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Computer generations are the advancement of computer technologies over years. There are basically five generations of computers. Namely;

  1. First Generation
  2. Second Generation
  3. Third Generation
  4. Fourth Generation
  5. Fifth generation

Computer Generations Time Used Component Used
First Generation 1946-1959 Vacuum tubes
Second Generation 1959 - 1965 Transistors
Third Generation 1965 - 1971 Integrated Circuits (IC)
Fourth Generation 1971 - 1980 Processor
Very Large Scale Integrated Circuits (VLSI)
Fifth Generation 1980 – till today Ultra Scale Integrated Circuits (ULSI)
Micro Processor (SILICON CHIP)
(Artificial Intelligence)


    First Generation : 1946-1959 (Vacuum tubes)
  1. The first computers used vacuum tubes for circuitry and magnetic drums for memory.
  2. They were often enormous and taking up entire room.
  3. First generation computers relied on machine language.
  4. They were very expensive to operate and uses a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions.
  5. The UNIVAC and ENIAC computers are examples of first-generation computing devices.
    1. Characteristics of First Generation:
    2. Large room sized computers
    3. Used thousands of vacuum tubes for internal operations
    4. Consumed a lot of power
    5. Generated a lot of heat
    6. Had many wires
    7. Low speed
    8. Used punched cards for input and output
    9. Introduction of machine language
    10. Computers were too expensive.
      1. Examples of First Generation
      2. Mark; 1944 (Automatic Sequence Controlled Calculator)
      3. Atansoff Berry Computer (ABC)
      4. Electronic Numeric Integrator and Calculator (ENIC); (1946)
      5. Electronic Discrete Automatic Computer (EDAC); (1946)
      6. Universal Automatic Computer (UNIVAC)

    Second Generation : 1959 - 1965 (Transistors)
  1. Transistors replaced vacuum tubes and ushered (put the mark) in the second generation of computers.
  2. High-level programming languages were also being developed at this generation, such as early versions of COBOL and FORTRAN.
  3. These were also the first computers that stored their instructions in their memory.
  4. Unlike the first generation computers, these used transistors for internal operations and typically contained 10,000 transistors connected by wires and they were reliable.
    1. Characteristics of Second Generation:
    2. Introduction of high level programming language like COBOL
    3. Computers become less expensive
    4. Computers gave off less heat
    5. Small in size
    6. Processing speed increased and became more reliable.
      1. Examples of Second Generation
      2. Livermore Automatic Research Computer (LARC)
      3. Tele-Star Computer; - for American airline

    Third Generation : 1965 - 1971 (Integrated Circuits (IC's)
  1. The development of the integrated circuit (IC) was the hallmark of the third generation of computers.
  2. Transistors were miniaturized and placed on siliconchips, called semiconductors.
  3. Instead of punched cards and printouts, users interacted with third generation computers through keyboards and monitors and interfaced with an operating system.
  4. Allowed the device to run many different applications at one time.
  5. In this generation, Integrated Circuits were usable.
    1. Characteristics of Third Generation:
    2. Introduction of integrated circuits semiconductors devices with several transistors built into one physical component.
    3. Introduction of operating system example Multics
    4. Low cost of computer
    5. Highly reliable and small in size
    6. Consumed less heat
      1. Examples of Third Generation
      2. IBM 360 - 1964
      3. DEC-PDP-8 mini computers - 1965

    Fourth Generation : 1971 - 1980 (Processor)
  1. The microprocessor brought the fourth generation of computers, as thousands of integrated circuits were built onto a single silicon chip.
  2. The Intel 4004 chip, developed in 1971, located all the components of the computer.
  3. From the central processing unit (CPU) and memory to input/output controls—on a single chip.
  4. Fourth generation computers also saw the development of Graphical User Interface (GUI), the mouse and handheld devices.
  5. These are computers in use today which contain more sophisticated microelectronic devices such as complex IC's or large scale integrated circuits.
    1. Characteristics of Fourth Generation:
    2. Development of the microprocessor
    3. Computers are more powerful
    4. Cheap enough for purchase
      1. Examples of Fourth Generation:
      2. Micro-computers IBM - 1979
      3. PC-1981
      4. Laptop-1988

    Fifth generation : 1980 - onwards (Artificial Intelligence)
  1. Fifth generation computing devices, based on artificial intelligence (AI).
  2. AI is the simulation of human intelligence processes by computer systems. These processes include learning reasoning and self-correction.
  3. AI include expert systems, speech recognition and machine vision.
  4. Are still in the development process, though there are some applications, such as voice and face recognition.
  5. The goal of fifth-generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.
  6. There are many predictions that in a few years to come, computers that will be able to converse with people in human like manner and will be able to mimique human senses, manual skills and intelligence. Artificial intelligence methods give computers the capability to make decisions based on evidence of the past rather than on a set of programmed procedures.
  7. Thus, thinking like human beings.
    1. Characteristics of Fifth generation:
    2. Artificial intelligence
    3. Mimique human senses

Read also Computer Evolution