What is Generation of Computer ?

• What is Generation of Computer ?

The history of the pc (Personal Computer)   goes back several decades however and there are 5 definable generations of computers.

Each generation is defined by a big technological development that changes fundamentally how computers operate – resulting in more compact, less costly , but more powerful, efficient and robust machines.

It used to be quite popular to refer to computers as belonging to one of several “Generations” of Computer.

These  Generation are –

UNIVAC

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    1.    The First Generation (1940-1956) –  

   The First Generation 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 and in addition to using a great deal of electricity, generated a lot of heat, which was often the cause of malfunctions. The UNIVAC and ENIAC computers are examples of First Generation Computing devices. The UNIVAC was the first Commercial computer delivered to a business client, the U.S Census Bureau in 1951.

     2.    The Second Generation (1956-1963) –

   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.

      3.    The Third Generation (1964-1971) –  

   The development of the IC or  integrated circuit was the hallmark of the third generation of computers. Transistors were miniaturizes and placed on silicon chips, called semiconductors, which drastically increase 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.

     4.    The Fourth Generation (1971 – 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. The Intel 4004 chip, developed in 1971, located all the components of the Computer ---From the central processing unit and memory to input/output controls --- on a single chip. In 1981 IBM (International Business Machine) introduced its first Computer for the home user, and in 1984 Apple introduced the Macintosh. Fourth generation Computers also saw the development of GUIs (Graphical User Interface), the mouse and handheld devices.

     5.    The Fifth 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. Quantum computation and molecular and nanotechnology will radically change the face of computers in years to come. The goal of fifth generation computing is to develop devices that respond to natural language input and are capable of learning and self-organization.

   What is Vacuum Tube ?

Introduction

The main feature of the Vacuum tube of computer is that the use of the electron tube because the basic electronic component, which is large in size, large in power consumption, short in life, low in reliability and high in cost, and therefore the internal memory uses a mercury circuit . During this era , there was no system software, programmed in machine language and programming language . Computers can only be utilized in a couple of cutting-edge areas, generally for scientific, military, and financial calculations.

Vacuum Tube

A Vacuum tube (also called a VT, Electron tube ) may be a device sometimes wont to amplify electronic signals. In most applications, the Vacuum tube is obsolete, having been replaced decades ago by the bipolar transistor and, more recently, by the FET (field Effect Transistor) . However, tubes are still utilized in some high-power amplifiers, especially at microwave radio frequencies and in some hi-fi audio systems.

Tubes operate at higher voltages than transistors. A typical transistorized amplifier needs 6 to 12 volts to function; the same tube type amplifier needs 200 to 400 volts. At the very best power levels, some tube circuits have power supplies delivering several kilovolts.

Vacuum tubes are making a comeback among audiophiles who insist that tubes deliver better audio quality than transistors. These old-fashioned components are more electrically rugged than their solid-state counterparts; a tube can often withstand temporary overload conditions and power-line transients that might instantly destroy a transistor.

The major disadvantages of tubes include the very fact that they require bulky power supplies, and therefore the high voltages can present an electrical shock hazard.

    What is Transistor ?

Transistor, semiconductor unit for amplifying, controlling, and generating electrical signals. Transistors are the active components of integrated circuits, or “microchips,” which frequently contain billions of those minuscule devices etched into their shiny surfaces. Deeply embedded in almost everything electronic, transistors became the nerve cells of the knowledge Age.

There are typically three electrical leads during a transistor, called the emitter, the collector, and therefore the base—or, in modern switching applications, the source, the drain, and therefore the gate. An electrical signal applied to the bottom (or gate) influences the semiconductor material’s ability to conduct electrical current, which flows between the emitter (or source) and collector (or drain) in most applications. A voltage source like A battery drives the present , while the speed of current flow through the transistor at any given moment is governed by an input at the gate—much as a faucet valve is employed to manage the flow of water through a hose .

The first commercial applications for transistors were for hearing aids and “pocket” radios during the 1950s. With their small size and low power consumption, transistors were desirable substitutes for the vacuum tubes (known as “valves” in Great Britain) then wont to amplify weak electrical signals and produce audible sounds. Transistors also began to exchange vacuum tubes within the oscillator circuits wont to generate radio signals, especially after specialized structures were developed to handle the upper frequencies and power levels involved. Low-frequency, high-power applications, like power-supply inverters that convert AC (AC) into DC (DC), have also been transistorized. Some power transistors can now handle currents of many amperes at electric potentials over thousand volts.

By far the foremost common application of transistors today is for memory chips—including solid-state multimedia storage devices for electronic games, cameras, and MP3 players—and microprocessors, where many components are embedded during a single microcircuit . Here the voltage applied to the gate electrode, generally a couple of volts or less, determines whether current can be due the transistor’s source to its drain. during this case the transistor operates as a switch: if a current flows, the circuit involved is on, and if not, it is off. These two distinct states, the sole possibilities in such a circuit, correspond respectively to the binary 1s and 0s employed in digital computers. Similar applications of transistors occur within the complex switching circuits used throughout modern telecommunications systems. The potential switching speeds of those transistors now are many gigahertz, or quite 100 billion on-and-off cycles per second.