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INTRODUCTION A COMPUTER is an electronic device that can be instructed to carry out an arbitrary set of arithmetic or logical operations automatically. Characteristics of Computers Speed: The speed of computation is very high as the signals pass at the speed of light. Thus, millions of calculations can be done in a second. Accuracy: As computers work on inbuilt software programs, there is no scope for human errors and are hence, highly accurate. Information and Storage: A computer can store a large amount of data or instructions in its memory which can be retrieved at point of time. Other characteristics include: Consistency, Automatic Operation, and Flexibility. History of Computers Father of Computer: Charles Babbage Father of Modern Computer Science: Alan Tuning First Un-programmable Electronic Digital Computer: Atanas off Berry Computer (ABC) First Purpose Electronic Digital Computer: Electronic Numerical Integrator and Calculator (ENIAC) GENERATIONS OF COMPUTERS: First Generation (1946 - 1959) Used vacuum tubes & batch processing OS Machine & Assembly Languages used Examples: ENIAC, EDVAC, UNIVAC, IBM-701, IBM-650 Second Generation (1959-1965) Used transistors OS: Multi-Bag remaining, Time sharing Memory: Magnetic cores, magnetic tapes and disks Used assembly and high-level languages like FORTRAN, COBOL, Algol Examples: IBM 1620, IBM 7094, CDC 1604 Third Generation (1965-1971) Used ICs OS: Remote processing, Time-sharing, Real-time, Multi-programming Used High-level languages FORTRAN-II TO IV, COBOL, PASCAL PL/1, BASIC, ALGOL-68 Examples: IBM-360 series, Honeywell-6000 series, PDP, IBM-370/1683 Fourth Generation (1971-1980) VLSI Circuits Used Memory: Semiconductor and Winchester disk High level Languages: Fortan 77, Pascal, Cobol used REKIB AFREDI 2 Visit:www.rekibafredi.com
DATA PROCESSING CYCLE OF A COMPUTER A computer's data processing cycle comprises of the following three steps: 1. Input: It refers to the commands given by a user to the computer using input devices like mouse, keyboard etc. 2. Processing: In this step, the command given by the user are carried out by the computer. Thus, this step produces a more useful form of data at the end. 3.Output: The result of the processing that is stored and displayed to the user by means of output devices like monitor, printer etc. is called output. REKIB AFREDI 4 Visit:www.rekibafredi.com