Unit 1 - Operating System Overview - 2 marks solution

1.          What is meant by principle of locality of reference?

Locality of reference can be used to predict what instructions and data a program will use in the near future based on its accesses in the recent past. Locality of references is of two types:

Temporal locality – Programs tend to reuse data and instructions they have used recently in the near future.

Spatial locality – in programs, instructions and related data tends to cluster.

Unit 1 - Operating System Overview - 2 marks solution

1.        List the elements of a computer system.

2.        What are the two modes in which a program can execute? Compare them.

                User mode – Task / process is executed on behalf of user

                Kernel mode – Task / process is executed on behalf of the OS

3.        What is an operating system?

An operating system is a program that manages a computer’s hardware / resources. It provides the interface between the user and the computer hardware. It also controls the execution of application programs and acts as an interface between applications and the computer hardware.

1.        State the functions of an operating system.

2.        What are the main purposes of operating system?

a.    Provide interface between user and computer hardware

b.    Manage all resources of the computer

c.    Support for installing and executing application programs

3.        List the services of operating system.

a.    Program execution

b.    Access to I/O devices

c.    Controlled access to files

d.   System access

e.    Error detection and response

f.    Accounting

4.        What is an instruction execution?

Program consists of a set of instructions stored in memory. Processor executes a program by executing the set of instructions. Instruction execution consists of two steps – FETCH instruction from memory one at a time and EXECUTE. Processing required for a single instruction is called an instruction cycle.

5.        List the categories of Processor action.

1.    Processor-memory: Data transfer from processor to memory or from memory to processor.

2.    Processor-I/O: Data transfer between a peripheral device (I/O module) and the processor.

3.    Data processing: processor performs arithmetic / logic operation on data.

4.    Control: An instruction that may alter the sequence of execution.

23.     List the three types of interface in a computer system.

a.    Instruction Set Architecture (ISA) – set of instructions that a computer can execute

b.    Application binary interface (ABI) – provides binary portability across programs

c.    Application programming interface (API) – specifies a set of functions that are available to an application programmer. They provide support for programs to access the hardware resources and services available in a system through the user Instruction set architecture (ISA) supplemented with high-level language (HLL) library calls.

24.     What is an API? List the common API available for application programmer.

Application Programming Interface (API) specifies a set of functions that are available to an application programmer. They provide support for programs to access the hardware resources and services available in a system through the user Instruction set architecture (ISA) supplemented with high-level language (HLL) library calls. Three of the most common APIs available to application programmers are

a.    Windows API for Windows systems,

b.    POSIX API for POSIX-based systems

c.    Java API for programs that run on the Java virtual machine.

25.     State the advantage of using API over system calls.

a.    Program portability – Programs using Application Programming Interface (API) can be compiled and run on any system that supports the same API. When system calls are used, the programs can be run on systems supporting the same Instruction Set Architecture (ISA) only.

b.    Difficulty – System calls are more detailed and difficult to work with than API

26.     What are the three methods used by programs to pass parameters to OS?

Three general methods are used by programs to pass parameters to the operating system.

1.    Pass the parameters in registers.

2.    Store the parameters in a block, or table, in memory, and the address of the block is passed as a parameter in a register

3.    Programs can push parameters into stack and OS can pop the parameters.

27.     What are system programs?

System Programs are the programs that are required to run the system. They provide a convenient environment for program development and execution. Example – System programs for file management are used to create, delete, copy, rename, print, dump, list, and generally manipulate files and directories.

28.     What are system utilities?

System utilities are application programs that are often supplied along with the operating system to solve common problems, or perform common operations. Programs include web browsers, word processors and text formatters, spreadsheets, database systems, compiler compilers, plotting and statistical-analysis packages, and games.

Unit 1: Operating System Overview

1. List the elements of a computer system.

2. What are the two modes in which a program can execute? Compare them.

3. What is an operating system?

4. State the functions of an operating system.

5. What are the main purposes of operating system?

6. List the services of operating system.

7. What is an instruction execution?

8. List the categories of Processor action.

9. What are privileged instructions?

10. What is an interrupt? List the classes of interrupts.

11. What is an interrupt? State its advantage.

12. What are the approaches taken to handle multiple interrupts?

13. What is a trap?

14. List the types of memory in a computer system.

15. What is a cache memory? State the need for cache memory.

16. What is meant by principle of locality of reference?

17. What is a disk cache?

18. What is DMA?

19. What are the three techniques used for I/O operations?

20. What are system calls?

21. What is the purpose of system calls?

22. How is protection for memory provided by OS?

23. State use of fork and exec system calls.

24. What are the two models of communication in a system?

25. Can system calls be made directly from a high level language program?

26. What is an API? List the common API available for application programmer.

27. List the three types of interface in a computer system.

28. State the advantage of using API over system calls.

29. What are the three methods used by programs to pass parameters to OS?

30. What are system programs?

31. What are system utilities?

32. What is a kernel?

33. What are the main goals of designing an operating system?

34. Draw the UNIX system structure.

35. Draw the system structure of any one operating system.

36. What are the main advantages of the microkernel approach to system design?

37. What is the main advantage of the layered approach to system design?

38. What is a batch system?

39. What are time shared systems?

40. What is RTOS?

41. What is a real time system?

42. Compare batch operating system and time sharing operating system.

43. Differentiate time sharing systems and multiprogrammed batch systems.

44. Compare Uniprocessor and multiprocessor systems.

45. What is SMP? List its characteristics.

46. What is multiprogramming? List its advantages?

47. Compare multiprogramming and multiprocessor systems.

48. What is multicore organization?

49. Discuss the difference between symmetric and asymmetric multiprocessing.

50. Mention the advantages in using multiprogramming systems.

51. What is the main advantage of multiprogramming?

52. What are the advantages of multiprocessor systems?

53. How does multiprogramming increase CPU utilization?

54. List out the three main advantages of multi-processor system.

55. What is context switch?

56. What is data parallelism?

57. What is task parallelism?

58. What are the three approaches to providing parallelism?

59. What is SYSGEN?

60. What is meant by system boot?

61. What is a boot strap program?

62. What is a boot disk?

Creating Menu in blogger

Creating Menu in blogger

Open blogger in design mode and Create posts. Group related posts with common labels (Eg: “Blog”, "Python")

Click “view blog”

Go to "Search this blog" and Enter the Common label under which to group the posts and hit search. copy the URL address. 
Example: The common label is "Blog"

Open blogger in design mode and click “Layout”

After header in “Cross column” Click "Edit" in “Pages – Pages gadget”

This opens “Configure Page List”

Click the “+ Add external link”

This opens the "New Page"

Set the common label as the title of Menu in Page title and add the copied address in web address (URL)

Eg :

Page title – Blog

URL – https://drranurekha.blogspot.com/search?q=Blog

This adds Blog as a Menu. When clicked all blog posts with “Blog” in Label will be listed. 


Happy blogging...
Dont be a silent reader!!!
Leave your comments...

Anu

10 Operating System Structure

9 System programs

8 System Calls