Download 10-Software-Presentation

Computer
Systems
Nat 4/5 Computing Science
Software
Lesson Aims
 By
the end of this lesson:
 All pupils will be able to:


Describe what an operating system is
Describe the functions of an operating system
 National



5 pupils will be able to:
Describe a web browser
Describe what an application program is
Describe some utility programs
Nat 4/5
Types of software
 Operating
Systems - controls the
computer and devices that are
attached to it
 Web browsers – display web pages
 Applications
- performs a particular task
e.g. word processing or desktop
publishing
 Utility
programs – useful programs
Nat 4/5
Operating Systems
 An
operating system is software that
controls the operation of the
computer
 Two of the more popular operating
systems used at present are
Microsoft® Windows
Apple® OSX
 There
are many others
Booting-up
 When
computer is switched on part
of the operating system called the
bootstrap loader (in ROM) is run
 This
loads the rest of the operating
system from disk and puts it into RAM
 The
operating system runs all the time
when the computer is on
Platform
 “Platform”
means hardware and software
that make up a computer
 2 popular platforms: Mac platform – runs Mac Os operating
system
 PC Platform – runs Windows operating
system
 Single platform software runs on 1 platform
 Dual platform software runs on both
platforms
Software/system requirements
 When
buying application software
check the system requirements to
ensure it runs on your platform
Photoshop CC 2014 system
requirements
Nat 5
Functions of an operating system
 Provide
a Human Computer Interface
(HCI)
 Handles input and output
 Memory Management
 File management
 Error reporting
 Manages the security of the
computer – manages users and
passwords
Nat 5
Operating System Functions: Provide a
Human Computer Interface (HCI)
Lets
the user give commands and see the
effect of their commands
Graphical
User Interface – icons
Command
commands
line interface - user types
Nat 5
Functions of an Operating System
– Handles Input and Output
 Sends
and receives data to and from
peripherals
Nat 5
Functions of an Operating System
– Memory Management
 Decides
which locations in RAM each
program is loaded into
Nat 5
Functions of an Operating System
– Memory Management
 Allocates
data
space in memory for programs &
 Allows
multi-tasking – more than 1 program
in memory at a time that user switches
between
 Prevents
operating system in RAM being
overwritten by user’s programs and data –
memory protection
Nat 5
Functions - File Management
 Decides
where files are saved on
backing storage and finds files when
they to be loaded
Functions - File Management
 Organises
files in hierarchical
filing system
 Allows
of files
Directory
Sub-directory
a logical arrangement
 Same
filename can be used
in different directories
File
Nat 4/5
Functions of an Operating System
– Error Reporting
 Provides
useful feedback to users
when errors occur
Nat 4/5
Operating System Summary
The Operating System (OS) is a program
which manages the computer and the
peripherals attached to it
 The functions of an OS are:
 Provide a Human Computer Interface
 Handle Input and Output
 File Management
 Memory management
 Error Reporting
 Provides security

Questions
1.
2.
3.
4.
5.
6.
What is an operating system?
What is a platform?
Where is the bootstrap loader
stored?
When does the bootstrap loader
run?
Describe what the bootstrap loader
does.
When does the operating system
program run?
More questions
7.
8.
9.
What is a dual platform application?
Why is it important to check system
requirements when buying an
application?
State the function of the operating system
that:a)
b)
c)
Decides where each program is stored in
RAM
Locates a file on disk when it is to be
loaded
Allows the user to give commands
Pupil Task
Pick three different operating
systems and find the following:
 Its
latest version (name or Number)
 Three features of the OS
 One recent news article about the
OS (recent being in the last year)
Web browsers
 Lets
user browse the World Wide Web
 Loads web pages from web servers
 Displays web pages on user’s
computer
 Examples
 Internet
are:-
Explorer
 Mozilla Firefox
 Safari
 Google Chrome
Web browsers
Html file that
browser loads
from web server
Web page that
browser displays
Nat 5
Applications Software
 Programs
that are designed to do a
particular task
 E.g. Microsoft Word, games,
Photoshop
Utility programs
 Perform
everyday tasks
 Either part of the operating system or
separate programs
 E.g.: Emulator – enables your computer to run
software that was created for a different
platform
 Virus checker – detects and removes
viruses
 Defragmenter – tidies up hard disk
 Backup – creates backup copy of files
Even more utility programs!
 Converters,
compressors &
expanders
 Installers/uninstallers – copy
program to hard disk or remove it
 Printer drivers – enable the
computer to send the correct
signals to the printer
 Email filter & web filters
Web browsers and utility program
questions
10.
11.
12.
13.
14.
Describe the function of a web
browser
Name 3 utility programs that you
have used
Why would you use an emulator?
Why would you use a compressor?
Which utility program is essential if
your computer is connected to the
internet?