Download 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
Process
Management
Memory
Management
GUI
Operating
System
Device
Drivers
Security
Networking
Disk
Managem
ent (File
Systems)
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 Systems

Operating 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.
Security

The 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 Interface

Most 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