Classification of computers

 CLASSIFICATION OF COMPUTERS 

 Basically computers can be categorized under the following classifications 

1. Classification by Capacity/Size.
2. Classification by function .
3. Classification by power.
4. Classification by purpose 

Classification by Capacity/Size.

Under this we look at the physical size of a computer (its Volume) and the number of people a computer can accommodate at a time, under this category we have the folowing

1.  Main frame computers 
2. Mini computers 
3. Micro computers 
4. Super computers 

Main frame computers 

1. They were the earliest computers which were around upto 1960's. 
2. They were very large almost to fill a room 
3. They were water or air cooled computers
4.  They were very expensive 
5. It could accommodate up to 1000 users at ago 

Mini computers example Notebook PC

1. They are small versions of main frame 
2. They are less powerful in operation than main frame computers 
3. They have fewer processors and they can support up to l00 users at ago. 
4. They can be used in Banking, Education and Industrial areas 
5. They have the same basic structures as the larger main frame computers 
6. Mini computers are heavily used as network servers in the business industry 

Super computers

 1. These are very powerful micro computers 

2. They are computers with a high mathematical capabilities, 

3. These computers are used primarily for research purposes, oil exploration, weather forecasting    

4. They are large computers with faster processing using multiprocessors and superior technology.

Micro computers example Desktop Computers, laptops,video game console etc

1. These are small computers which support only one user at a time 
2. They are mainly used in homes and can commonly referred to as personal computers (PC)
3. Examples of micro computers are Tower PC, Desk Top computers, Laptops, Notebooks and personal digital assistants or palm tops.

Classification by Functions 

Function here refers to how computers are designed to operate, this method of classification give three major categories of computers i.e. 

Digital, analog and hybrid 

Digital computers 

These are computers which carry out there operation in distinct steps using digits. These computers deal with data represented as a series of zero's and ones .They perform there opertion by noting the presence or absence of physical signal in a particular position: This On or off condition represents binary data that can be manipulated arithmetically or logically to produce a solution. Digital computers are used primarily for administrative data processing and mathematical computation and the most commonly used computers.

 Analog computers: 

These are computers which operate by measurement and they use continuous values as opposed to discrete values. 

They are sensitive to the environment, and they measure physical quantities such as temperature, pressure, length, weight, voltage, speed, humidity e.tc, 

They are special-purpose computers designed to solve scientific or technical applications and are quite rare in commercial fields 

Analog computers perform tasks by measuring continuous physical variable (e.g Pressure, length and voltage), manipulating those physical variables to obtain a solution in transforming the solution into numerical equivalent examples are: 

Thermometer, Car speedometer and barometer.

 Analog computers are mainly used for scientific and engineering purposes 

Hybrid computers

These are computers which combine the feature of digital and analog .a hybrid computer is a combination of analog and digital computers liked together by an interface system for converting analog data to digital data and vice versa, they are used in scientific research and other specialized application

Classification by Purpose

 Here computers are classified according to what they were designed to do, some computers are designed to perform a specific task (Special Purpose computers), while others are designed to perform a number of tasks (general purpose computers) 

Special Purpose computers 

These are computers which were designed to carry out a specific purpose or for a particular specific purpose. Such computers might be found in a scientific laboratory where they perform complicated mathematical operations. 

Examples include missiles, building lifts and aero plane simulators. Although usually highly efficient and much faster than general purpose computers, they perform only limited number of functions compared to general purpose computers. 

General purpose computers 

These are computers which were designed to perform wide variety of operations using wide programming languages, such computers could be found in Universities where many different types of programs are written for a variety of purposes, such as research by professors, class assignment by students and registration by staff. 

Classification by Processing power 

In this case computers are classified according to the processor's power and PC clock speed. Examples include: 386 processor running at less than 33mghz speed, 486 processor with speed ranging between 33mhz to 66 MHz , Pentium 1, Pentium l1, Pentium iii. Pentium iv the speed ranges between 77mghz to 2.5GHZ and above.