Three Types of computers
Computers can also be divided into three categories, depending on their construction and functions. These are:
- Analog computer
2. Digital computer
3. Hybrid computer
Analog computers
The world analog means continuously varying in quantity the analog computers accept input data in continuous from and output is obtained in the form of graphs. It means that these computers accept input and give output in the form of analog signals. The output is measured on a scale. The voltage current, sound, speed, temperature, pressure etc. values are examples of analog data. These values continuously increase and decrease. The analog computers are used to measure the continuous values.
The analog computers are usually built for special purposes. They have very high speed computing elements used to process physics quantities. The analog computers have low memory size and have fewer functions .these are very fast in processing but output return is not reliable
Early special purpose analog computer devices were the slide Rule, the curvimeter and the harmonic analyser .In world war 2 , analog computer mechanism was of great importance for gunfire control on warships.
The analog computer is used in industrial units to control various processes. They are also used in different fialds of engineering and medicine. The general-purpose analog computer was manufactured in 1930s.
Examples of Analog Devices
Thermometer; it is used to measure the temperature.
Analog Clock; it measure the time by means of the distance continuously covered by the needle around a dial.
Voltmeter; it is used to measure the Voltage.
Speedometer and tire-pressure the gauge; are also example of analog devises.
Characteristics of analog computer
The important characteristics of analog computer are as follows:
- The speed of analog computer is fast as computer to digital computer.
- These computers have no state.
- These computers have limited memory.
- The result of these computers is not reliable as compare to digital computer.
- These computers become the base for digital computer.
Digital Computer
The word ‘’DIGITAL’’ means discrete. It refers to binary system. Which consists of only two digits, i.e 0 and 1, Digital data consists of binary data represented by OFF (low) and ON (high) electrical pulses. These pulses are increased and decreased in discontinuous form rather than in continuous form. In digital computer, quantities are counted rather than measured. A digital computer represents the data in digital signals 0 and 1 and then processes it using arithmetic and logical operations.
Digital computers are used in every field of life. Today most of the computers used in business, educational institutions, hospitals, offices and at homes are digital computers.
Examples of digital computers are IMB PC, COMPAQ, HP, and Apple Macintosh. Similarly, calculators, digital watches and digital thermometers etc. are examples of digital devices.
Features of Digital Computer:
The main features of digital computers are as follows:
Give accurate result
Having high speed of data processing
Can store large amount of data
Easy to program and are general purpose in use.
Consume low energy.
Hybrid Computers:
The hybrid computers have best combined features of both analog and digital computers. These computers contain both the digital and analog components. In hybrid computers, the users can process both the continuous and discrete data. These are special purpose computers. These are very fast and accurate. These are used in scientific fields, in hospitals; these are used to watch patient’s health condition in ICU (intensive care unit). These are also used in telemetry.
Examples of hybrid Devices:
ECG machine and other devices used in ICU.
Device used in petrol pump.
Characteristics of hybrid Computers:
The important characteristics of hybrid computers are as follows:
These are very fast computers.
They are most reliable and provide accurate results.
They are most reliable and provide accurate results.
They can provide output both in numeric and in graphic form.
Both analog and digital components are present in these computers.
