The document discusses different types of operating systems. It describes batch processing systems where programs were collected and processed sequentially without user interaction. Multiprogramming systems allowed interleaved execution of multiple programs using scheduling techniques. Time-sharing systems enabled interactive use of the computer by multiple users simultaneously via time-slicing of the CPU. Other operating system types include multiprocessing for multiple CPUs, distributed for networked computers, and online systems for immediate transactions.

1. OperatingSystem 11/09/2009 Operating System

2. ? 11/09/2009 Operating System What is Operating System…?

4. Act as interface b/w User and the Hardware

5. Organized set of programs

6. Controls & manage computer resources(H/W, S/W)

7. Schedules task, manage storage11/09/2009 Operating System What is Operating System…?

8. Application Operating System Keyboard Printer Hardware RAM Drives Monitor Operating System in a Hierarchy 11/09/2009 Operating System

10. Managing the resources.11/09/2009 Operating System Primary objectives of Operating System

11. Characteristics of operating System Is a Program Executes at all time Act as Platform Act as police Provides Services 11/09/2009 Operating System

12. Functions of Operating System Process Management Memory Management File Management Security Command Interpretation Device Management 11/09/2009 Operating System

14. OS manages creation & deletion of processes.

15. Methods for process management are:-

16. Manual loading mechanism

17. Batch processing

18. Multiprogramming

19. Multiprocessing11/09/2009 Operating System Process Management

21. Programs are then punched on punch card.

22. Cards are submitted to computer centre.

23. Cards & data were manually loaded.

24. Result of execution of the job was printed on the punch cards. 11/09/2009 Operating System Process of Management in Early Systems

26. Deals with part of memory in use & the memory part which is not in use

27. Allocates memory to processes & de-allocate when they are done 11/09/2009 Operating System Memory Management

29. Manages file stored on the disk.

30. Provides functions to delete, copy, move, rename and view files.

31. Backup of files on stable(non volatile) storage.

32. File access methods :-

33. Sequential Access Files

34. Random Access Files11/09/2009 Operating System File Management

36. Types of Security:-

37. External Security

38. Adequate back-up data

39. Excess of sensitive information only

40. Internal Security

41. User authentication

42. Access control11/09/2009 Operating System Security

44. Accepts input from the user and give corresponding output.

45. Consist of policies and procedures for handling I/O devices.11/09/2009 Operating System Device Management

47. Understands & executes commands entered by human beings.11/09/2009 Command Interpretation Operating System Operating System

48. Batch processing Multi-tasking Types of Operating System Multi-programming Time-sharing Multi- processor Distributed OS Network OS On-line & Real time OS 11/09/2009 Operating System

50. Programs are prepared Offline.

51. Groups of programs are collected together & are processed one by one.

52. Advantage:-Reduces computer idle time.

53. Disadvantage:- Large turn around time.11/09/2009 Operating System Batch processing

55. Operator periodically collect the submitted programs and would batch them together.

56. Batched programs were loaded into input device.

57. Operator gives command to start executing the jobs.

58. Jobs automatically loads from the input device.

59. After process, operator separates and keep the printed output.11/09/2009 Operating System Steps in Batch Processing

61. How does the system know which complier or what hardware devices are to be used by a particular job when there is no operator interventions ?

62. Ans:- Control Statements and Job Control Statement(JCLs)11/09/2009 Operating System Some questions…….?

64. Control cards are indentified by a special character or pattern on the card.

65. JCL tells the OS things such as :-

66. the name of the job

67. the user’s name

68. the I/O devices used during processing.

69. the complier or the assembler to be used.11/09/2009 Operating System Job Control Statements

70. 11/09/2009 Operating System Uniprogramming System Main Memory Operating System OS area User Job User Program area Execution in progress CPU A Uniprogramming system model in which only one job is processed by the system at a time and all the system resources are exclusively available for the job until it completes.

72. One or more programs are executed at the same time.

73. Different scheduling techniques are:-

74. First come first serve

75. Round robin (RR)

76. Shortest job first (SJF)11/09/2009 Operating System Multiprogramming System

77. 11/09/2009 Operating System Multiprogramming System Main Memory Operating System Writing O/P data Job A Secondary Disk Storage Job B Job C (Writing for CPU) CPU Execution in Progress

78. 11/09/2009 Operating System Multiprogramming System Job is allocated the CPU for execution Ready Running New Job Job processing completed I/O completed Job must wait for I/O completion Blocked Three different stages of Job

80. Same as multiprogramming.

81. Multitasking is referred in context to single user.11/09/2009 Operating System Multitasking System

83. Two or more CPU is present.

84. Simultaneously execute several programs.11/09/2009 Operating System Multiprocessing System I/O Units I/O Units I/O Processor CPU Architecture of a computer system showing its CPU, memory & I/O processors

86. Tightly coupled systems

87. Loosely coupled systems.11/09/2009 Operating System Multiprocessing System CPU -1 Main memory CPU-2 I/O processors I/O processors I/O Units I/O Units Basic Org. of a physical multiprocessing System.

89. There are many terminals connected to the same computer.

90. CPU scheduling algorithm is used.

91. Concept of Time Slice is used.11/09/2009 Operating System Time Sharing System

92. 11/09/2009 Operating System Time Sharing System Job is allocated the CPU for execution Ready Running New Job Job processing completed Allocated time slice is over I/O completed Job must wait for I/O completion Blocked The process state diagram for a time-sharing system

94. Airline reservation, Railway reservation, & banking are some of the examples.

95. These OS cannot be modified as it support single application.11/09/2009 Operating System Online Operating System

96. Thanks for your keen interest... 11/09/2009 Operating System