" Generation" means to talk about the step in development of technology. It provides a Framework for the growth of computer industry. Originally, the term " generation" was used to distinguish between varying hardware technologies. But it has now been extended to include both hardware and soft ware that made up a computer system.
First generation 1942-1955
1. they were the fastest calculating devices of their time.
2. They use machine language for programming.
3. They were too bulky in size, requiring large rooms for installation.
4. Each vacuum tube used filament, they had a limited life. Because a computer used thousands of vacuum tubes, these computers were prone to frequent hardware failures.
5. Since these computers were difficult to program and use, they had limited commercial use.
6.They used thousands of vacuum tubes that emitted large amount of heat and burnt out frequently. Hence, the rooms/ areas in which these computers were located had to be properly air-conditioned.
Second Generation 1955-1964
characteristics of second generation computers are as follows :
1. They use assembly language for programming.
2.They were almost ten times faster than the first generation computers.
3.They consumed less power and dissipated less heat than the first generation computers. The rooms /areas in which the second generation computers were located still required to be properly air conditioned.
4. They were more reliable and less prone to hardware failures than the first generation computers.
5.In these computers, thousands of individual transistors had to be assembled manually by hand into electronic circuits making commercial production of these computers difficult and costly.
The number of "Transistor" in SSI, MSI, LSI, VLSI technologies are as follows
Third generation 1964-1975
Third generation computers use integrated circuit IC as their CPU component. Integrated circuits are circuits consisting of several electronic components like transistors, resistors, and capacitors grown on a single chip of silicon elimination wired interconnection between components.
This technology was named Small Scale Integration SSI. later with the advancement in technology for manufacturing ICs, it become possible to integrate up to about hundred components on a single chip. This technology came to be known as Medium Scale Integration MSI.
Characteristics of third generation computers are following
1. They were more powerful than second-generation computers. They were capable of performing about 1 million instructions per second.
2. They consumed less power and dissipated less heat than second generation computers. The rooms /areas in which third generation computers were located still required to be properly air conditioned.
3. They were more reliable and less prone to hardware failure than second generation computers requiring lower maintenance cost.
4. They had faster and larger primary and secondary storage as compared to second generation computers.
5.They were general purpose machines suitable for both scientific and commercial applications.
6. they used high level programming language for programming.
7. Timesharing operating system allowed interactive usage and simultaneous use of these systems by multiple user.
8. Timesharing operating system helped in improving the productivity of programmers by saving the time and cost of programming development.
9. Timesharing operation system also made on line systems feasible resulting in usage of these systems for new on-line applications.
Fourth generation 1975-1989
The fourth generation computers were employed during 1975-1989. The invention of Large Scale Integration LI technology and Very Large Scale Integration VLSI technology led to the development of fourth generation computers. However, these computers still used the IC technology to build the basic circuits. The LSI technology allowed thousands of transistors to be fitted onto one small silicon chip.
The progress in LSI and VLSI technologies led to the development of microprocessor, which become the major characteristic feature of the fourth generation computer computers. A microprocessor incorporates various components of a computer-such as CPU, memory and Input/output controls-onto a single chip. The computers in this generation were designed to have a microprocessor, some additional storage chips and support circuitry.
Fourth generation also includes the following developments:
1. Development of graphical user interfaces.
2. Development of new operating systems.
3. Invention of various secondary storage and I/O devices.
4. Development of Local Area Network.
Some of the advantages of fourth generation computers are as follows.
1. The use of LI, VLSI and semiconductor technology made these computers very powerful in terms of their processing speed and access time.
2. They provided a user-friendly environment while working because of the development of GUIs and interactive I/O devices.
Some of the problems associated with fourth generation computers are as following
1. The soldering of LSI and VLSI chips on the wiring board was not an easy task and required complicated technologies to bind these chips on the wiring board.
2. The working of these computers is still dependent on the instructions given by the programmer.
Fifth generation 1989- present
1. Development of various portable computers such as laptop, pocket computer, personal digital assistant PDA, etc.
2. Development of parallel processors.
3. Development of centralized computers called servers.
4. Invention of optical disk technology.
5. Invention of the internet and its different services.
Some of the advantages of fifth generation computers are as follows.
1. They are the fastest and powerful computers till date.
2. They are able to execute a large number of application at the same time and that too at a very high speed.
3. They are versatile for communications and resource sharing.
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