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History of IT

History of IT. Four basic periods:. Premechanical era around 3000 B.C. – 1450 A.D. inventions of: - writing and alphabets - pens and papers - books and libraries - numbering systems, first calculator. The Abacus. 2. Mechanical age lasted from 1450 to 1850

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History of IT

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  1. History of IT

  2. Four basic periods: • Premechanical era • around 3000 B.C. – 1450 A.D. • inventions of: • - writing and alphabets • - pens and papers • - books and libraries • - numbering systems, first calculator The Abacus

  3. 2. Mechanical age • lasted from 1450 to 1850 • W. Shickard invented a computing machine (+, -) • B. Pascal’s Pascaline (mechanical addition, subtraction of numbers) • 1673 – Leibniz’s machine ( +, -, *, / ) • Ch. Babbage: - the difference engine • - the analytical engine (punch cards) • J. M. Jacqard invented a loom that used the punch cards The pascaline Difference and analytic engines

  4. 3. Electromechanical age • lasted from 1840 to 1940 • beginnings of telecommunication: • - telegraph (early 1800s), Morse code (1835, S. Morse), telephone (1876, A. G. Bell), radio (1894, G. Marconi) • Herman Hollerith: - census machine (punch cards) • - established the IBM • MARK 1: -completed in 1942, an automatic-sequence calculator • - 3 calculations/sec, worked for 15 years • - 8 feet tall, 51 feet long, 2 feet thick, weighed 5 tons

  5. 4. Electronic age • 1945 – ENIAC: - Electronic Numerical Integrator and Computer • - 1st fully electronic computer, used vacuum tubes • - couldn’t store its programs • - developers: John Mauchly, J. Prosper Eckert • - funded by U.S. Army, used for military purposes • John von Neuman: binary system (0,1) • stored-program computers: Manchester Mark 1, EDSAC, EDVAC • the first general-purpose computer for commercial use: • UNIVAC (universal automatic computer)

  6. Four generations of digital computing 1.- vacuum tubes=main logic elements - used punch cards and rotating magnetic drums 2. - transistors as main logic element - magnetic tape and discsinstead of punched cards, magnetic cores for internal storage of data 3. - intgrated circuits - MOS memory replaced the magnetic cores - development of operating systems and programming languages 4. – large-scale and very large-scale integrated circuits - microprocessors, containing memory, logic, control circuits (CPU=central processing unit) - this allowed the home-use of PCs

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