Friday, September 30, 2011

Generations of Computers



Computer’s history is classified into 5 generations
       1st Generation
        2nd Generation
        3rd Generation
        4th Generation
        5th Generation

1st Generation

From 1940 to 1956

  •             The first computers used
  •             vacuum tubes for circuitry and
  •             magnetic drums for memory, and were
  •             often enormous, taking up entire rooms.

  •             They were very expensive to operate.

  •             They  using a great deal of electricity, and

  •             generated a lot of heat, which was often the cause of malfunction.

First generation computers relied on machine language, the lowest-level programming language understood by computers, to perform operations, and they could only solve one problem at a time. Input was based on punched cards and paper tape, and output was displayed on printouts.

2nd Generation
From 1956 to 1963

    •             Transistors replaced vacuum tubes and ushered in the second generation of     computers.

    •             The transistor was invented in 1947 but did not see widespread use in computers           until the late 1950s.

    •             The transistor was far superior to the vacuum tube, allowing computers to become         smaller, faster, cheaper, more energy-efficient and more reliable than their first-  generation predecessors.

Though the transistor still generated a great deal of heat that subjected the computer to damage, it was a vast improvement over the vacuum tube. Second-generation computers still relied on punched cards for input and printouts for output.


                                                               3rd Generation
From 1964 to 1971

  •             The development of the integrated circuit was the hallmark of the third generation  of computers.

  •             Transistors were miniaturized and placed on silicon chips, called semiconductors, which drastically increased the speed and efficiency of computers.

    • Instead of punched cards and printouts, users interacted with third generation  computers through keyboards and monitors and interfaced with an operating  system, which allowed the device to run many different applications at one time with a central program that monitored the memory.

·        Computers for the first time became accessible to a mass audience because they were smaller and cheaper than their predecessors.

4th Generation
From 1971 to Present

  •             The microprocessor brought the fourth generation of computers, as thousands of            integrated circuits were built onto a single silicon chip.

What in the first generation filled an entire room could now fit in the palm of the hand.

    •  In 1981 IBM introduced its first computer for the home user, and in 1984 Apple introduced the Macintosh.

  •             Microprocessors also moved out of the realm of desktop computers and into many        areas of life as more and more everyday products began to use microprocessors.

    •  As these small computers became more powerful, they could be linked together to form networks, which eventually led to the development of the Internet.

    •  Fourth generation computers also saw the development of GUIs, the mouse and handheld devices.

5th Generation





Present and Beyond

Fifth generation computing devices, based on artificial intelligence, are still in             development, though there are some applications, such as voice recognition, that are being used today
    • The use of parallel processing and superconductors is helping to make artificial intelligence a reality.
    •  The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.