Classification of Computer On the Basis of Work

The computer is an electronic device which accepts the input and processes them to give desired output. There are various types of computer available in the market. We can classify the computer as special purpose computers and general purpose computers. Special purpose computers are applicable on particular application area and have limited area for application like temperature recording, speed measurement, telephone billing etc, but general purpose computers are the standard computers used for general application like word processing, spreadsheet, database application, internet access, program development etc.

Analog Computer:

The computer that work with natural phenomena and physical values like earthquake measurement, speed of the wind, weight light etc is known as Analog computers. It is especially used in scientific work, medical and industrial field. These are special purpose computers. It measures physical values such as temperature or pressure that fall along a continuous scale in temperature or pressure. For example, you can see a system on petrol pump that contains an analog processor and analog device that converts flow of petrol into quantity. Speedometer in cars and your watch are other examples of analog computer.

Features of Analog computer

• It is specific to the particular task so we cannot use it for multiple applications.
• It works on continuous data and gives continuous output.
• It works on real time and no storage capacity.
• It gives in the form of a graph, signals, table etc.

Digital Computer:

A computer that work with digital value 0 and 1. Where 0 is OFF and 1 is ON. It works with discrete data. Digital computer does not measure the continuous data for continuous output. Most of the electronic system is based on the digital system. Digital computers are very popular for actual computers are very popular for actual computer works like preparation of the report, documentation, billing and other graphical work etc. The entire PC (Personal Computer) used today on different fields are digital computers.

Features of Digital computer

• It works on the discontinuous or discrete data.
• It is applicable for the general purpose so this is very versatile for the application.
• It is based on the digits 0 and 1.
• It is faster.
• It has storage section also.
• It is highly accurate and reliable than an analog system.

Hybrid computer:

It is the combination of analog and digital computer system. It works with continuous and discrete value. The good qualities of analog and digital computers are combined on this computer and made the hybrid computer. These are used in ICU (Intensive Care Unit) of the hospital, jet planes, and other data analysis terminals. Hybrid computer transfers the data from analog to digital and digital to analog and vice-versa.

Features of hybrid computer

• It is an expensive system.
• It is designed for a special purpose so it is not versatile.
• It works on discrete and continuous value.
• It has limited storage.
• It is complex than other computer systems.

Some useful technical terms

1. The computer which possess continuous data. ( Analog computer)
2. The computers which are used in offices for general purpose. (Personal computer)
3. The fastest and most expensive computer system. (Super computer)
4. The computers that use the microprocessor as their CPU. (Microcomputer)
5. A computer that uses analog and digital device. (Hybrid computer)
6. Picture element on the monitor. (Pixel)
7. The computer that uses discrete on/off system. (Digital computer)
8. The portable computer which can be used where these is on direct electricity. (Laptop computer)
9. The original computers developed by IBM Company. (IBM PC)
10. The device which converts analog signal to digital and vice-versa. (Modem)

Classification of Computer On the Basis of Size

We can classify computers on the basis of size as below:

Super computer

Super computer is the fastest, most expensive, big in size, and most powerful computer that can perform multiple tasks within no second. It has multi-user, multiprocessing, very high efficiency and large amount of storage capacity. It is called super computer because it can solve difficult and complex problem within a nano second.

Application

• Used to forecast the weather and global climates
• Used in military research and defense systems
• In automobile, aircraft, and space craft designing
• Used in seismography, plasma and nuclear research
• Study of genetic engineering
• Digital film recording

Example
C-DAC (Center for Development of Advanced Computer) of India has developed PARAM series of Super Computer. ANURAG is also Indian Super Computer. Other Super Computers are CRAY XMP/14, CDC-205 etc. Mr. Seymour Cray was a pioneer person in the field of supercomputer production. He had developed the first super computer Cray-1 in 1976.

Mainframe Computer

Mainframe Computer is the large sized computer that covers about 1000 sq feet. It is general purpose computer that is designed to process large amount of data with very high speed. It accepts large amount of data from different terminals and multiple users and process them at same time. More than 100 users are allowed to work in this system. It is applicable for large organization with multi-users for example: large business organization, Department of examinations, Industries and defense to process data of complex nature. It uses several CPU for data processing.

Application Areas

• Government and civilian
• Credit card processing
• Back Account management
• Marketing
• Business data processing in large organization
• Air traffic control system
• Industrial design

Example
IBM S/390, IBM S/709, ICL 39, CDC 6600

Minicomputer

Mini Computers are medium sized computer. So, these are popular as middle ranged computer. It is also multiple user computer and supports more than dozen of people at a time. It is costlier than microcomputer.

It is also used in university, middle range business organizations to process complex data. It is also used in scientific research, instrumentation system, engineering analysis, and industrial process monitoring and control etc.

Example
Languages, multimedia, graphics, 3D graphics and games. These are popular among students, professionals and home users due to small size, low price and low maintenance.
PDP-11, VAX etc.

Microcomputer

Most popular general purpose computers which are mostly used on day to day work are microcomputers. These are popular as Home PC or Personal Computer (PC) because these are single user computers and mostly used for personal use and application. These support many higher level application cost and easy in operation.

Example
IBM PCs, Apple Mac, IBM PS/2, All computer available with Pentium Models etc.

Use of Digital Computer in Our Daily Life

There are various types of digital computer used in our practical life. Some of them are described below:

Laptop and Palmtop Computers

These are small sized digital computers so they are called handheld computers. These are portable in size and mobile in nature but are not replacements for desktop computers. Desktop computers continue to perform major processing functions while palmtop are used for access the information and communication. These are less power consuming and equipped with all the facilities of modern PC. These computers can be operated by battery. It has CD drive, floppy drive, modem and other input/output ports.

The idea of laptop computer was originated by Alan Kay of Xerox Palo Alto Research Center in 1979 and named to notebook like computer as Dynabook, but first Laptop was designed in 1979 by William Moggridge of Grid System Crops. In 1983, Gavilan produced a laptop computer with 62 kilobyte memory, MS-DOS operating system, touch pad mouse and portable in size.

Multimedia computer

The term multimedia is not unknown among computer users. Multimedia is a combined form of two or more media like as text, graphics, sound, animation etc. Now a day, the multimedia PC is a choice of all. Analog Digital Converter (ADC) converts the sound wave into digital signal in multimedia computer. Without the talk of MPEG (Motion Picture Expert Group), the multimedia is incomplete. It is a standard used to compress sound (audio) and videos for computer. It is named MPEG-1, MPEG-2 etc.

PDA (Personal Digital Assistants)

Small sized portable hand-held electronic device which has all the features of personal computers called PDA. It has input, processing, storage and output capability like the other microcomputers. This is used for diaries, calendars, address books etc. We can transfer data from PDA to personal computer and personal computer to PDA.

Classification of Computer On the Basis of Brand and Model

On the basis of brand

On the basis of brand, computer has two world wide brands:

IBM PC:

It stands for International Business Machine Personal Computer and developed by IBM Company. It is commonly known as the IBM PC. IBM Company is the first company that manufactured computer. It was founded by a team of engineers and designers. It has given the new technology on the basis of Charles Babbage principal.

Example
Original IBM PC, XT and AT.

IBM compatible:

The term compatible means ‘Able to exist together and successfully’. IBM compatible computer system is assembled form of different components developed by different companies. It is based on IBM principle that can use standard hardware and software designed for the IBM PC and its own additional features.

Example
IBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT.

Apple computer:

Computers developed by Apple Industry are apple computers. This used a standard microprocessor chips. The chip enabled them to put together a complete computer, a keyboard for input, and processors in memory and screen all in small box.

Apple II is known as personal computer. IBM PC and its compatible version have largest scope in PC market. Most of the users of the world have IBM PC than these computers but Apple has its own users, mostly people interested in graphic works, documentation and publishing sectors.

On the Basis of Model

On the basis of Model, computer is classified as:

• XT Computer (Extra Technology): It cannot support GUI based operating system. Its processing speed is 4.77 MHz and Intel 8080, 8086, 8088 series of microprocessors is used.
• AT Computer (Advance Technology): It supports GUI based operating systems. Its speed is 2 GHz and word length 64 bits. Its processors are Intel series of 80286, 80386, Pentium II etc.
• PS/2 Computer: It is a laptop computer which is rechargeable and battery based system. It is operated with OS/2 operating system.