Operating Systems

Operating Systems System Software, functions of an operating system

The Operating System The Operating System is also

known as System Software.

All computers must have an operating system in order to work

The OS is responsible for all the functions of hardware and also software

Functions of an Operating System

GUI

Device Drivers

Security Networking

Disk Management (File

Systems)

Memory Management

Process Management

Operating System

Process Management A multitasking OS allows the computer to

perform many different tasks(processes) at the same time

The CPU can only focus on one process at a time. The OS tells the CPU to give each process a very short time slice (time slot)

This happens very fast making it seem like the processes are occurring at the same time

Memory Management A computer has different memory

types it could use; memory registers, cache, RAM and disk storage.

The OS is responsible for checking; which memory if free which memory is to be allocated and de- allocated how to swap between the main memory and secondary memory

Memory Management When the OS swaps between main

memory and secondary memory we call this Virtual Memory management

Virtual memory creates a memory slot acting as RAM when the RAM is too full

Virtual memory is much slower than RAM

Disk Management / File SystemsOperating systems have different file

systems.

A file system is an organisation of all the files and folders saved within

the computer

Each OS has a different file system hence a different access system (notes page 29)

Networking Most of the OSs today are

capable of using the universal TCP/IP (Transmission Control Protocol/Internet Protocol)

This allows computers to communicate with each other and be able to share resources such as files and hardware devices over a network, such as Internet.

SecurityThe basic type of security an OS

offers is asking for a Username and Password before a user can use the OS

The OS could also limit certain users from doing certain actions. This is known as level access

The OS uses a Firewall to close certain ports when using TCP/IP protocol

GUI – Graphical User InterfaceMost operating systems use a GUI –

Graphical User interfaces, which is more user-friendly as it uses graphical representations which the user can easily understand.

A GUI's components are Icons, Menus, Windows, Toolbars , Buttons amongst others.

Windows GUI

Linux GUI

MAC GUI

Device Drivers A device driver is software that is

responsible for the communication between different hardware and the computer.

Device drivers are used to let the OS know how a specific hardware works as with all the new advances in technology it is impossible for the OS to know how ALL types of hardware work