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

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

Ans. First Generation Computers (1949-55)

The first generation computers used thermionic values (vacuum tubes) and machine language was used for giving instructions. The first generation computers used the concept of ‘stored program’. The computers of their generation were very large in size and their programming was a difficult task.


The first generation computers suffered from some ‘big’ limitations like slow operating speed, restricted computing capacity, high power consumption, short mean time between failures, very large space requirement and limited programming capabilities.

Further researches in this line aimed at removal of these limitations.


Second Generation Computers (1956-65)

A big revolution in electronics took place with the invention of transistors. Transistors were highly reliable compared to tubes. They occupied less space and required only 1/10 of the power required by tubes. Also they took 1/10 time (switching from 1 to 1 or 1 to 0 ) needed by tubes and were ten times cheaper than those using tubes.


Another major event during this period was the invention of magnetic core for storage. Magnetic cores were used to construct large random access memories. These new developments made these computers much more reliable and paved the way for the development of high level language (HLL).


With speedy CPUs and the advent of magnetic tape and disk storage, operating systems came into being.


Third Generation Computers (1966-75)

The third generation’s computers replaced transistors with ‘Integrated Circuits’ known popularly as chips.

The third generation computers using integrated circuits proved to be highly reliable, relatively inexpensive, and faster. Less human labor was required at assembly stage.


Fourth Generation Computers (1976-present)

The advent of the microprocessor chip marked the beginning of the fourth generation computers. The emergence of the microprocessor (CPU on a single chip) led to the emergence of extremely powerful personal computers. Computers costs came down rapidly. The faster accessing and processing speeds and increased memory capacity helped in development of much more powerful operating systems.

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?