The document summarizes the five generations of computers from the 1940s to present. The first generation used vacuum tubes, the second used transistors, the third used integrated circuits, the fourth used microprocessors and personal computers, and the fifth generation uses ultra-large scale integration chips, larger storage, and internet connectivity. Each generation saw improvements in size, cost, reliability, speed, and commercial availability of computing.

4. Highly unreliable

5. Limited commercial use

6. Difficult commercial Production

7. Costly

9. Mode of germanium semiconductor

10. Highly reliable as compared to tubes

11. Could switch ten times faster than tubes

12. One-tenth the power consumed by tube

13. Smaller than a tube

14. Less expensive to produce

15. Dissipated less heat as compared to vacuum

16. Magnetic cores were used for main memory

19. Smaller in size

20. Consumed less power and dissipated less heat

21. More reliable and less prone to hardware failure

22. Easier to program than previous generation systems

24. Integrating about 10-20 components named as Small Scale Integration (SSI).

25. Later, Technology enhanced to integrate about 100 components on a single chip, known as Medium Scale Integration (MSI).

26. Larger magnetic core memory

27. Larger capacity magnetic disks & tapes as secondary storage

29. Standardization of high level languages (Fortran & COBOL).

31. Smaller in size than second generation

32. Consumed less power & dissipated less heat

33. More reliable & less prone to hardware failures & requiring lower maintenance cost

34. Cheaper to produce commercially

36. A Microprocessor contains all circuits needed to perform arithmetic logic & control functions on a single chip

37. Semiconductor memory

38. Larger capacity hard disks as in-built secondary storage

39. Magnetic tapes & floppy disks as portable storage media

40. Personal computer

42. Graphical user Interface (GUI) provides icons and menus to make it user friendly

43. PC based applications like powerful word processing package, spread sheet package, etc.

44. Multiple windows on a single screen

45. UNIX OS

47. Small, affordable, reliable, easy to use PCs

48. More powerful Mainframe systems

49. They were general purpose machines

50. Easier to produce commercially

51. Groupware is such application that allows multiple members working on a single project located at distant locations using network

53. Larger capacity main memory

54. Larger capacity hard disks

55. Optical disks as portable read only storage media

56. Notebook Computers

57. Powerful desktop PCs & workstations

58. Very powerful mainframe

60. Multimedia applications

62. More powerful, cheaper, reliable

63. Easier to use desktop machines

64. Very powerful mainframes

65. Very high uptime due to hot pluggable components

66. General purpose machines

67. Easier to produce commerciallyExample<br />IBM, Notebooks, Pentium PCs, SUN Workstations, IBM SP/2, PARAM 10000<br />