OS Services

Operating Systems Services:

1. Program execution:
  • The operating system Loads program into memory
  • It Handles the program’s execution
  • It Provides a mechanism for process synchronization
  • It Provides a mechanism for process communication
2. I/O operations:
  • OS manages the communication between the user and devices drivers.
  • I/O operations are the read or write operations which are done with the help of input-output devices.
  • Operating system give the access to the I/O devices when it required.
3. File system manipulation:
  • The OS gives an access to the program for performing an operation on the file.
  • The user can create/delete a file by using an interface provided by the OS.
  • The backup of the file system can be created by using an interface provided by the OS.
4. Communication:
  • The operating system manages communication between all the processes.
5. Error detection:
  • The OS continuously checks for the possible errors.
  • The OS takes an appropriate action to correct errors and consistent computing.
6. Resource allocation:
  • The OS manages all kinds of resources using schedulers.
  • CPU scheduling, Disk scheduling algorithm etc are used for better utilization.
7. Protection:
  • The OS ensures that all access to system resources is controlled.
  • The OS ensures that external I/O devices are protected from invalid access attempts.
  • The OS provides authentication features for each user by means of passwords.
Operating Systems:

EasyExamNotes.com covered following topics in Operating Systems.
    A list of Video lectures
    Python Programming ↓ 👆
    Java Programming ↓ 👆
    JAVA EasyExamNotes.com covered following topics in these notes.
    JAVA Programs
    Principles of Programming Languages ↓ 👆
    Principles of Programming Languages
    EasyExamNotes.com covered following topics in these notes.

    Previous years solved papers:
    A list of Video lectures References:
    1. Sebesta,”Concept of programming Language”, Pearson Edu 
    2. Louden, “Programming Languages: Principles & Practices” , Cengage Learning 
    3. Tucker, “Programming Languages: Principles and paradigms “, Tata McGraw –Hill. 
    4. E Horowitz, "Programming Languages", 2nd Edition, Addison Wesley

      Computer Organization and Architecture ↓ 👆

      Computer Organization and Architecture 

      EasyExamNotes.com covered following topics in these notes.

      1. Structure of desktop computers
      2. Logic gates
      3. Register organization
      4. Bus structure
      5. Addressing modes
      6. Register transfer language
      7. Direct mapping numericals
      8. Register in Assembly Language Programming
      9. Arrays in Assembly Language Programming


      1. William stalling ,“Computer Architecture and Organization” PHI
      2. Morris Mano , “Computer System Organization ”PHI

      Computer Network ↓ 👆
      Computer Network

      EasyExamNotes.com covered following topics in these notes.
      1. Data Link Layer
      2. Framing
      3. Byte count framing method
      4. Flag bytes with byte stuffing framing method
      5. Flag bits with bit stuffing framing method
      6. Physical layer coding violations framing method
      7. Error control in data link layer
      8. Stop and Wait scheme
      9. Sliding Window Protocol
      10. One bit sliding window protocol
      11. A protocol Using Go-Back-N
      12. Selective repeat protocol
      13. Application layer
      1. Andrew S. Tanenbaum, David J. Wetherall, “Computer Networks” Pearson Education.
      2. Douglas E Comer, “Internetworking with TCP/IP Principles, Protocols, And Architecture",Pearson Education
      3. KavehPahlavan, Prashant Krishnamurthy, “Networking Fundamentals”, Wiley Publication.
      4. Ying-Dar Lin, Ren-Hung Hwang, Fred Baker, “Computer Networks: An Open Source Approach”, McGraw Hill.