Operating System

In this Tutorial we discussed about #Operating system 

A group of programs that controls a computer’s resources such as the CPU, memory, and input/output devices and provides the users with an interface that makes it easy to use computers

Provides environment for execution of programs efficiently and conveniently Coordinates with the hardware devices First program loaded during the booting and remains in the memory all the time

 Functions of Operating System :

1. Command interpretation: -   OS enables the computer to understand the commands given by the users through keyboard or mouse . It also enables the computer to give the results based on the commands of the users.

2. File Management :-  The operating System manages the files in the system . it enables the users to create a file , save ,open and delete the file . It also renames a file or folder , coping the files , moving the files from one place to another place .

3. Memory Management :-  The operating system allots space for the files in the memory . The operating system only knows where the particular file has been kept in the system. When the user requires that file , the operating system will search and give the file to the user.

4. Input / Output Management :-  To run a program we need some values of input and output . The operating system not only provides the necessary values to all input and output parts but also controls them.

5. Security :-  User wants to  protect the data or files , Operating system allots a password to the used so that others can not see or change the files to other users .

6.Managing Hardware :- The operating system is the intermediary between programs and hardware .In a computer network os also mediates between your computer and other network devices. The three ways that an operating system infracts with hardware are processing interrupts , drivers and networking.

Evolution of Operating Systems

·        Single User Operating system.

·        Multi-User operating system.

·        Multi Programming Operating system.

·        Multi Processing.

·        Real Time / Online Operating system.

·        Batch Processing Operating System.

·        Time Sharing Operating System.

1.Single User Operating system :  In this type of operating system one person can operate on one system. We can not run more than one application here. If we want to open another programme , we have to close the current application or programme . The Best example is MS.DOS.

2. Multi-User operating system : Many persons can operate the system at the same time in this type of Operating system .the Best example is windows. One computer is the main here and there are subsidiary computers for other work . The main computer will be connected with CPU and other parts . where as in other computers , we will have only monitors and keyboards . These subsidiary computers are connected with main computer ( Server)

3. Multi Programming Operating system : In Multi Programming operating system , we can operate many programs at one time . We can open Notepad and type letter and we can hear audio at the same time . We can even make calculations on Excel without closing other applications.

4. Multi Proccessing : The operation of this type of oprtating system is same as above multi-program OS.The difference is we have many CPUs in multiprocessing system where as only one CPU in multiprogramming OS.Since we have more than one CPU , programs are processed very fastly in this multiprocessing OS where as the programs are executed one by one in multi programming Operating System.

5. Real / Online Operating Systems: in this type of computer many inputs and outputs are done at the same time with great speed.The computer processes the inputs and outputs at the same time.For example in Rail way Reservation and Banking Systems,many requests are processed by many users and the outputs are also processed at the same time.

6. Batch Processing Operating System : Batch means a collection of instructions. In this type of OS , the computer processes instructions in a Batchwise. This type of Operating system is used in Main Frame computers where thousands of instructions in Batch wise are processed.

7. Time Sharing Operating Systems : This type of OS CPU time is shared among many users. The users think that their instructions and commands are executed at that time . But the switching operation of the operating system which makes the users to think like that their work is executed at the same time.