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Computer classification and generations


Date Posted: 3/18/2017 11:29:21 PM

Posted By: Abced  Membership Level: Gold  Total Points: 1085

Computer classification and generations

A computer can be defined as any electronic device that gets and accepts data,stores it and processes the data in to meaningful information understandable by the user.With the definition in mind,we can list examples of computers like watches,calculators, television sets,thermometers,laptops and mobile phones to be true.All of them get data and manipulate it into necessary information. You can agree with me that there is no device called by name as computer.Computer is just a generic term comprising of many devices.Other than calling a machine in an office as computer,we can call them as desktops,laptops, etc.Therefore we should know that it is so wrong to call desktops as just computer,even a calculator is a computer and it has never been called computer as a name.Let's learn to call devices by specific names but not generic names.Computers can broadly be categorized according to age,size, purpose or functionality, and processing.

According to age,computers are grouped in terms of generations. They include;1st generation computers,2nd generation computers,3rd generation computers,4th generation computers, and finally 5th generation computers.

1st generation computers.This is a generation of computers that were discovered between the years 1946 and 1957.These computers had the following characteristics: They used vacuum tubes for circuiting.They used magnetic drums as memory for data processing.Their operating system was quite low as compared to the later generations.An operating system can be defined as a collection of programs designed to control the computer's interaction and communication with the user. A computer must load the operating system like Microsoft into memory before it can load an application program like Ms Word.These computers required large space for installation.They were large in size and could take up the entire room.They consumed a lot of power.They also produced huge amounts of energy and power which saw machines breaking down oftenly. Using the

computers,programming capabilities was quite low since the computers relied on machine language.Machine language can only be understood by the computer but not human beings .Their input was based on punched cards and paper tapes.

2nd generation computers. These computers existed between the years 1958 and 1964.They possessed the following features:These computers used transistors for circuitry purposes.They were quite smaller in size compared to the 1st generation computers. Unlike the 1st generation computers, they consumed less power. Their operating system was faster.During this generation, programming languages such as COBOL and FORTRAN were developed.This phase of computers relied on punched cards too for input and printouts.

3rd generation computers.These are computers that existed between 1965 and 1971.The computers used integrated circuits(ICs) for circuitry purposes.The computers were smaller in size due to the introduction of the chip.They had a large memory for processing data. Their processing speed was much higher.The technology used in these computers was small scale integration (SSI) technology.

4th generation computers. The computers under this generation were discovered from 1972 to 1990s. The computers employed large scale integration (LSI) technology.The size of memory was /is high/large,hence faster processing of data.Their processing speed was high.The computers were also smaller in size and less costly in terms of installation.This phase of computers saw introduction of keyboards that could interface well with processing system.During this phase, there was rapid internet evolution.Other advances that were made included the introduction of GUI(graphical user interface) and mouses.Other than GUI, there exist other user interfaces like natural-language interface,question-and-answer interface,command line interface(CLI) and form-fill interfaces.

5th generation computers.These are computers that are still under development and invention. There development might have began in 1990s and continues in to the future. These computers use very large scale integration (VLSI) technology. The memory speed of these computers is extremely high.The computers can perform parallel processing. It is during this generation that Artificial Intelligence (AI) concept was generated e.g voice and speech recognition. These computers will use quantum computation and molecular technology.They will be able to interpret data and respond to it without direct control by human beings.

According to power and size,computers are divided into the following;Microcomputers, minicomputers, supercomputers, mainframe computers and mobile computers.
Microcomputers.They are smaller and cheaper compared to mainframe and supercomputers They are also less powerful. E.g Personal computers (PCs) and desktop computers.
Minicomputers.These are mid sized computers that are less expensive compared to mainframe computers and super computers. E.g IBM midrange computers.
Mainframe computers. These are very large expensive computer systems.They are faster in processing data but less expensive compared to supercomputers.
Supercomputers. Faster computers that were very expensive and required a lot of mathematical calculations.They are used to process very large amounts of data.
Mobile computers. These computers are further classified into notebooks and laptops-midsized computers placed at your lap/thigh while operating, palmtops-smaller devices that can be held by hand/palms(mobile phones and calculators), and personal digital assistants (PDAs).

According to purpose or functionality, computers are classified as general purpose and special purpose computers. General purpose computers solve large variety of problems.They are said to be multi purpose for they perform a wide range of tasks. Examples of general purpose computer include desktop and laptops.
On the other hand,special purpose computers solve only specific problems.They are dedicated to perform only particular tasks.Examples of special purpose computers can include calculators and money counting machine.

According to processing, computers are divided into digital,analog and hybrid computers. Digital computers process data represented in the form of discrete values.These are actually binary values represented as 0s and 1s,where 1 means true while 0 means false. Data is represented in form of square waves.Such devices are very accurate since values are displayed on the machine's screen,only the required value is displayed.Examples of such devices include digital watches and calculators. Analog computers process data represented by physical variables and output physical magnitudes in the form of smooth curves,or rather sine or cosine waves.Data is represented as continuous values,though not always accurate since the pointers to values may not be straight to point accurately at the correct value. Examples of such devices include analog clocks and thermometers.
Hybrid computers combine the properties of both analog and digital computers.Hybrid computers compute large amounts of data represented in form of complex equations.Such machines can be found in hospitals for measuring patients heartbeats.

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