Types of Computers based on Principles of Operation
There are three different types of computers according to the principles of operation. Those three types
of computers are
- Analog Computers
- Digital Computers
- Hybrid Computers
1- Analog Computers:
Analog Computer is a computing device that works on continuous range of values. The analog computers accept input and give output in the form of analog signals. It generally deals with physical variables such as voltage, pressure, temperature, speed, etc.
In World War II, analog computing mechanisms were used for gunfire control on warships.
The general purpose analog computer was first build in 1930.
Examples of Analog Computer:
Early special purpose analog computers were the
- Slide Rule
- the curve meter
- plain meter
- harmonic analyzer
2- Digital Computers:
The digital computer operates on digital data such as numbers. It uses binary number system in which there are only two digits 0 and 1. Each one is called a bit. Digital computer describe everything in one of the two states ON/OFF, TRUE/FALSE, YES/NO, OR 1/0.The digital computer is designed using digital circuits. . Digital computer is well suited for solving complex problems in engineering and technology. Hence digital computers have an increasing use in the field of design, research and data processing.
In early 1940’s, Howard H. Aiken built the first general purpose-purpose digital computer called MARK-I
Examples of Digital computers:
Examples of digital computers are IBM PC, Apple Macintosh Computers etc.
Based on the purpose, Digital computers can be further classified as
- General Purpose Computers
- Special Purpose Computers
Special purpose computer is one that is built for a specific application.
General purpose computers are used for any type of applications.
3- Hybrid Computers (Analog + Digital):
A hybrid computer combines the features of analog and digital computers. It is mostly used for automatic operations of complicated physical processes and machines.
Example:
In hospital’s ICU, analog devices might measure the patient’s temperature, blood pressure and other vital signs.
These measurements which are in analog might then be converted into numbers and supplied to digital components in the system. These components are used to monitor the patient’s vital sign and send signals if any abnormal readings are detected. Hybrid computers are mainly used for specialized tasks.
What is Difference between Analog and Digital Computer?
| Sr. No | Analog Computer | Digital Computers |
| 1 | Accepts the input in analog signals and give result on scale. | Accepts the input in digital form and gives the result in digital form. |
| 2 | It is less accurate and reliable in calculations. | It is more accurate and reliable in calculations. |
| 3 | It has fewer functions | It has many functions. |
| 3 | It is difficult to use | It is easy to use |
| 5 | It has low memory | It has fast memory |
| 6 | It has slow speed | It has fast speed |
| 7 | It is not easily programmable | It is easily programmable |
| 8 | It is only used for special purpose | It is general purpose in use. |
| 9 | It deals with quantity | It deals with numbers. |
| 10 | It has no state | It has states ON or OFF |
| 11 | It is used in engineering and science | it is used in al fields of life |
| 12 | It is costly | It is low in cost. |
Types of Computers based on size and data processing capacity
Classification of Computers:
Computer is classified on the basis of size and data processing capacity. Today’s computers are classified into following categories:
- Super Computers
- Mainframe Computers
- Mini Computers
- Micro Computers
1- Super Computers:
Super computers are the most powerful computers of today. These are the largest, fastest and expensive computers developed in 1980’s to handle complex problem. A supercomputer can have thousands of processors connected parallel. A super computer is also multi user computer and can serve unlimited number of users. It also keeps large storage capacity. CRAYT90, CRAY-XP, Roadrunner, Blue Gene, ETA-10, Deep Blue and ASCI White are examples of super computers.
Uses:
Super computer are normally used large corporation, universities, and government agencies that can afford them
Applications of Super Computers:
- Weather forecasting
- Space Research
- Nuclear Research
- Real-time animations
- Structural Analysis
2- Mainframe Computers:
Mainframe computers are specially design for the heavy intensive workload. It is multiuser system and can serve more than 50000 users simultaneously. It has a capability to store the data of all the users safe and sound. It is connected through the t
erminals or personal computers.
Some examples of mainframe are IBM S/390, NEC 610,DEC-10, ES-9000,IBM system Z10
Terminal: Every Computer that is part of a computer network is called a terminal.
Uses:
Mainframe used in large organizations like banks, airlines and universities where many people need frequently access to the same data, which is usually organized into one or more huge databases.
Applications of Mainframe Computers:
- Banks
- Railway and Airline Reservations
- Universities
- Government agencies like NADRA
3- Minicomputers:
Minicomputer was introduced in 1960’s; it is smaller in size and less powerful than mainframe computer.
minicomputers have less processing power than mainframe computers but have high processing power than microcomputers. Normally, it contains two or more processors in it using the multiprocessor technology. It has large storage capacity and greater efficiency. It is a multiuser system. It is accessed through the personal computer or terminals. It can serve more than 1000 terminals simultaneously. The minicomputer is also called mid-range-server. Some examples of minicomputers are HP 3000, IBM 360, Prime 9755, AS 400, and VAX 8650.
Uses:
The minicomputers are used in office, industry and government departments.
Applications of Minicomputers:
- Business transaction processing and data base management
- Engineering and scientific research
4- Microcomputers:
Microcomputer is the least powerful class of the computer. It is used in our daily small business and home. Only one user can use the microcomputer at a time. IBM introduced its first microcomputer in 1981 called IBM-PC.
The major factor of the popularity of microcomputer is its low price. PCs are becoming powerful day by day because of the improvement in technology. Today, a powerful microcomputer may be used as substitute for mini or mainframe computer.
Uses:
Microcomputers are commonly used in almost every field of life such as at home, small offices, business, education etc.
Application of Microcomputers:
- Word processing
- Image processing
- Entertainment (Watching Movies-Playing Games)
- Education
- Hospitals
- Accounts and financial analysis of small companies
Microcomputers are available in different models. These are:
- Desktop computers
- Laptop Computers
- Pocket or Palmtop Computers
- Desktop Computers:
A desktop computer is designed so that the system unit, input devices, output devices, and any other devices fit entirely on or under a desk or table. In some models, the monitor sits on top of the system unit, which is placed on the desk. The more popular style of system unit is the tall and narrow tower, which can sit on the floor vertically.
Types of Desktop Computers:
There are two types main types desktop computer available. These are:
- Macintosh made by Apple Computers.
- Personal Computer(PC)
Macintosh made by Apple Computers:
Macintosh computers are popular for their stylish look and bright colors. These computers use Macintosh operating system.
Personal Computer (PC).
A personal computer is a computer that can perform all of its input, processing, output, and storage activities by itself. When people talk about PC, they usually mean IBM-compatible computer based in an Intel microprocessor. The most common operating for PC is Microsoft Windows. Some PCs also uses Linux and UNIX operating system.
2- Pocket/Palmtop Computers:
These are the type of computers that can be held in hand every time just like ha pencil or calculator. These computers are very small in size and can be fit in our pocket. This type of computer uses special operating system. A pocket computer ha small rechargeable battery used to operate it. One problem with these computers is that they do not have full-sized keyboard. They use special pens and touch-sensitive screen to enter information as well as a number of small buttons or key.
3- Laptop Computer:
A laptop is a portable personal computer that can be carried anywhere you go. Laptop computers use the same type of operating system and you can run the same software on the laptop computer as you can run on desktop or microcomputers.
Laptop computer is operated on the special rechargeable battery and it does not have to be plugged in like desktop computer. Laptop computer is mostly used in during journey. It can be used on our lap. It is the reason that this type of computer is named as laptop computer.
Modern laptop can have floppy drives, CD-ROM drives and CD-writers and even DVD drives. They also have full-sized keyboard and a mouse or touch- sensitive mouse pad. It uses the LCD(Liquid Crystal Display) screen to display the information.
