as ict (ocr) g061 3.1.2 sofware & hardware components lesson slides

1 October 2009C. Demetriou (2009) 1


ûHardware:› Physical equipment that makes up a computer

system.› If you can kick it or take an axe to it, it is hardware.

ûSoftware:› Programs, routines and procedures (together with

their associated documentation) which can be run on a computer system.

It is important not to confuse the media used to transport software with software itself!

› A CD is a piece of hardware which you can touch and kick and it may contain software which you cannot touch. The CD is not software!


Examples of Hardware

û Central Processor (CPU)

û Peripherals – these are hardware devices which are attached to the central processor.

They can be classified into 4 types:

û Input:› Keyboard, Mouse, Scanner

û Output:› Monitor, Speakers

û Backing Storage:› Hard Disk, Flash Drive

û Communications:› Modem


û Standardisation is the imposition, by a third party, or with agreement, of a set of standards on manufacturers.

› W3C : the world wide web Consortium› ISO : International Standards Organisation

û ICT suffers from a lack of standardisation for both Hardware & Software.


û Lack of standardisation has the following disadvantages› Cost› Availability› Technical Support

û Software› Word Processors should all use the same file format

but do they?› Do all web browsers display web pages in exactly

the same way?û Hardware

› Do all PCs accept the same hardware upgrades?› When buying a game for a PC what must you

consider?


û Takeovers› When a company gets taken over there is

likely to be incompatibility between their own systems. This may be down to the two companies having separate standards.

› This leads to:-ñ No communication between systemsñ Miscommunication between systems

(incorrect data being shared)ñ New equipment having to be purchasedñ Staff training ñ Lack of tech support on new systems


û An input device is a piece of Hardwarethat gets data from outside the computer system into the computer system› Keyboard› Mouse› Scanner› Graphics Tablet› Digitiser


û Output devices are used to display the result of processing to the user. They are used to get data from inside the computer to outside.› Monitor (LCD, CRT)› Printer› Plotter› Loud Speakers› LEDs› Buzzer


Loud Speaker

û Used to give confirmation of actionsû Can be used to read lines of textû Increased use with CDs and Music

(MP3s)û Music technology requires specialist

sound output devices.


LED and Buzzer

û LED› Can display the status of a deviceñ HDD light displayed when in useñ Lights on a Printer indicates statusñ Can be used to signal to hearing impaired

people

û Buzzers› Gives confirmatory actionsñ Set sounds to events in Windowsñ Bar Codes beep to indicate successful entry


Monitor (VDU)

û Most common Output deviceû Range of Sizes – standard is 17”, but 19”

or 21” available for specialists, › For example, designers› Newspapers and magazines

û High quality outputû Possible health issues


û Three main types of printers:› Impact/Dot matrix Printers› InkJet Printers› Laser Printers

û Choice of:› Colour› Black and White

û Selection of different resolutions. › DPI [Dots per Inch]


û Physical Connection between print head and paper

û Noisyû Slowû Cheap to runû Colour or Black and Whiteû Low Resolutionû Can do Carbon Copies


û Ink is fired at the page and the number of DPI can be very high› High resolution

û Colour or B&Wû High Running Costsû Faster than a Dot Matrix but not as fast

as laserû Cannot print Carbon Copies


û High Quality Imagesû Fast Printingû Colour or Black and

White (Colour is expensive)

û Medium to low running costsû Excellent Qualityû Can produce OHTsû Cannot do Carbon Copies


û Storage devices are used to hold data and programs.

û They are non-volatile.› Floppy Disks [now obsolete]› Hard Disks [SSD’s on the horizon]› Optical Disks (CD, DVD, Blu-ray)› Tape Drives› Flash Memory (MMC, SD, CF, xD, MS)

û Sometimes referred to as mass storage.


û Motor Impairment is the loss or limitation in muscle control or movement, or a limitation in mobility. › Mouth stick› Puff-Suck Switch› Tongue-activated joystick› Eye-typer› Foot mouse


û Specialist software can help people with disability› Text to speech› Speech to text› Auditory feedback (windows sounds)› Screen magnifier› Predictive text› Sticky Keys

û Which are available in a standard install of Windows?


û Operating Systemsû User Interfacesû Utilitiesû Applications

Hardware

Operating System

Utilities

Applications


û A program or suite of programs that control the entire operation of the computer.

û Deals with the basic functions of the computer.

û At a technical level, it handles the basic and central functions such as input and output operations and interrupts.

û Examples include: MS-DOS, Win 2000, Win XP, UNIX, Linux, FreeBSD, Symbian, MacOS


User Interfaces

û These are pieces of software which fit onto existing packages to alter the user interface.

û More commonly, they are now referred to as “Skins”

û They allow for individual customisation of the user interface


û Command-Basedû Formsû Menusû Natural Language

The user interface is the

method by which

the user communicates

with the computer.


û Command Promptû Commands are typedû Each command can have switches

› These are different modes in which the command can be run.

û Expert users only


û Data Labels giving assistanceû Boxes to enter/choose dataû Used for Data entry (records)û Making choices is easierû The user is given choicesû Useful for novice users


û Series of related items which can be clicked

û Presents a limited choice

û Novice-friendlyû Structured into

options


û User types or speaks in normal everyday language and the computer responds

û Used in Microsoft Help and Ask Jeeves Web Site

û Useful for novice users as they do not need to understand the computer to use it.

û With vocal input, useful for physically handicapped people.

û Hand writing recognition on PDAsand Nintendo DS


û GUI (Graphical User Interface)› This is an interface that is based on graphics

and pictures rather than text.û WIMP (Windows, Icons, Mouse, Pointer)

› This is a particular type of GUI.

ALL WIMPs are GUIs, but not all GUIs are WIMPs


û Designed to perform a commonplace task, for example the transfer of data from one storage device to another, sorting a set of data, disk editor.

û They are designed to make the operation of the computer easier.› Windows Explorer› Defrag› Anti-Virus› Anti-Spyware› Burning CDs/DVDs› File Compression› Printer monitoring


û Genericû Tailor-Madeû Off-the-shelf


û These are off-the-shelf packages which do not meet a specific purpose but serve a general purpose

û For example:› Microsoft Office and components› Corel Suite› Adobe CS suite› Lotus Suiteñ Word Processors, Spreadsheets, Databases

û The software can then be customised to produce the result you want.


û Either:› Bespokeñ The application is written for the purpose by a

software houseñ Disadvantages: Time consuming, expensive, limited

support/books.ñ Advantages: Fulfils purpose, individual support

û Or:› Customisationñ A generic application is customised using a

programming languageñ Disadvantages: Need to purchase the application and

you get more than required.ñ Advantages: Cheaper, lots of support.


û Purchasing solutions from a shop without alteration

û For example:› SAGE payroll package› Heritage Library Database

û The idea is to be able to open the package and run the software which delivers a specific solution.

as ict (ocr) g061 3.1.2 sofware & hardware components lesson slides

Education

hardware software

hardware devices

piece of hardware

hardware upgrades

specialist software

high high resolution

colour black

white colour