COMPUTER SYSTEM SOFTWARE

                                OPERATING SYSTEM

An operating system (OS) is system software that manages computer hardware and software resources and provides common services for computer programs. All computer programs, excluding firmware, require an operating system to function.

Time-sharing operating systems schedule tasks for efficient use of the system and may also include accounting software for cost allocation of processor time, mass storage, printing, and other resources.

For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware ,although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers.

WORKING IN MICROSOFT WINDOW ENVIRONMENT

START BUTTON

The Start menu is a user interface element used in Microsoft Windows since Windows 95 and in some other operating systems

Where is the Start button and what does it do?

By default, the Windows Start button is found at the bottom left part of the desktop screen. However, the Start button        can be placed at the top left or top right part of the screen by moving the Windows Taskbar. Clicking the Start button opens the Start Menu(except in Windows 8) that gives you access all the programs installed on the computer and other Windows features. Below is a visual example of the Start button and its location on Windows 7......

BASIC LINUX OPERATION

BASIC LINUX OPERATION

What is UNIX?

UNIX is an operating system which was first developed in the 1960s, and has been under constant development ever since. By operating system, we mean the suite of programs which make the computer work. It is a stable, multi-user, multi-tasking system for servers, desktops and laptops.

UNIX systems also have a graphical user interface (GUI) similar to Microsoft Windows which provides an easy to use environment. However, knowledge of UNIX is required for operations which aren't covered by a graphical program, or for when there is no windows interface available, for example, in a telnet session.

Types of UNIX

There are many different versions of UNIX, although they share common similarities. The most popular varieties of UNIX are Sun Solaris, GNU/Linux, and MacOS X.

Here in the School, we use Solaris on our servers and workstations, and Fedora Linux on the servers and desktop PCs.

The UNIX operating system

The UNIX operating system is made up of three parts; the kernel, the shell and the programs....