Transcript Operating systems

AS Level ICT
Selection and use of appropriate
software: Operating systems
What is software?
• Software is the name given to all the programs that
run on computer hardware
• There are two main types of software:
– Operating software (also known as systems
software)
– Applications software
Operating systems
• An operating system is a program that controls the
hardware
• Operating systems perform the following tasks:
– They assist applications software to
communicate/interact with the hardware (e.g.
allow a word processed document to be printed)
– They manage the system resources (e.g.
allocate Central Processing Unit time to the
tasks being undertaken)
Operating systems
– They manage the transfer of data to and from
the systems peripheral devices (e.g. keyboard,
mouse, scanner, printer)
– They manage system security (e.g. allocating
restricted rights to users to do certain things)
Operating systems
• The operating system acts a a ‘shell’ around the
hardware
• The applications software need an operating
system to work, and users need the applications
software to interact with the hardware via the
operating system
Operating systems
Application
User
Application
Operating
system
Application
User
User
Hardware
Application
User
Multi-tasking
• Multi-tasking is the ability to do more than one
thing at a time.
• If an operating system can multi-task, it enables a
computer system to do several things at the same
time (e.g. A user can print a document whilst
reading their emails).
Multi-user
• A multi-user facility allows more than one user to
access data or an application program at the same
time
• Without a multi-user facility in an operating system
it would be almost impossible for a network to
function
Operating systems
• Examples of operating systems include:
– Windows Vista
– Windows XP
– Windows ME (Millennium Edition)
– Windows 2000
– Windows NT
– UNIX
– LINUX
– Macintosh OS
– OS/2
Operating systems - Windows
• Microsoft Windows is the most commonly used
operating system
• It works with a wide variety of different computers
from different manufacturers
• It has been constantly developed since it was first
introduced in 1983
Operating systems - Windows
• Windows 3.0 first went on sale in 1990
• It was followed in 1992 by Windows 3.1, which was
one of the first major PC GUI (graphical user
interface) operating systems widely used.
• Windows 3.1 allowed users to utilise several new
features including the use of a mouse to navigate
and manipulate data on the computer
• In addition, the user did not have to memorize MSDOS commands
• Windows also allowed the user to multitask
Operating systems - Windows
Windows 3.0
Operating systems - Windows
Windows 3.1
Operating systems - Windows
• Windows 95 was the next stage of development
• It introduced new features including:
– Plug and Play – this allows hardware devices to
be automatically installed into the computer
– 32 Bit Operating System – this allows the
computer to run faster and more efficiently
– Right mouse click – This allows users to
access and manipulate text by utilising both
mouse buttons
Operating systems - Windows
Windows 95
Operating systems - Windows
• Windows 98 introduced further new features
including:
– Protection – additional protection for important
files was introduced, including automatically
backing up the registry
– Improved support – the support for new
devices (including DVD, USB, and MMX) was
improved
– Plug and Play – the ability to detect devices
was improved
Operating systems - Windows
– Internet Explorer 4.0 – this was included within
the Windows 98 package
– Customisable Taskbar – users were now able
to customise the taskbar
– Active Desktop – users were now able to
customise their active desktop so that it looked
like the Internet
Operating systems - Windows
Windows 98
Operating systems - Windows
• Windows ME (Millennium Edition) allowed users of
Windows 95 and 98 to upgrade their operating
systems to include:
– Revert back to backup – users could
automatically restore an old backup if files
became corrupted or were deleted
– Protect system files –important system files
were protected from being modified by other
software
Operating systems - Windows
– Movie Editor – it became possible to edit and
combine Microsoft movie files
– Windows Media Player – enabled the use of
more advanced methods of listening to and
organising media files
Operating systems - Windows
Windows ME
Operating systems - Windows
• Windows XP (XP stands for ‘experienced’) was a
radical redesign of the Windows operating system
that included:
– New interface – the user interface looked
completely different and was capable of
customisation
– Updates – the operating system could be
automatically updated via the Internet
– Internet Explorer 6 – this enhanced web
browser was included in the Windows XP
package
Operating systems - Windows
– Multilingual support – support for different user
languages was included
– Reliability – the operating systems reliability
was enhanced
Operating systems - Windows
Windows XP
Operating systems - Windows
• Windows Vista is the latest development of the
Windows operating system
• It looks very different from previous versions of
Windows and has been designed to give users a
better overall experience
• Vista’s key features include:
– Windows Aero (Authentic, Energetic,
Reflective, and Open) – a completely new-look
GUI
– Basic file backup and restore facility
Operating systems - Windows
– Improved DVD support – this enables the user
to create custom DVD movies
– Easy transfer – this feature assists the user to
transfer files from an older to a newer computer
– File encryption
– Instant search – the Explorer windows permit
instant searches to be undertaken
– Support for DirectX 10
Operating systems - Windows
– Self-healing – the computer can automatically
detect and correct any problems that may be
encountered
– Shadow copy – this allows the user to recover
deleted files
– Improved photo gallery and control of
photographs
– Windows Sidebar – this feature allows the user
to add different hardware devices
Operating systems - Windows
– Improved parental control
– Improved Windows Calendar – this allows the
user to easily set tasks and appointments
Operating systems - Windows
Windows Vista
Operating systems - UNIX
• UNIX has evolved since it was first introduced in
1969
• It is a powerful multi-tasking operating system that
was developed for use in a minicomputer
environment
• It is still a widely used network operating system,
especially by universities and ISPs (Internet
Service Providers)
• It uses a mixture of GUIs (Graphical User
Interfaces) and command line interfaces
Operating systems - UNIX
• The main features of UNIX are:
– It is written in the programming language C
– It is a multi-programming operating system
– It is a multi-tasking operating system
– It can be used to run hundreds of terminals
Operating systems - Linux
• Linux is an open source (i.e. free) operating system
• It is mainly used as server software, although its
popularity with other users is growing
Operating systems – Macintosh OS
• The Macintosh operating system was developed by
Apple in 1979, when Apple launched the ‘Lisa’
computer
• It was the first commercial operating system that
made use of GUIs (Graphical User Interface) – this
pre-dated the use of GUIs by Microsoft in 1983
when they launched Windows 1.0
• The Macintosh (also know as Mac) operating
system is particularly popular with users who are
involved with graphic design
Operating systems – OS/2
• OS/2 is and operating system that was developed
originally by Microsoft Corporation for IBM
• It was intended to be the operating system for IBM
PCs that used Intel's 80286 and 80386
microprocessors
• Microsoft withdrew from the development of the
operating system, and its further development was
managed solely by IBM
• OS/2 is compatible with DOS and Windows, and it
can run all DOS and Windows programs
Operating systems – OS/2
• However, programs written specifically to run under
OS/2 will not run under DOS or Windows
AS Level ICT
Selection and use of appropriate
software: Operating systems