Friday, June 11, 2010

CLASSIFICATION OF COMPUTER

CLASSIFICATION OF COMPUTER
Based on generation
Based on type
Based on purpose
Based on size and processing power

BASED ON GENERATION
This refers to the periods and stages of development of computer. This stages or period of development started from 1946 to date.

REASONS FOR GENERATION OF COMPUTER
Capability: Need for more powerful, reliable computer since the first generation may not be able to carryout some certain jobs.
Cost: The cost of purchasing which is high. E.g. vacuum tube is exorbitant such that only the well-to-do (rich) could own a computer.
Power consumption: Old generation of computer consumes so much electricity; hence there is need for machine that can carryout the same jobs but consumes less electric current.
Size: Need for computer which can perform same task but smaller in size so that computer can be owned by private individual and small business.
Speed: Need for computer of higher speed to make our work faster and easier.
Cost of production: Since the cost of producing computer is less, the cost of producing old generation computer can be used to produce more micro computer.
Production of heat: need for computer that perform the same function but produces less heat.

FIRST GENERATION OF COMPUTER
This generation of computer proceeds from the year 1946 – 1960 and it uses vacuum tube as a means of its storage. Examples of machines used under the first generation of computer are: EDSAC (Electronic Delay Storage Automatic Computer), UNIVAC (Universal Automatic Computer), and ENIAC (Electronic Integrator and Computer)

FEATURES OF FIRST GENERATION COMPUTER
a. They are very large computers
b. They generate a lot of heat
c. They consume a lot of power
d. They are very expensive

SECOND GENERATION OF COMPUTER
This generation of computer proceeds from the year 1960 – 1964 and it uses transistors as a means of storage. A transistor is a fraction of huge vacuum tube. It is more capable in processing than the vacuum tube. A transistor can perform the work of 1000 vacuum tubes.

MERITS OF TRANSISTORS OVER VACUUM
a. Transistor is a fraction of vacuum tube
b. It is faster than the vacuum tube
c. It is accurate
d. It occupies less space
e. It is more powerful and can perform the work of 1000 vacuum tubes.

THIRD GENERATION OF COMPUTER
This generation of computer proceeds from the year 1965 – 1970 and it was (IC) integrated circuit which replaces transistors. Integrated circuit is the combination of so many transistors. It includes the IBM 360 main frame family. The system was more powerful, reliable and compacted. The integrated circuit can carryout the job of 40 transistors. IC is a fraction of transistors.

FEATURES OF 3RD GENERATION COMPUTERS
a. It is smaller in size than the former generations computers
b. It provides less heat
c. It is very powerful in productivity
d. It cost lesser compare to the former generations of computer

FOURTH GENERATION OF COMPUTER
This generation of computer proceeds from the year 1970 – 1980. Improvement was made on the integrated circuit to the large scale integrated circuit or VASIC chips were computed more fight to create 20,000 circuit or more. They are equipment of several hundred of thousands of transistors and it operates a million times faster than old vacuum tube. The micro computer falls under this generation because of its size, easy to use, low cost of purchase.

FIFTH GENERATION OF COMPUTER
This generation of computer is referred to as future computers. They are proposed to be as intelligent and capable as a human being. These computers will be able to have instructions with human. They will recognize voices and have human senses. They would be self-sufficient to a very large storage capacity from the previous computers. They will unlike the fourth generation store and process knowledge based context data and inference engine.

EXERCISE 1a:
1. What do you understand by the term computer
2. What is Abacus
3. List and explain the possible reasons for the generations of computer
4. Compare and contrast between the Third and Second generations of computer
5. List and explain the various stages computer passed before reaching the present stage.
6. What are the characteristics of the first generation computers

CLASSIFICATION OF COMPUTER BASED ON TYPE
The following are the classification of computer based on type:
Analog computer
Digital computer
Hybrid computer

Analog Computer: This is a type of computer that reads data using measurement and some program scale. It is calculated by measuring continues changes in physical quantities. Examples: car speedometer, wrist watch, thermometer etc.

Digital Computer: This measures physical quantities by counting, which are addition, subtraction, division and multiplication. Examples: electric wrist watch, fuel disposal in petrol fuelling station (nozzle).

Hybrid Computer: These are special computer which performs the operation of both analog and digital computers. It works by measuring and counting respectively. Example: higher computer.
Higher computers: these are special purpose computer that performs both the operation of analog and digital computers which are used for exploitation.

CLASSIFICATION OF COMPUTER BASED ON PURPOSE
Classification of computer based on purpose is divided into two namely:
General purpose computers
Special purpose computers

General Purpose Computer: These are computers that can be used to carryout different jobs and serve variety of problems.

Special Purpose Computer: These are computer that are specially designed for a particular job or task. Example: computer designed for air traffic control etc.

CLASSIFICATION OF COMPUTER BASED ON SIZE AND PROCESSING POWER
The following are the classification of computer based on size and processing power:
a. Super computers
b. Mainframe computers
c. Mini computers
d. Micro computers

Super Computers: These are very large computers that are roomed to all sizes. This type of computer is usually used by big companies.

Mainframe Computers: These are also large in size. Both the super and mainframe computer are high speed computers performing billions of calculations per second and they have storage capacity.

Specialized super computers could be used for designing weapons, weather forecasting, biomedical analysis, research and air craft design. Examples: paragon from inter corp. USA. They have important use in military department in developed countries. Mainframe computers on the other hand can support thousands of users at a time and it is used for data processing in large organization for information and data base management. But they are expensive and they generate a lot of heat.

Mini Computers: These are small version of mainframe computers designed to support more than one user at a time but many take up to (200) users at a time. It is not portable and it is expensive and it generates a lot of heat.

Micro Computers: These are latest technology in computer to reduce the size of computer hence, the development of personal computer (PC3) indicating that an individual can now have computer at home and small offices. They are durable, cheap, fast and generate less heat. The following are the types of micro computers:
Tower computers
Desktop computers
Laptop computer
Notebook computers
Palmtop computers

Tower Computers: These are computers that are positioned vertically on their stand. They are not usually that portable. There are two types of tower computers namely:
Full tower: This type of tower carries or comes along with speakers on the System Unit.
Mini tower: The mini computer does not carry or come along with speakers on the System Unit.

Desktop Computers: These are micro computers that lie horizontally on their stand or on a desk (desktop). In most offices, the desktop computer (CPU) is placed on a desk while the monitor rest on top of it.

Laptop Computers: These are very portable computers designed to be supported on the lap and with varying sophistication. The laptop computers are more portable when compared to the desktop or tower computers.
Notebook Computers: These are very portable computers usually notebook or textbook sizes. The notebook computers are a little smaller than the laptop computers but perform the same type of task.

Palmtop Computers: These are very small computers designed to be operated on the palm like mobile phone, calculator, organizer etc. This type of computer is among the smallest size of computer.

2 comments:

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