Mr C JohnstonICT Teacher

www.computechedu.co.uk

BTEC IT Unit 02 - Lesson 06

Computer Software

Session Objectives Understand the role of the Operating Systems and common examples, Know the differences between CLI and GUI operating systems, Understand the role of device drivers, Know different types of utility software that are used to keep computers

systems running smoothly.

Software Overview A useful way of looking at the types of software used in

a computer is:

Operating System

Provides two classes of service: Provides access to the computer hardware and peripheral

devices, Provides an Application Program Interface (API) so application

software can be displayed, print, communicate with the world and store data.

The operating system includes a number of accessory programs which offer machine and peripheral management, security and file management.

Two types of operating system: Command Line Interface (CLI) Graphical User Interface (GUI)

CLI Characteristics Text based interface with a command prompt,

The user types in instructions at the command point using a keyboard,

The operating system then responds to the commands keyed in,

When the instruction had been processed doing the command prompt would reappear ready for the next instruction,

A high level of knowledge is required to remember and construct the commands.

GUI Characteristics Graphical based interface made up of WIMPs –

Windows, Icons, Menus and Pointers, Users enter commands by clicking on an option in a menu, pressing a button or completing boxes on a form, The interface is far more user-friendly and it opened up the use of computers to people who had not learnt

how to program a computer or can’t remember a lots of commands.

CLI vs GUI

Common Operating Systems

UNIX – Command Line

DOS – Command Line (PC-DOS – IBM, MS-DOS – Microsoft)

Linux – Command Line - Ubuntu – GUI

Windows 95, NT, 98, ME, 2000, XP, Vista, Windows 7 Novell Netware – Command Line With GUI Applications

Windows NT, 2000, 2003, 2008 Server – GUI

MAC OS – classic version 1984 - 2001

MAC OS X – first stable release 2001, current version v10.7 (Lion)

OS Choice Factors Does the operating system let you customise what you see

on the screen and how you interact with the computer? Does it provide support for connectivity of portable media? What provisions are there to ensure tight security of the

computer system? What guarantees do you have of stability and reliability? How easy is it to manage the computer system? What utilities are included? How much does it cost? What after sales support is on offer for the user?

BTEC Book – Unit 02 p14/15

Device Drivers In order for the OS to function correctly it must be able

to communicate with all hardware devices attached to the computer,

A device driver are instructions for the OS on how to communicate with each device,

In order for a piece of hardware to work properly its own driver needs installing – it also must be the correct version for the operating system you are running,

In windows you control device drivers within device manager – part of the control panel

Task 2[P2, M1] You need to make notes about the tasks which operating systems

enable us to do and compare different operating systems within perhaps a table.

Features and functions to discuss include: machine and peripheral management, security, file management, device

drivers, ability to customize, support for connectivity of portable media, stability and reliability, ease of management, associated utilities, cost and support for the user

• For P2, you should outline the basic functions of operating systems in general, explaining how they are used to facilitate users.

• For M1, you must review the features and functions of different operating systems. Learners will need to present a comparison of selected operating systems, summarising their respective strengths and weaknesses in context.

P2 - Explain the purpose of operating systemsM1 - Compare the features and functions of different operating systems

P2 - Explain the purpose of operating systemsM1 - Compare the features and functions of different operating systems

Expansion -

P2 What is an operating system forwhy needed / what is its purpose

What services do operating systems providethings that it allows users to do

Different types of operating systemCLI / GUI - =ve / -ve of each

Examples of different operating system brands

M1 Table comparing the features of different operating systems with a conclusion about the +ves / -ves of each

Feature OS 1 OS2 OS3 etcFeatures from slide 9 & any others you can think of

Overall Benefits (+ves)

Overall Limitations (-ves)

Operating System Features

General features Random screen shots First released Current version Cost / Availability Architectures supported Minimal hardware requirements GUI / Command line Customisable GUI Target system type File systems supported Installation overview International support

User friendly for lay users Security features provided Integrated firewall Encrypted file systems Security threats Stability and reliability Kernel type Connectivity of portable media How easy is it to manage the

computer system? Included utilities / apps What after sales support is on

offer for the user?