Computer and its generation
Introduction
A computer is simply a tool for people to use ; it is a machine that can solve any problem by accepting data , performing certain operations on that data , and presenting results of those operations.
A computer is an information processing machine. It can perform arithmetic operations and the logical decisions . it has a memory and can store lots of information. The stored information may be retrieved , moved and operated upon as desired. Computation are done at an extremely fast speed with complete reliability and accuracy. The speed of execution of operation by modern computer is several million operations per second in comparison to slow computers.
These are basically three types of computers - Analog , digitaldigital and hybrid.
Analog computer
An analog computer accepts , processes and generates continuous data. Computation are carried out with physical quantities , such as length, voltage, current, etc.
Digital computer
A digital computer accepts , processes and produces discrete data. Computation are done with discrete quantities, such as numerical digits. Usual fax machine , electronic calculators are simple examples of digital devices.
Hybrid computer
These computers are combinations of analog and digital computers . Hybrid computers are used in applications where the material to be worked with is analog in nature but the processing must be digital. For example, when a hospital patient is physically attached to the analog section, the digital section can record and print out in numbers, the patient's pulse or temperature.
Computer generation
First generation
Computers designed during the period 1946- 59 are generally termed as the firat generation computers. These include ENIAC, EDSAC , UNIVACI, IBM 650. The computers of this generation used vacuum tubes and were bulky and rather slow. Their memory was limited and they used punched cards and punched paper tape for input and output of data.
Second generation computers
The second generation computers were characterized by their use of tiny transistors. Due to this , these were compact and substantially smaller in size.
They required less power to operate. They were much more reliable as compared to the first generation computers. Second generation computers had more speed , larger memory and faster input output devices. They accepted procedure- oriented languages such as FORTRAN, COBAL and other utility programmes.
The second generation computers, span spreads over the years 1959-65.
Examples of second generation computers are IBM 1401
Third generation computers
The third generation computers ( 1965-70) used integrated circuits instead of transistor. The size of such circuits is hundreds of times smaller than the transistor circuit size. Moreover, the associated, electronic circuitry is also reduced in dimension many many times. Third generation computers are mostly general purpose , that is, they may be used for processing business, scientific or text- oriented problems. Some examples of third generation systems have been IBM 360 series.
Fourth generation computers
The forth generation computers use very large scale integrated circuits in their design. As compared to the third generation systems, these system posses much larger computing power. They have extremely large memories and are very versatile. In addition to conventional input output devices, other mini/ large computers, magnetic ink readers, optical readers , audio response terminal, etc, can be attached to them. Some examples of fourth generation computers are IBM 370, NEC supercomputers and so on.
Fifth generation computers and beyond
The computer technology has made phenomenal progress , starting from first to fourth generation . computers have been used to solve almost any type of problems whose algorithm can be described explicitly. The fifth generation computers incorporate the concept of artificial intelligence and expert system thereby enabling the computers take decision almost like human beings , speech synthesiser as well as the use of video disks and tapes for external storage media.
A computer is simply a tool for people to use ; it is a machine that can solve any problem by accepting data , performing certain operations on that data , and presenting results of those operations.
A computer is an information processing machine. It can perform arithmetic operations and the logical decisions . it has a memory and can store lots of information. The stored information may be retrieved , moved and operated upon as desired. Computation are done at an extremely fast speed with complete reliability and accuracy. The speed of execution of operation by modern computer is several million operations per second in comparison to slow computers.
These are basically three types of computers - Analog , digitaldigital and hybrid.
Analog computer
An analog computer accepts , processes and generates continuous data. Computation are carried out with physical quantities , such as length, voltage, current, etc.
Digital computer
A digital computer accepts , processes and produces discrete data. Computation are done with discrete quantities, such as numerical digits. Usual fax machine , electronic calculators are simple examples of digital devices.
Hybrid computer
These computers are combinations of analog and digital computers . Hybrid computers are used in applications where the material to be worked with is analog in nature but the processing must be digital. For example, when a hospital patient is physically attached to the analog section, the digital section can record and print out in numbers, the patient's pulse or temperature.
Computer generation
First generation
Computers designed during the period 1946- 59 are generally termed as the firat generation computers. These include ENIAC, EDSAC , UNIVACI, IBM 650. The computers of this generation used vacuum tubes and were bulky and rather slow. Their memory was limited and they used punched cards and punched paper tape for input and output of data.
Second generation computers
The second generation computers were characterized by their use of tiny transistors. Due to this , these were compact and substantially smaller in size.
They required less power to operate. They were much more reliable as compared to the first generation computers. Second generation computers had more speed , larger memory and faster input output devices. They accepted procedure- oriented languages such as FORTRAN, COBAL and other utility programmes.
The second generation computers, span spreads over the years 1959-65.
Examples of second generation computers are IBM 1401
Third generation computers
The third generation computers ( 1965-70) used integrated circuits instead of transistor. The size of such circuits is hundreds of times smaller than the transistor circuit size. Moreover, the associated, electronic circuitry is also reduced in dimension many many times. Third generation computers are mostly general purpose , that is, they may be used for processing business, scientific or text- oriented problems. Some examples of third generation systems have been IBM 360 series.
Fourth generation computers
The forth generation computers use very large scale integrated circuits in their design. As compared to the third generation systems, these system posses much larger computing power. They have extremely large memories and are very versatile. In addition to conventional input output devices, other mini/ large computers, magnetic ink readers, optical readers , audio response terminal, etc, can be attached to them. Some examples of fourth generation computers are IBM 370, NEC supercomputers and so on.
Fifth generation computers and beyond
The computer technology has made phenomenal progress , starting from first to fourth generation . computers have been used to solve almost any type of problems whose algorithm can be described explicitly. The fifth generation computers incorporate the concept of artificial intelligence and expert system thereby enabling the computers take decision almost like human beings , speech synthesiser as well as the use of video disks and tapes for external storage media.
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