Digital, Analog and Hybrid Computers

Q35. How are digital, analog and hybrid computers different from one another?

Ans. Digital Computer

The digital computers work upon discontinuous data. They convert the data into digits (binary digits 0 and 1) and all operations are carried out on these digits at extremely fast rates. A digital computer basically knows how to count the digits and add the digits. Digital Computers are much faster than analog computers and far more accurate. Computers used for business and scientific applications are digital computers.


Analog Computer

In analog computers, continuous quantities are used. Computations are carried out with physical quantities such as voltage, length, current, temperature etc. the devices that measure such quantities are analog devices, for example voltmeter, ammeter. Analog computers operate by measuring rather than counting. The main advantage of analog computers is that all calculations take place in parallel and hence these are faster. But their accuracy is poor as compared to digital counterparts. Analog computers are mostly used in engineering and scientific applications. An electronic weighing scale is an example of an analog computer.


Hybrid Computer

Hybrid computers utilize the best qualities of both the digital and analog computers. In these computers some calculations take place in analog manner and rest of them take place in digital manner. Hybrid computers are best used in hospital where analog part is responsible for measurement of patient’s heart beat, blood pressure, temperature and other vital signs and then the operation is carried out in digital fashion to monitor patient’s vital sign. Hybrid computers are also used in weather forecasting.


Computer Overview – Short Question Answers

Q1. What is a computer?

Q2. Define and distinguish between data and information.

Q3. Briefly explain the significance of Input-Process-Output Cycle.

Q4. Briefly explain the basic architecture of a computer.

Q5. What do you understand by input unit? What is its significance? What does computer input consist of?

Q6. What is the function of CPU in a computer system? What are its subunits?

Q7. What functions are performed by the control unit? Can we call it the control centre of computer system? Why?

Q8. What functions are performed by the ALU? Is it an independent unit? If not, which unit does ALU work in coordination with?

Q9. Distinguish between Input unit and Output unit.

Q10. Distinguish between CPU and ALU.

Q11. What is the function of output unit in a computer system? Give example of some output devices.

Q12. What role does memory play in the functioning of computer system?

Q13. What is a bit? What is binary code?

Q14. Define each of the following:

(a) nibble

(b) byte

(c) kilobyte

(d) megabyte

(e) gigabyte

(f) terabyte.

Q15. What is the meaning of the term volatile primary memory? What can be done to overcome the problems of volatility?

Q16. Distinguish between internal and external memory.

Q17. Draw a block diagram of the main units of a computer hardware system.

Q18. What are the differences between hardware, software and firmware?

Q19. What are the software classifications? Discuss their functioning in brief.

Q20. What is the binary system used in the computers?

Q21. What is the difference between system software and application software?

Q22. How are human compared with respect to speed and capacity of information processing?

Q23. What are the advantages and disadvantages of using computers?

Q24. Explain briefly the major innovations of

(i) first generation computers,

(ii) second generation computers,

(iii) third generation computers,

(iv) fourth generation computers?

Q25. What is the Von Neumann architecture? Did it influence the making of computers? How?

Q26. Describe the stored-program concept and explain how it changed computer processing.

Q27. How are the computers of four different generations superior as compared to their previous models?

Q28. How are computers classified? How are they different from one another?

Q29. How is the microcomputer different from the other computers?

Q30. What are the four different types of computers based on their working methods?

Q31. Identify and discuss characteristics and uses of

(a) Minicomputers

(b) Mainframe computers, and

(c) Supercomputers.

Q32. Compare microcomputers with minicomputers and mainframe in terms of size, cost and capabilities.

Q33. List at least three advantages of computer data processing over manual methods.

Q34. What do you understand by the term ‘Super Computers’? Give the name of a supercomputer installed in India.

Q35. How are digital, analog and hybrid computers different from one another?