Lessons on Operating Systems for S.H.S

What is operating system (os) ? The Types , Functions and examples .   

An Operating system (OS) is a program that acts as an interface between a computer systems user and the computer hardware. It provides a user-friendly environment in which a user easily develop and execute programs. Which shows that before the computer need to operate it is the Operating system (os) and also before the user have to use the computer it is the operating system that take place.

 

Examples of the Operating system are:

•     Mac OS.                           I                 

  

      

  Microsoft Windows

                        

 

And others know as:

-     Palm OS.

-     IBM OS/2.

-     IBM OS/360.

 

 Main Functions of the Operating System

◻        Processor Management

◻        Memory Management

◻        File Management

◻        Device Management

◻        Security

 

The processor in a computer running Operating System has two different modes: user mode and kernel mode.

All Operating system runs in a kernel mode and all Application software runs in the user mode

In the kernel mode there are no restriction but in the user mode there are restrictions that before an application should run in the kernel mode it must ask for system call or request for a specific purpose. But the a two things running in a kernel mode it can cause a complete halt of the computer

In the user mode, the exciting code has no ability to directly as he is hardware or interference memory normally or application software runs in the user mode

The key discovery that changes the evolution of OS/ Types of Operating System

Multiprogramming: in multiprogramming there is effective utilisation of CPU time by allowing several programs to use CPU at the same time

Timesharing. OS : a timeshared system uses cpu scheduling and multiprogramming to provide each user with a small portion of a timeshared computer

Realtime.  OS : is an operating system intended to save real-time applications that process data as it comes in most without buffer delay

Network OS : network operating system helps to manage data uses group securities and on the network related functionality

Desktop  OS : is the environment to which the user controls a personal computer .Examples are Windows macOS linux IOS

Distribution OS:  the distributed operating system uses multiple central processes to save multiple real-time applications in multiple uses .Data processing jobs are distributed among the processor accordingly. 

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CLASS    :  SHS3

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