 1984,
Apple first marketed the Macintosh computer.