2.3.1.2 State the functions of OS.

The main functions of OS are:

• starting a computer
• providing a user interface
• managing data & program
• managing memory
• configuring devices

Starting the Computer
The first function of an operating system is to start the computer. This process is called booting. Booting means to load & initialize the operating system. It can happen in two ways: warm boot or cold boot.
A warm boot means restarting a computer that is already on. It normally happens after installing a new software or hardware or after an application crashes or stops working.
A cold boot means starting a computer that is already off. It happens when we turn on a computer that has been completely powered off.
Providing a User Interface
This function controls how the user enters data and instruction and how information is displayed. The three type of user interface are Command-Line, Menu-Driven and Graphical User Interface . The user interface typically enables users:
to start an application program
to manage disks and files such as formatting, copying and renaming
to shut down the computer safely by following the correct procedures
Managing Data & Programs
When we start an application, the CPU loads the application from storage into memory. In the early days, single-tasking operating systems could run only one application at a time. Multitasking operating systems enable users to work with two or more application programs at the same time.
Managing Memory
The computer's operating system is responsible for managing memory such as:
· optimizing the use of RAM
· allocating data & instruction to an area of memory while being processed
· monitoring the contents of memory
· releasing data & instructions from being monitored in memory when the process is done
Configuring Devices
Another function of an operating system is handling input and output, as well as enabling communication with input and output devices. Most operating systems come with drivers for popular input and output devices. These drivers install new devices and check whenever there is conflict with these devices.