7th Class Computers Science Understanding Basic Concepts of Operating System Basic Concepts of Operating System

Basic Concepts of Operating System

Introduction

The word operating system is self-indicating that this is a system for operating a devise. An operating system is a program which acts as an interface between a computer hardware and users of the computer. It provides such an operating system, the primary goal is to make computer system convenient to use and the secondary goal is to use the computer hardware in an effective manner. The OS helps in a file management, program execution, system management and memory management. Some popular operating system are: LINUX, Window, OSX, VMS, AIX OS/400, Z/OS etc.

Main Layers in an Operating System       

Layers in an Operating System is defined as the software which provides interface between different components of the computer. The following five layer model is often used in an Operating System.

• Kernel: It connects the application software to the hardware of a computer. Hence, it manages memory access for programs in the RAM. It also allocates processor time and memory to each program and determines when each program will run.
• Memory Management: It is responsible for starting the physical memory of the computer between processes and handling programs which require more memory than physically available.
• Input/Output: This layer controls all physical communication with external devices like disk drive, keyboard, printer and display. If a higher layer require access to a device, a request is sent to the I/O layer.
• File Management System: It is also known as file system. It is responsible for organising and managing the storage of data on permanent media such as hard and floppy disk drives and tape streamers.
• User Interface: It is defined as the space where interaction between human and machine occurs. There are two types of user interface: the text-based Command Line Interface (CLI), used in MS-Dos and LINUX, and the icon-based Graphical User Interface (GUI), used in windows and Apple Mac OS.

Classification of Operating System is as follows:

v  Multiprocessing: Supports in running a program on multiple CPUs within a single computer system.

v  Multitasking: Allows you to run more than one program at the same time.

v  Multi - user: Allows multiple user to run the program at same fraction of time.

v  Multithreading: Permits all different modules of a single program to run at the same time.

v  Real - Time: responds to input immediately.

Microsoft Windows

Microsoft windows is a type of Operating System available in 32 and 64 bit versions. It was developed by Microsoft. It provides a Graphical User Interface (GUI), virtual memory management capabilities, multitasking functionalities and support for many peripheral devices.

Earlier in Microsoft Windows Operating System, there was no graphical interface to operate a computer and utilize its resources. User had to know the overall commands with their correct and complete syntax.

Regardless of IBM's interest, Microsoft continued with development of the GUI. After completion of its development, the new Operating System, Windows is named by Microsoft and thus in 1985 the first version was released in market.

The following are different versions of Microsoft window:

Windows 10 is the latest version from Microsoft. Windows 10 is a personal computer Operating System developed and released by microsoft in July 2015 as a part of the windows NT. This Operating System includes improved support for biometrics authentication through the Windows Hello. The full screen start menu is used in this mode, similar to Windows 8, but scrolls vertically instead of horizontally. The major change in windows 10 is the introduction or new default web browser, 'Microsoft Edge', which is designed to replace Internet Explorer (IE) and Cortana - the personal assistant.

UNIX

UNIX is one of the time sharing Operating Systems primarily intended for program development and document preparation environment. It is a set of programs that act as a link between the user and the computer. The first version of UNIX was written by Ken Thompson, later joined by Dennis Ritchie. It was a single user system written for the PDP-7 in assembly language. Several specialized versions of UNIX, such as the programmer s Workbench, UNIX/ PWB and Writer's Workbench, UNIX/WWB are also available.

Some of the major features of UNIX are as follows:

v  Hierarchical file system.

v  Device Independence.

v  Multitasking.

v  Multi-user operation.

v  Tools and tool-building utilities.

v  Portability

v  Built-in networking.

LINUX

The LINUX Operating System is one of the popular versions of Unix OS. It is freely distributed open source Operating System whose source code is freely available on the internet and can be modified by anyone who uses it. Its functionality list is very much similar to that of Unix. The limitation of the freely distributed Operating System is that the changes made in the original source code are to be redistributed over the internet.

BOSS LINUX Operating System or Bharat Operating System Solution LINUX is an open source which is promoted and distributed by the CDAC government of India. The BOSS LINUX can be downloaded from the internet. The BOSS LINUX Operating System has the feature to use both mouse and keyboard as input devices. '

The LINUX Operating System was created by a student named LINUX Torvalds.

The features of LINUX Operating System are as follows:

v  Anyone can modify the source code of LINUX and redistribute it. Hence, it is an open source Operating System.

v  LINUX Operating System provides better security and hardly gets affected by computer viruses.

v  LINUX operated computer does not hang, therefore, anyone can run LINUX for days and months without the need to restart the computer. This is the reason for using the LINUX Operating System in most of the internet servers.

v  The LINUX operated computer allows the user to use four desktop screen simultaneously. A user can switch anytime from one desktop screen to another.

v  LINUX offers a standard file structure in which system files or user files are arranged.

v  LINUX kernel and application programs allows their installation on any type of hardware platform.