COMPUTER IS A VERY COMMON ELECTRONIC DEVICE IN THE PRESENT WORLD. THE GROWTH OF COMPUTERS HAPPENED THROUGH DIFFERENT STAGES. JUST LIKE FIRST GENERATION,SECOND GENERATION,THIRD GENERATION,FOURTH GENERATION...
IN THIS ARTICLE WE DISCUSSING ABOUT DEVELOPMENT OF COMPUTERS.
The word ‘computer’ is an old word that has changed its meaning several times in the last few centuries. Originating from the Latin, by the mid-17th century it meant ‘someone who computes’. The American Heritage Dictionary (1980) gives its first computer definition as “a person who computes.” The computer remained associated with human activity until about the middle of the 20th century when it became applied to “a programmable electronic device that can store, retrieve, and process data” as Webster’s Dictionary (1980) defines it. Today, the word computer refers to computing devices, whether or not they are electronic, programmable, or capable of ‘storing and retrieving’ data. The Techencyclopedia (2003) defines computer as “a general purpos
The Tech-encyclopedia (2003) defines computer as “a general purpose machine that processes data according to a set of instructions that are stored internally either temporarily or permanently.” The computer and all equipment attached to it are called hardware. The instructions that tell it what to do are called "software" or “program”.
the evolution of computer is defining through following steps...
The Mechanical Era (1623-1945)
In 17th century machines were used to solve mathematical problems. this was a basic for development of computers. Wilhelm Schickhard, Blaise Pascal, and Gottfried Leibnitz were among mathematicians who designed and implemented calculators that were capable of addition, subtraction, multiplication, and division included The first multi-purpose or programmable computing device was probably Charles Babbage's Difference Engine, which was begun in 1823 but never completed. In 1842, Babbage designed a more ambitious machine, called the Analytical Engine but unfortunately it also was only partially completed. Babbage, together with Ada Lovelace recognized several important programming techniques, including conditional branches, iterative loops and index variables.
First Generation Electronic Computers (1937-1953)
in first generation computers vacuum tubes were used instead of electronic relays. this was a result of many effort taken by scientists. The earliest attempt to build an electronic computer was by J. V. Atanasoff, a professor of physics and mathematics at Iowa State in 1937. Atanasoff set out to build a machine that would help his graduate students solve systems of partial differential equations. By 1941 he and graduate student Clifford Berry had succeeded in building a machine that could solve 29 simultaneous equations with 29 unknowns. However, the machine was not programmable, and was more of an electronic calculator. The first general purpose programmable electronic computer was the Electronic Numerical Integrator and Computer (ENIAC), built by J. Presper Eckert and John V. Mauchly at the University of Pennsylvania. Research work began in 1943, funded by the Army Ordinance Department, which needed a way to compute ballistics during World War II. The machine was completed in 1945 and it was used extensively for calculations during the design of the hydrogen bomb. Eckert, Mauchly, and John von Neumann, a consultant to the ENIAC project, began work on a new machine before ENIAC was finished.
second generation computers have very importance in the development of modern computers. this generation computers changed a lot of factors, this used circuit system for computers. Electronic switches in this era were based on discrete diode and transistor technology with a switching time of approximately 0.3 microseconds. The first machines to be built with this technology include TRADIC at Bell Laboratories in 1954 and TX-0 at MIT's Lincoln Laboratory. Index registers were designed for controlling loops and floating point units for calculations based on real numbers.
Third Generation (1963-1972)
Technology changes in this generation include the use of integrated circuits, or ICs (semiconductor devices with several transistors built into one physical component), semiconductor memories, microprogramming as a technique for efficiently designing complex processors and the introduction of operating systems and time-sharing. The first ICs were based on small-scale integration (SSI) circuits, which had around 10 devices per circuit (or ‘chip’), and evolved to the use of medium-scale integrated (MSI) circuits, which had up to 100 devices per chip. Multilayered printed circuits were developed and core memory was replaced by faster, solid state memories.
in fourth generation computers chips are used in a large volume. Whole processors could now fit onto a single chip, and for simple systems the entire computer (processor, main memory, and I/O controllers) could fit on one chip. Gate delays dropped to about 1ns per gate. Core memories were replaced by semiconductor memories. Large main memories like CRAY 2 began to replace the older high speed vector processors, such as the CRAY 1, CRAY X-MP and CYBER.
This generation brought about the introduction of machines with hundreds of processors that could all be working on different parts of a single program. The scale of integration in semiconductors continued at a great pace and by 1990 it was possible to build chips with a million components - and semiconductor memories became standard on all computers. Computer networks and single-user workstations also became popular.
this is the last generation computers that invented. Most of the developments in computer systems since 1990 have not been fundamental changes but have been gradual improvements over established systems. This generation brought about gains in parallel computing in both the hardware and in improved understanding of how to develop algorithms to exploit parallel architectures.
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