On the basis of Working Principle

CLASSIFICATIONOF COMPUTERON THEBASIS OFWORKINGPRINCIPLE

Computer is more and more common in the world today. In less than 100 years, computers have revolutionized much of human society. The many ways in which people communicate, create, work and play continue to be influenced and possibly even enhanced by modern computers. Considering how common computers have become, there are different types of a computer for various of different necessities.

The computers on the basis of application/working principle are:

• Analog computer
• Digital computer
• Hybrid computer

Analog Computer

Analog computer is one which operates on continuous data, usually of a physical nature such as length, voltage or current, etc. An analog machine is usually a special purpose device dedicated to a single task. Analog computers are based on analog signals that are continuous signals.

These types of computers were widely used in scientific and industrial applications. These are used in a hospital to measure the size of the stone in kidney and mental diseases diagnostics.

Analog computer works by measuring rather than counting. It is usually used for scientific work rather than personal purpose and commercial use so it is special purpose computer. It is powerful in solving differential equations.

Comparing to the digital computer, it has less storage capacity and less accuracy performance. It is specially designed to perform continuous physical force like computing the temperature, pressure and other. It represents physical quantities in the form of waves or in continuous form.

Presley, thermometer , speedometer, barometer, lactometer, etc are the example of an analog computer. An example of analog devices is a thermometer, barometer, speedometer and ammeter.

Characteristics of analog computer

• The speed of an analog computer is fast but have no state.
• These computers work with physical values such as temperature, pressure etc.
• These computersare based on continuous data.
• These computers are not reliable and are difficult to use and operate.
• These computers are the base for digital computers.
• These computers have small memory.
• No possibility of reprogramming.
• Normally, an analog computer cannot be reprogrammed.

Digital Computer

The computer which works on discrete data or discontinuous data is known as a digital computer. It works on a binary system where 0 represent off and 1 represents on. It is based on digital signals i.e discrete signals.

So, the basic principle of these computers are either present or absence of an electric pulse in the signals. It is a multipurpose and programmable computer. It is fast processing, more accurate and has large memory capacity. It is usually general purpose computer. Some examples of a digital computer are IBM PC, Apple/Macintosh computer, etc.

Characteristics of digital computer are:

• Digital computer operates by calculation.
• It is multipurpose computer and can be reprogrammed.
• It has large storage capacity than an analog computer.
• The results are accurate and high.
• It stores the data in the form of a bit.
• The processing speed is very fast.
• These machines are automatic.
• These computers are versatile in a sense that they can carry out different types of a job at a time without any interference.
• A computer works with same speed,same accuracy, and with the same efficiency at all time.

The differences between analog and digital technologies :are

Hybrid Computer

A computer, which has a combination best feature of both analog and digital computers is called a hybrid computer. It helps the user to process discrete and continuous data. The hybrid computer can convert the analog signal into digital signals and digital signal into analog signal. Hybrid computers are used mainly in specialized applications where both kinds of data need to be processed. Therefore, they help the user to process both continuous and discrete data.

They have usually the speed of digital computers and the accuracy of analogcomputers. They can perform the task of both analog and digitalcomputer.They are usually used for special problems, as it is a special purpose computer in which input data are derived and measurement are converted into digits and processed by a computer.

The practically they are used in the field of the following places:

• During rocket launching process, where the analog components/ devices measure the speed of the rocket, temperature and pressure of the atmosphere, then, these measurements are converted into digital signals and supplied to the digital devices to analyze the data for taking appropriate steps on launching.

• In hospitals, analog components measure the temperature and blood pressure of a patient, then, these measurements are converted into a digital signal and fed to the digital devices that monitor patient's vital information.

• In weather forecasting, analog devices measure wind speed, humidity, temperature, wind direction and fed to the digital devices that compare with the past information to predict the climate changes.

• In automated industry, analog component measure temperature, pressure, speed and provide it to digital component that takes proper action.

CHARACTERISTICSOF HYBRIDCOMPUTER

• It is the combination of qualities of analog as well as a digital computer.
• It can process both continuous and discrete data.
• It is special purpose computer.
• It can convert one type of data into another.
• It is mostly used in radar communication, rocket launching, weather forecasting and in other fields.
• It usually high cost compared to analog and digital computer.
• Hybrid Machines are generally used in scientific applications or in controlling industrial processes.

(Dilli , 2015)

Bibliography

Dilli , S. P., Singh, k. E., Khadka , D., Bhatta, K. D., Baral, N., Saud, R. S., . . . Dangi, R. (2015). Fundamental of Computer Science. Kathmandu: KEC publication and Distribution.

Singh,Bikash Kumar et.al.Computer Science-XI,Aathari Publication Pvt.Ltd,ktm