Evolution of OS

Evolution of OS:

Evolution of OS is divided in 5 phases:
Phase 0: (1940-1955): 
  • Computers are exotic experimental equipment. 
  • Program in machine language. 
  • Use plug boards to direct computer. 
  • No overlap between computation, I/O, think time, and response time. 
  • Programs manually loaded via card decks.
Phase 1 (1955-1970):
  • User at console: one user at a time 
  • OS becomes a batch monitor. 
  • OS were written in Assembly languae.
  • No structured programming.
  • More efficient use of hardware. 
  • No protection 
  • difficult to debug!
Phase 2 (1970-1980): 
  • Interactive timesharing. 
  • One of the first timesharing systems. 
  • To let multiple users interact with the system at the same time.
  • Users do debugging, editing, and email online.
  • More than one user executes their tasks simultaneously.
Phase 3 (1980-1990):
  • Created MS- DOS. 
  • GUI operating systems was developed first time. 
  • Microsoft Windows: Win 1.0 (1985) .
  • Phase 4 (1990-2000):  
  • Networked Systems: (LAN). 
  • Different machines share resources, printers, File Servers, Web Servers.
  • Internet service providers (service between OS and apps). 
Phase 5 (2000-present): 
  • Mobile and computer operating systems have been developed in different ways and for different uses. 
  • Computer OS products are older and more familiar to larger groups of users. 
  • Through this time, Microsoft Windows and Apple's Mac OS have emerged as the two dominant operating system designs.
  • So many types of GUI operating systems are develop in phase 5 major types are: OS system of mobiles. window 95, window 98, window XP, window crystal vista window 8, window 10.
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.