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Page 1: Year 10 ICT Booklet

Student Name:Group Name:

Page 2: Year 10 ICT Booklet

3. Theory Requirements8. Components of Computer11. Software13. Types of Computers16. Input Devices19. Output Devices21. Printers23. Storage Devices27. Protecting Data31. Communications32. Communication Media36. Computer Networks 39. Databases44. Validation & verification47. Software copyright49. Social effects of ICT53. Health & Safety56. WP v DTP59. Graphics Production62. Spreadsheets67. Data Logging & Control Software71. Presentation Software72. Web pages

Some of the notes provided in this booklet have been taken, or adapted from www.klbschool.org.uk, www.teach-ict.com as well as Information and Communication Technology for GCSE (2nd Edition) Hodder & Stoughton. All past exam questions (unless stated) have been taken from OCR ICT Short course papers.

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Theory Requirements

By working your way through this booklet you should meet all of the learning outcomes ready for your exams.

If you do not understand any of the topics or wish to investigate them further remember that there are textbooks available as well as your teacher!

Good Luck!

5.1.1 Computer Systems: Components and Types of System

(a) Hardware components of a computer system(b) Software: definition and examples(c) Laptops/notebooks, palmtops and other portable systems(d) Desk-top computers

Learning OutcomesCandidates should be able to:(i) define hardware, giving examples;(ii) define software, giving examples;(iii) describe the difference between hardware and software;(iv) identify the main components of a general purpose computer: Central Processing Unit, Main/Internal Memory, Input Devices, Output Devices and Secondary/Backing Storage;(v) describe the difference between portable (including laptops/notebooks and palmtops) and desktop computers.

5.1.2 Input and Output Devices

(a) Input devices: identification and use(b) Output devices: identification and use(c) Advantages and disadvantages of different types of input/output device

Learning OutcomesCandidates should be able to:(i) identify the following input devices: keyboards, pointing devices (including mouse, touch, pad and tracker ball), video digitizers, remote controls, joysticks, magnetic stripes, scanners, digital cameras, microphones, sensors, MIDI instruments;(ii) identify suitable uses of the input devices in (i) above, stating the advantages and disadvantages of each;(iii) identify the following output devices: monitors, printers (laser, ink jet and dot matrix), plotters, speakers, control devices (including lights, buzzers, robotic arms and motors);(iv) identify suitable uses of the output devices in (iii) above, stating the advantages and disadvantages of each;(v) identify relative purchase costs, running costs, quality and speed of different types of printers.

5.1.3 Storage Devices and Media

(a) Backing/Secondary storage devices and media: different types and uses(b) Advantages and disadvantages of different types of backing storage media(c) Importance of backups(d) Difference between main/internal memory and backing storage

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Learning OutcomesCandidates should be able to:(i) Describe common backing storage media (such as magnetic tape, CD-ROM, floppy disc and hard disc) and their associated devices;(ii) Identify typical uses of the storage media in (i) above;(iii) Describe the comparative advantages and disadvantages of using different backing storage media;(iv) Define the term backup and describe the need for taking backups;(v) Define the difference between main/internal memory and backing storage, stating the relative benefits of each in terms of speed and performance.

5.1.4 Introductory Communications

(a) Modems and digital telephone lines(b) Analogue to digital conversion and digital to analogue conversion(c) Advantages and disadvantages of using computer networks(d) User ids and passwords(e) Communication media

Learning OutcomesCandidates should be able to:(i) Describe a modem, its purpose and how it is used with analogue telephone lines;(ii) State why it is not necessary to use a modem when using digital telephone lines;(iii) State the difference between analogue data and digital data;(iv) Describe the need for conversion between analogue and digital data;(v) Identify the advantages and disadvantages of using common network environments such as the Internet;(vi) Describe what is meant by the terms user ids and passwords, stating their purpose and use;(vii) Identify a variety of communication media such as fax, e-mail, bulletin boards, and tele/video conferencing.5.1.5 Data: Types and Terminology

(a) Types of data – alphanumeric/text, numeric (real and integer), date, logical/Boolean(b) Definition of file, record, field and key field

Learning OutcomesCandidates should be able to:(i) Identify different data types: logical/Boolean, alphanumeric/text, numeric (real and integer) and date;(ii) Select appropriate data types for a given set of data: logical/Boolean, alphanumeric/text, numeric and date;(iii) describe the terms: file, record, field, and key field.5.1.6 Information Management and Effects of IT: Legal Issues, Implications, Health and Safety

(a) Software copyright(b) Hacking(c) Viruses(d) Social effects of ICT(e) Health(f) Safety

Learning OutcomesCandidates should be able to:(i) describe what is meant by software copyright;(ii) describe what is meant by hacking;(iii) describe what a computer virus is;(iv) explain the measures which must be taken in order to protect against hacking and viruses;(v) describe the changing patterns of employment including areas of work where there

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is increased unemployment;(vi) describe the effects of microprocessor-controlled devices in the home including effects on leisure time, social interaction and the need to leave the home;(vii) describe the use of photo editing software to distort reality;(viii) describe the effects of variation in computer access and ICT skills between different people;(ix) describe the capabilities and limitations of ICT and how communications systems have changed our use of ICT;(x) discuss the issues relating to information found on the Internet, for example unreliability, undesirability and security of data transfer;(xi) describe the potential health problems related to the prolonged use of ICT equipment, for example RSI, back problems, eye problems and some simple strategies for preventing these problems; (xii) describe a range of safety issues related to using computers (electrical, heat, light related) and measures for preventing accidents, particularly in the work place such as not overloading electrical sockets, no trailing wires, no food and drink around the computer,installing fire extinguishers etc.

5.2.1 Word Processing, Desk-top Publishing and Other Presentation Software

(a) Common features of a word processor and desk-top publisher(b) Differences between a word processor and desk-top publisher(c) Basic tasks and uses of word processors and desk-top publishers(d) Use basic features of a variety of different types of software used for presentinginformation in textual, graphical or multimedia format

Learning OutcomesCandidates should be able to:(i) identify the common features found in word processors, desk-top publishers and other presentation software such as left/right/full justification, centering, indentation, emboldening, italics, underlining, copy, cut and paste, bullets, numbering, font selection,point size, font highlight and colour, borders, page and line breaks, columns, tabs, tables, spelling and grammar, word count, inserting pictures and drawing or other objects, grouping, ungrouping, layering, sound effects, animation etc;(ii) identify basic tasks which can be carried out by word processors and desk-top publishers such as letter writing, memos, theses, reports, flyers, brochures, posters, business cards, interactive presentations, web pages etc;(iii) use basic features of word processors, desktop publishers and other presentation software in order to create documents such as letters, posters, leaflets, essays, interactive (multimedia) presentations.

5.2.2 Graphics Production and Image Manipulation

(a) Common features of graphics manipulation software(b) Common features of scanning software(c) Basic tasks and uses of graphics packages

Learning OutcomesCandidates should be able to:(i) identify common features of basic graphics packages, for example: fill, shade, layering, size, orientation, repeating pattern;(ii) identify basic tasks which can be carried out using graphics manipulation packages including changing the look of scanned, drawn or photographed images;(iii) identify the features of scanning software;(iv) use the basic features of a single graphics package to create or modify an image.

5.2.3 Spreadsheets, Modelling and Databases

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(a) Collect/enter data(b) Verification and validation(c) Format data(d) Write rules and formulas(e) Sort and search data(f) Create graphs and charts(g) Features of spreadsheets and databases(h) Typical tasks for spreadsheets and databases(i) Use a spreadsheet for a typical modelling task(j) Use a database for a typical data handling task

Learning OutcomesCandidates should be able to:(i) Design and use a data capture form;(ii) understand the need for validation and verification;(iii) apply the concepts of validation and verification in a practical context;(iv) describe the basic features of spreadsheet software such as cells, rows, columns, replication, formatting, formulae, functions, automatic recalculation, sorting and graph creation;(v) describe the basic features of database software such as fields, records, files, validation, sorting, searching using the Boolean expressions NOT, AND & OR, creation of charts and graphs, different output formats;(vi) describe how a data model may be used for answering ‘what-if’ questions and explain the benefit of being able to answer such questions using a data model;(vii) identify typical tasks for which spreadsheet and other modelling software can be used;(viii) identify typical tasks for which databases can be used;(ix) use software to carry out a task which will allow modification of rules and testing of hypotheses;(x) use data handling software to manipulate and present data

5.2.4 Data Logging and Control Software

(a) Data logging(b) Program instructions(c) Control of devices

Learning OutcomesCandidates should be able to:(i) identify different types of sensor and suitable uses;(ii) identify the advantages and disadvantages of computerized data logging rather than logging data manually;(iii) create instructions to respond to data from sensors;(iv) write a sequence of instructions to control a screen image or external device such as lights, buzzers, sound or turtle, using repeated instructions, procedures and variables as appropriate;(v) identify typical applications involving the use of control and data logging software.

5.2.5 Systems Tasks and Software

(a) Interface software(b) Electronic mail and Internet browsing(c) Saving, copying and troubleshooting(d) Other software tasks(e) Designing, documenting and implementing IT solutions

Learning OutcomesCandidates should be able to:(i) describe the basic features of good interface software;(ii) describe the basic features of an electronic mail package;(iii) use electronic mail facilities, including attaching documents;

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(iv) identify and use basic features of an Internet browser and a variety of CD-ROMs;(v) search for information using key words, including searching the Internet and CD-ROMs;(vi) create, edit, save and copy files on a typical computer system;(vii) carry out basic troubleshooting activities: e.g. solving why a print instruction produced no printout;(viii) identify tasks that may be carried out using other software e.g. using a Computer Aided Design package for designing a house;(ix) write a report detailing how a practical solution implemented on the computer relates to a defined task;(x) document a solution which has been implemented using an appropriate piece of software, for example describing the purpose of the system and how to use it;(xi) produce annotated evidence that a system, which has been implemented, meets user requirements.

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Components of a Computer System

A computer system is made up of Hardware. Hardware is any physical part of the computer you can see or touch.

The main components (parts) of the computer you will need to understand are:

Central Processing Unit (CPU)Arithmetic Logic Unit (ALU)Control UnitMain/Internal memorySecondary/Backing StorageInput DevicesOutput Devices

Task Label the Diagram below;

The CPU is made up of 1.2.3.

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Task Using the text book write a small definition for each part of the computer.

CPU

ALU

Control Unit

Main/Internal Memory

Secondary/Backing Storage

Input Devices

Output Devices

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1. Using the keywords label the diagrams correctly.

Microphone DVD Drive Monitor

Floppy Disk DriveCentral Processing

Unit (CPU)Built in speakers

Mouse Keyboard DVD Drive

Internal Hard disk Spare Bay Processor

Power Supply Unit (PSU)

Expansion CardsSpare Slots for

Expansion Cards

DVD Drive

CPU

Spare slots for expansioncards

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Software

Software' is the term used to describe any kind of computer program or data stored in the computer's memory or as files on storage media. A 'software package' is a collection of programs and supporting data or control files which all work together to perform a specific task, such as a word processor package. (On a CD-ROM the computer files are the software and the disk itself is the hardware.)

There are 4 main types of software used on the computer.System software - The Operating System (OS) of a computer is the complex software that actually controls the input, output and storage devices of the computer, as well as acting as an interface between the user and any other software that is installed.Application Software - Application programs or packages (groups of programs) are designed to enable the computer to tackle a specific task, such as writing a letter.Communication Software - Specialist programs that allow your computer to communicate with another computer or device. Usually extra hardware such as a network card or a modem is neededOther Software – Special programs that are designed to perform specific tasks such as Games, Multimedia Information, Control, Computer Aided Learning (CAL) and Expert Systems for modelling.

TASK Using the computer in school make a list of examples of each type of software - there are at least two examples of each

System Software

Application Software

Communication Software

Other Software

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WARNING – for the exam you will need to know the TYPE of software and not the brand name – ie Spreadsheet, NOT Excel.

TASK – For the following situations advise which type of software you would use.

Typing a letter

Creating a graph

Keeping a list of telephone numbers

Creating a poster

Creating an original image

Editing a digital photograph

Comparing which mobile phone tariff is the best for you.

reading a webpage on the Internet

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Types of Computers

Super computers - these are the fastest and the most expensive computers available and could cost over 100 million pounds. They are mainly used for advanced scientific research, weather forecasting or advanced engineering applications.

Main-frame computers - these are capable of processing and storing huge amounts of data. They would be used by large utility companies such as gas suppliers as well as banks etc.

Minicomputers - these may be used by smaller businesses to manage their data processing or to run something like a city traffic control system.

Microcomputers - these systems such as typically used by home and school users. They can be divided into different types:

Desk top computers - these would typically be supplied with the computer itself (complete with hard disk drive and floppy disk drive) and peripherals such as a screen, a mouse, a keyboard and a CD or DVD drive. Advantages: Relatively cheap and easy to add expansion cards to. Disadvantages: Can take up a lot of space and are not easily moved.

Notebooks (laptops) - these are small (typically 30cm x 20cm), light and easy to carry. The screen is on the inside top flap which hinges open to show the keyboard and mouse controls. They are designed to run on rechargeable batteries or the mains and can contain many of the features available on a desktop computer. Touch pads or a button are usually used to control the screen pointer. Advantages: Portable due to their size and ability to run on batteries.

Disadvantages: Expensive for their processing power compared to desktop computers. You cannot use standard expansion cards. Keyboards and screens not as good for extended usage.

Palm-tops & PDAs (personal digital assistants) - These are small hand-held computers. They are usually supplied with software such as a diary, a contacts database, and some form of word processor. Many now have email facilities and even spreadsheets and databases. They either use a small keyboard or a touch-sensitive screen and handwriting recognition software. They can be linked to larger computers directly by cable or through a docking station or using an infra-red link. Advantages: Very portable. Disadvantages: Relatively expensive, limited expansion, non-keyboard versions can be slow to input data.

Embedded computers - A vast number of modern devices contain some form of built-in computer. Examples include: washing machines; camera, hi-fi systems; telephones; microwave ovens; missiles etc. etc.  The inputs are usually sensors so a keyboard may not be needed. The outputs are usually simple displays or motors and relays to control something

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Table 1.1 taken from ICT for GCSE text book

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TASK1. Arrange the following statements into the advantages or

disadvantages of the different computers. (some of the statements can be used for more than one type of computer)

1. Can use many different types of software

2. Can only use very limited software such as email or diary events

3. Portable

4. Light to carry 5. Fits in your pocket 6. Around £10007.Around £1500 - £2000 to buy

8.Can easily be broken 9.Easy to upgrade or expand

10.Cannot upgrade 11.Very difficult to expand 12.Easy to steal13.No mouse but touch-pad or button control

14.Stylus control 15.Mouse control

16.Ergonomically designed 17.Uncomfortable to use for long periods of time

18.Can run on electricity or battery

19.Standard equipment for businesses, schools and home

20.Not as powerful as a desk-top PC

21.Very strong

22.Around £500 to buy 23. No keyboard – handwriting recognition used

24. Difficult to move around

Desk-Top PC Notebook PDAAds Disads Ads Disads Ads Disads

1 24

2. What does the term PDA mean and what other phrase is used to describe similar types of computers?

3. Imagine you have an older friend who is moving away to University soon. They want to buy a new computer to take with them – remembering of course that they must come home for every holiday. Which type of computer would you suggest – explain fully your answer – why would you suggest that type? (There is no right or wrong answer here as long as you explain fully!)

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Input Devices

The mouse is used to control the movement of a pointer on the screen when it is moved horizontally over a flat surface. A ball under the mouse rotates when it is moved and turns two rods, one for left/right and one for up/down. Buttons on the mouse let you select options from menus and drag objects around the screen etc. Some models are now wireless.

A tracker ball is used in the same way as a mouse but it is useful where desk space is limited. It is like an upside down mouse because the user rotates the ball and the main body part stays still. It has buttons like a standard mouse.

The standard QWERTY keyboard is the commonest way to enter text and numerical data into a computer. Each individual key is a switch, which when pressed, sends a digital code to the computer. For example, pressing the 'A' key produces the binary code 01100001 representing the lower case letter 'a'. Holding down the shift key at the same time produces the binary code 01000001 representing the upper case letter 'A'.

The Specialist Keyboard – Concept Keyboard. These are sometimes called membrane or overlay keyboards.  They are used where it fast input is needed and are ideally suited to selecting from a limited range of choices. You simply touch the image on the keyboard overlay to make a selection and the computer is programmed to respond correctly.

Another specialist keyboard is the Braille Keyboard. The Braille alphabet is made up of patterns of raised dots and the keys of this keyboard are marked with these raised dots as an aid for the blind.

Digital Cameras. These are used to take photographs like a normal camera but produce digital images instead of using film. The light passing through the lens is digitised by special light sensitive sensors. The image is stored on memory chips in the camera and can then be transferred to a computer.

The resolution of such cameras is increasing rapidly and professional models have become standard in photo-journalism. Images are usually compressed as jpeg's to save memory. Advanced models have removable memory cards to increase the camera's storage capacity. Images can be transferred to a computer by cables or memory card readers.

Scanner These are used to digitise images of pages or objects. A light moves slowly over the surface of the picture or object to be scanned. The colours of the reflected light are detected and digitised to build up a digital image. The digital data can then be saved by a computer as an image file. They can be used with OCR software to convert images of text into actual text data which

can be edited by a word processor.

Magnetic Stripe Reader. Magnetic stripes are thin strips of magnetic tape which are usually found on the back of plastic credit and debit cards. When the card is inserted into a reader (in an Automatic Teller Machine or ATM for example) the tapes slides past a playback head similar to that used in a tape recorder. This reads the data from the stripe and passes it to a computer.

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Joysticks are usually used for playing computer games. They input directional data like a mouse but work by switches being closed as the joystick is moved left or right and up or down.Further switches are controlled by buttons such as the 'fire' button.

Microphone. This is used for the input of sound which is then digitised by the computer. Voice recognition software can be used to convert your voice into text or to control menu options.

A video digitiser is used to convert analogue signals from a video camera or video cassette recorder into a digital format. The digitised video data can then be saved as a file or played on the screen. Software will allow the video to be edited and special effects added, as well as individual still images to be captured and saved. Digital video cameras digitise the image inside the camera and save the video frames in a digital format. This data can then be transferred directly to the computer via a fast transfer cable and interface such as firewire.

MIDI Instruments. These are used to produce music and are normal musical instruments which have a midi port for input into a midi interface in the computer. They often have a wide range of special effects or stored sound data from real instruments.

Specialised software allows the digitised music data to be stored as a file, displayed on screen and edited ready for playback.

Sensors. These detect changes in the physical or chemical environment and convert them into electrical signals. These signals can then be digitised and used by the computer.  There are a huge range of possible sensors and they include: heat; light; sound; movement; magnetism; pressure; strain; acidity (pH); oxygen levels; liquid levels; humidity; pulse rates; salinity; water flow; speed and acceleration. Switch sensors can detect angles of tilt or whether something

is open or closed. Sensors are often used when data logging.

Remote Control. This emits a beam of infra-red light which carries digital data signals. They are often used to control TV's and VCR's.  More advanced models can be programmed to transmit a series of commands with one button press.  

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TASK Using the text book or website, make a list of advantages and disadvantages of the input devices.

Device Advantage Disadvantage

Mouse

Tracker Ball

Qwerty Keyboard

Concept Keyboard

Digital Camera

Scanner

Magnetic Stripe Reader

Remote Control

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Output DevicesThe computer monitor, screen or VDU (Visual Display Unit) is the most common output device.

Screen sizes are measured diagonally and are still quoted in inches. Popular sizes are 15 inches (38 cm) and 17 inches (43 cm). Larger monitors make working at a computer easier on the eyes and are essential for use in DTP (desktop publishing) and CAD work. 

Cathode ray tubes (CRTs): Most computer monitors are similar in many ways to a television. They use cathode ray tubes (CRTs) containing an electron gun at the back of the tube which fires electrons at groups of phosphor dots coating the inside of the screen. When the electrons strike the phosphor dots they glow to give the colours.  On a colour monitor each group of phosphor dots is made up of one green, one blue and one red dot (RGB). By varying the brightness of each of these primary colours, the whole group will appear to the human eye as any colour possible. One group of dots is called a pixel (short for picture element).

Liquid crystal displays (LCDs) - these use tiny crystals which, when a charge is applied across them, polarise the light passing through them. Used in combination with special filters, this means that light will not pass through when an electrical charge is applied. LCDs are also used in watches and calculators. They use much less power than a normal monitor and are also used in watches and calculators.

Thin film transistors (TFTs)  - this is a more advanced type of display, giving full colour and high quality output. Each pixel on the screen is controlled by its own transistor and this provides a higher resolution and more contrast.

Field emission displays (FEDs) are used in the more modern flat-panel displays. They use two thin sheets of glass a millimetre apart, separated by a vacuum. The back glass is made up of millions of tiny tips that can be switched on and off and fire electrons at the front screen across the vacuum. When the phosphor dots are hit by the electrons, they glow to produce bright, sharp images.

Speakers: These can play music by the computer from programs or from CD-ROMs as well as spoken output. This is particularly useful for blind users where text or figures can be spoken by the computer. Speech synthesis is used by BT for their directory enquiries service. When the operator has located the number for you the information is given to you through a

computer-synthesised voice. The telephone numbers are stored in a database and the computer reads out the number selected by the operator in the form "The number you require is...".

Lights: These use too much current to be powered directly by a computer but they can easily be switched on using a relay switch. Light-emitting diode (LED) - small low power devices which emit light. Used to indicate various events such as 'power on' or 'hard disk in operation' and to monitor other control applications. Today's LEDs can be found in just about every color of the rainbow and in the invisible regions at each end too. They even come in white, plus they last 100,000 hours or more before they need to be replaced! They can be bright enough to illuminate an entire room, and are no longer just a dim red light on a stereo.

Relay switches & motors: A computer can be programmed to turn relay switches on and off at the required times. For example to control traffic lights or electric motors in a robot arm. Motors are used in the automobile industry to control robot arms that spray body shells or assemble and weld parts together or assemble delicate

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electronic components on a printed-circuit board for computers, radios and almost anything else you can think of.

TASK Using the text book or website, make a list of advantages and disadvantages of the output devices and where you could use them.

Device Use Advantage Disadvantage

CRT

LCD

Speaker

Light

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PrintersDot-Matrix printer: How it works: This has a print head that travels across the paper. The head has a set of pins which are pushed out to form the shape of each character. The pins hit an ink ribbon against the paper as the print head moves along.

Uses: Limited to situations where carbon copies are needed and the quality is not too important. Typical uses might be in warehouses where duplicate copies of orders need to be produced quickly and cheaply.

Ink-jet printers:How it works: The print head contains tiny nozzles through which different coloured inks can be sprayed onto the paper to form the characters or the graphic images. The ink is forced out by heat or by tiny piezoelectric crystals which change shape when an electric current is applied across them.

Uses: A popular choice for home and school use where small amounts of printing are done and colour printing is only occasionally needed.

Laser printers:How it works: These print in the same way as photocopiers. The powdered ink (toner), is transferred to the paper and then fixed by heat and pressure. A school or business printer would have a typical speed of 10 to 20 pages per minute (ppm).

Uses: Common wherever fast, high quality printing is required.

Graphics plotter - the flat-bed plotter uses high precision motors to draw on paper with coloured ink pens. The motors move an arm across the paper in the ‘x’ direction and a pen unit up and down the arm in the ‘y’ direction. An electromagnet lifts and drops the pen onto the paper.Plotters are often used in science and engineering applications for drawing building plans, printed circuit boards and machine parts. They are fast and accurate but relatively expensive compared to printers. They can produce far larger printouts than standard printers, up to the size of a small room.Braille printer - by converting text into the Braille code, this printer produces patterns of raised dots on paper for use by the blind.

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TASK Using the text book or internet, make a list of the advantages and disadvantages for each of the printers (including the cost of purchase as well as running cost)

Printer Advantages Disadvantages

Dot Matrix

Inkjet

Laser

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Storage DevicesMain/Internal Memory

All computers have main/internal memory to store programs and data while the computer is running. This memory is in the form of memory chips and the contents are lost when the computer is switched off (it is also know as 'volatile' memory).

Comparing internal memory with backing storage:It is always faster to access data from internal memory than from backing storage. Data stored in internal memory is lost when the computer is turned off but data stored in backing storage is retained. When programs are run or data files are loaded the contents are copied from the backing storage to the internal memory of the computer. Internal memory is much smaller than backing storage. It is far too small to hold all the data/programs that would be on the backing storage of a typical computer.

How memory works:Programs and data files are stored as binary numbers.  This is made up of just 0's or 1's unlike decimal numbers (0-9).To store the 0's and 1's while the computer is running you need a memory chip. This is made up of millions of tiny switches called transistors. They can store a 0 or a 1 by the 'switch' being either open or closed. This 0 or 1 is the simplest unit of memory and is called a ‘bit’ (Binary Digit). Bits are arranged in units of eight to make a byte. A byte can therefore store eight 0's or 1's in 256 different combinations.  (00101011 and 01110110 would be just 2 possible combinations for example).

One byte is a very small amount of storage and it is more usual to refer to kilobytes (KB), megabytes (MB) and gigabytes (GB).

1 KB = 1024 bytes (approximately 1 thousand bytes) 1 MB = 1024 KB (approximately 1 million bytes) 1 GB = 1024 MB (approximately 1 thousand million bytes)

 4 KB of memory could store roughly one full A4 page of text. 600 MB (on a CD-ROM) could store roughly the text contents of a 10 volume encyclopedia.

Encoding Data:Memory chips can only store binary numbers so other data such as sounds, images or text for example have to be encoded into binary (digitised). If you want to store a character from the keyboard the computer gives it a number code made up of eight bits (1 byte). These text codes are the same internationally and are called the ASCII code (American Standard Code for Information Interchange). The code for the letter ‘a’ is 01100001 and one byte of memory is therefore used to store the letter 'a' (in code) on a memory chip.

Remember - since computers can only store binary numbers, all computer data has to be in this digital format. Images, sounds, video etc. all have to be digitised before they can be processed by a computer.

Backing storage: Backing storage (also known as secondary storage) means data storage that retains its contents when the computer is switched off.  It can be used to hold both programs and data.

It is always faster to access data from internal memory than from backing storage. Data stored in main/internal memory is lost when the computer is turned off but data stored in backing storage is retained.

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When the user wants to access the data from backing storage it is copied to the main/internal memory of the computer. Common backing storage media:

Hard disks:The hard disk is usually the usual main backing storage media for a typical computer or server. The operating system (e.g. Microsoft®

Windows), applications software (e.g. word-processor, database, spreadsheet, etc.), and any program data would all be stored on a hard disk. A typical home/school microcomputer would have a disk capacity of 20 or 30 gigabytes.

Floppy disk drives:These can be found on most microcomputers and accept the usual 3.5 inch floppy disks. High density disks for a PC hold 1.44 MB of data (enough to store about 350 pages of A4 text). A floppy disk needs to be formatted before it can be used but most disks are now sold already formatted for PC's. Floppy disks are useful for transferring data between computers and for keeping a back-up of small files.

Tape: Magnetic tape can be used for permanent storage. Tapes are often used to make a copy of hard disks for back-up (security) reasons. This is automatically done overnight on the Whitefield network and the tapes are kept in a safe place away from the computer. 

CD-ROM (Compact disk): CD-ROM's hold large quantities of data (650 MB) in the form of programs, text, sound, still pictures and video clips. They are also known as optical disks because the data is read by a laser beam reflecting or

not reflecting from the disk surface.

CD-ROM's - ROM means Read Only Memory and this means you can only read from the disc, not write or store data onto it. This is the most common sort of CD available and is the way most software programs are now sold. Like a floppy disk, a CD-ROM only starts spinning when requested and it has to spin up to the correct speed each time it is accessed. It is much faster to access than a floppy but it is currently slower than a hard disk (a modern 40x speed CD-ROM drive is 40 times faster than the 15 KB per second of the original single-speed CD-ROM's).

DVDs - "Digital Versatile Disk." (Formerly Digital Video Disk.) Same size as a CD but stores seven times CD capacity on a single side. DVDs can also be double-sided or dual layer. Today most DVDs are used to display full-length commercial motion pictures, plus additional material such as outtakes, director's notes, movie trailers, etc. Single sided DVDs can store 4.7GB for single layer and 8.5GB for dual-layer disks. Double sided DVDs can store 9.4GB for single layer and 17GB for dual-layer disks.

Keydrive: -A keydrive is a small removable data storage device that uses flash memory and a USB connector. Keydrives are also known as keychain drive, micro hard drive, pen drive, pocket drive, thumb drive, jump drive, USB flash drive, USB flash memory drive, USB key, USB memory key, USB stick, They range in size from 56Mb to 1GBUSB ports are much more common than CD and especially DVD burners, so your USB flash drive will work with more computers than a CD-R or DVD-R. Also, the process of uploading files from your computer to a USB flash drive is much faster and simpler than burning a CD or DVD. Additionally, USB flash drives act like portable hard drives to which you can add and delete files as many times as you like. With CD-Rs and DVD-Rs, you can only add data once, and you can't remove data once it's burned onto the disc.

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TASK http://www.waingels.wokingham.sch.uk/Departments/IT/Resources/StorageMedia2001.doc

1 Give two ways in which a CD-ROM disc is different from a floppy disc. [2]

2 A pupil is researching material for a school project. The pupil has a computer which has a CD-ROM drive and access to the Internet. [2]

Give one advantage of using the Internet rather than a CD-ROM.

Give one advantage of using a CD-ROM rather than the Internet.

3 Describe three steps a student will take to find and obtain a picture from the Internet. [3]

4 A company is developing a piece of multimedia language software for use in a school. Give two reasons why the company decides to issue the software on CD-ROM and not on floppy discs. [2]

5 A newspaper needs some pictures to insert onto the front page. Give three ways you can use Information Technology to obtain the pictures in electronic form.

[3]

6 Give one reason why a digital camera is suitable for obtaining pictures for a multimedia presentation. [2]

7 Give one reason why you would not edit a large movie file on a CD-ROM.

8 A company is developing a piece of multimedia language software for use in a school. [2]

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Give two reasons why the company decides to issue the software on CD-ROM and not on floppy discs.

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Protecting Data

The risks to data:The data stored in a computer can often be far more valuable than the actual computer equipment. Losing such data could put a company out of business.

Examples of valuable data are: a company’s financial records; customers’ details; stock records; data collected from experiments. 

Data can be damaged or destroyed in the following ways: mistakes by users such as deleting files hackers gaining access to systems and changing or deleting data computer fraud where data is changed to benefit individuals theft of computer equipment with data on its hard disk(s) infection of systems and data by computer viruses. deliberate and malicious damage by users of the system disasters such as fire, floods, earthquakes etc. destroying equipment breakdown of hardware, particularly disk drives

Reducing the risks of data loss: Making a backup of data: Making a backup of valuable data is an obvious way of reducing the damage

caused when the original data is lost or damaged. Making a backup should be a regular occurrence and ideally the backup data

should be securely stored well away from the original data.

Examples: Individuals: For pupils working on a stand-alone computer, simply making a backup copy of their files on the hard disk will reduce the risk of losing data. They could also save a copy to a floppy disk if the file was small enough or store larger volumes on a CD-ROM using a CD writer.

Schools: A back-up of the whole Whitefield school system is carried out automatically every weekday night so the most that can be lost is one day’s work. Special tape drives save the data onto magnetic tape cassettes capable of holding over 20 GB of data. This is enough capacity to allow all the data on the server’s hard drives to be backed up. A number of tapes are used in rotation and previous back-up copy is taken away from the school premises each night in case of a disaster such as a fire. Tapes kept on-site should be stored in a fireproof safe.

Businesses: Larger companies may have several sites with secure Internet links between them. Each site can be used to store backups of the data stored at the other sites. Some businesses have contracts with a company that specialises in data backup and they will back up all the data at a secure remote location using a secure Internet link.

Keeping hardware secure:Protect the computer itself by using locks on doors and windows and using security bolts to fix the computer permanently to the desktop. Floppy disks are easily physically damaged and must also be kept away from magnetic fields and dust.

Illegal access to computers:

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Hacking involves breaking codes and passwords to gain unauthorised entry to computer systems. Once into a computer system a hacker can do an enormous amount of damage. Stand-alone computers are usually safe as there is no connection for the hackers to break into. Computers which form part of networks or those with external links, such as attached modems, are in danger from hackers.

Ways to restrict access: User Ids (user identification) and passwords – each user must enter a

unique username and a password to access either a computer or their own area on a server.

The password is a secret combination of letters and/or numbers to prevent anyone else accessing the computer system with their username.

Passwords should have at least six characters and you should use passwords that have no meaning so they would be hard to guess.

Usernames can be used to restrict access to certain parts of the system so they cannot delete or install programs/files or change the computer setup.

Protecting passwords – to protect your password the system should: force you to change passwords regularly (the longer you use a particular

password, the more likely it is that it may be discovered). have an automatic lockout if a password is wrongly entered more than three

times. This may prevent access by password guessing software.

Blocking external access – external hackers can be blocked by disconnecting modems from the telephone line when not being used. Systems with permanent phone connections need special software called a ‘firewall’ to prevent unauthorised access.

Computer viruses:A Computer virus is a program which can be introduced into a computer via a floppy disk, email attachment or the Internet. A virus program contains instructions that make it attach itself to system files or programs and make copies of itself. It can therefore spread to other programs on your hard disk and onto floppy disks or email itself to all the contacts in your email address book.

Their effects can be devastating and cost millions of pounds to fix. They can alter the host program, stop it working completely or cause a whole hard disk to become scrambled.

Protecting against computer viruses:Anti-virus software is usually required to detect and then destroy them but it is important to have regular updates to deal with new viruses. The anti-virus software scans the computer’s disks looking for any viruses which it then removes and alerts the user.Protecting floppy disks – The ‘write-protection’ hole in the corner of the floppy disk can be kept covered to prevent accidental wiping of the disk or the introduction of viruses.

To reduce the risk: Never use a floppy disk given to you from an untrustworthy source or pass

floppy disks around between your friends. Do not start up a computer with a floppy disk left in the drive. Set the computer BIOS so the boot sequence so it does not start with the floppy

disk drive. Keep the write-protection hole covered on floppy disks that are used to store

original “clean” programs – so they can be reinstalled with confidence. Never open an email attachment that comes from someone unknown or is not

clearly explained in the email message. Install a virus protection program and keep it up-to-date!

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Task Using your notes complete the following past exam questions.

Suggest two rules for choosing a password[2]

State two things that need to be done to keep a password safe [2]

1.

2.

1.

2.

A mail order company keeps its data on a computer system. The company is concerned about hacking.

a) Describe what is meant by hacking [1]

b) Describe two possible effects of hacking for the mail order company [2]

a.

b. 1.

b. 2.

At the end of each day, a company makes a backup of its data. What is a ‘BACKUP’?[1]

Users of a school network are required to enter a user name and a password into a log on window.

a) what is the purpose of the user name? [1]]

b) what is the purpose of the password? [1]

a)

b)

Describe what a computer virus is. [1]

Describe two ways of reducing the risk of a computer virus infecting a computer[2]

1.

2.

State two ways of preventing other people copying your computer files[2]

1.

2.

State two ways, other than copying, in which people could interfere with computer data belonging to someone else.[2]

1.

2.

Design a poster to advertise to students how they should choose a password and why they should keep it secret – attach the printout to this page.

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Communication – Modems & Digital Networks

Communication between computers:For a computer to communicate with another computer (which may be a completely different system) an interface is needed.Digital data is easier to communicate between computers because it is already in a format that can be processed.

The need for conversion between analogue and digital data:A computer cannot process analogue data. Analogue data must be converted into digital data by the interface. This is called digitising the data. An example of an analogue signal is the audio tones that travel along telephone cables. An interface is usually an interface card and it is inserted in one of the slots provided inside the computer. It could also be an external device plugged into one of the computer’s communication ports with its own power supply.

Examples of interfaces:Modem (MODulator – DEModulator):

The purpose of a modem is to convert between the analogue signals used in telephone cables and the digital signals used by a computer. A modem will therefore be needed if a computer needs to access the Internet, email, video-conferencing or fax communications. A modem works as an input and an output device because for incoming signals it converts the analogue signal into a digital signal and it works in the reverse way for outgoing signals.

A modem transmitting and receiving at a speed of 33,600 bps (bits per second) can communicate about one page of text every second (4200 bytes or characters a second).

Sound Card:A sound card is needed to output for music or speech from programs, CD-ROMs, and input analogue sound signals from a microphone. It can include a MIDI (Musical Instrument Digital Interface) which is needed to connect musical instruments to a computer.

Network card:A network card lets computers communicate with other computers that are networked together. A cable is plugged into the card and each computer then has access to any shared programs, devices and files on other computers or a main server computer, as well as shared printing.

Digital phone lines:It is not necessary to use a modem when using a digital telephone line such as an ISDN (Integrated Services Digital Network) line to connect a computer (or a LAN) to the internet because the signal is already a digital one which a computer can process.

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Communication MediaIntroduction

Information Technology has had a big impact on the way we communicate. We are now able to chat and play games with people across the globe. We can send messages and faxes which can arrive almost instantly at their destination, thousands of miles away. We are able to buy goods from almost anywhere in the world and have them delivered to our door. IT has made the world seem smaller and the community in which we live larger.

TeletextTeletext enables text and simple pictures to be sent along with the television picture. This enables information about news, weather, sport, travel and local information like cinema listings to be accessible easily. The amount of information which can be sent along with the TV picture is limited, so the pages are very simple and are at a low resolution. To have high resolution teletext pages would need more information to be passed on. With the advent of Digital Television, this is possible and a whole host of high definition teletext pages are available.

FaxesFax machines scan paper documents and converts them into a digital format. The fax machine then converts the digital image to an analogue signal which can be transmitted over a telephone line. A receiving fax machine translates the analogue signal back into a digital one and then prints the image onto paper to create a copy of the original document. A fax machine is a little like having a photocopier with the copy appearing out of a different machine, possibly thousands of miles away.

The InternetThe Internet is a term given to encompass a number of technologies which take advantage of the global telecommunications network. Computer networks from universities, government organisations and businesses all over the world are linked together using telephone lines to transmit data between the networks. In this way information can be shared with people all over the world.

Most people get access to the Internet by phoning their Internet Service Provider (ISP) using a modem. A modem translates the digital language of the computer into analogue sounds which can be sent down the telephone line. A modem at the other end of the line translates the sounds back into a digital message the computer at the other end can understand. The ISP allows the user to get access to the Internet and all the services it provides.

E-mailE-mail, or electronic mail, enables people to send message s from one computer to another across a network. This network could be the Internet and so messages can be sent all over the world.To send an e-mail the user types a message and addresses it to an e-mail address. The message is then sent to the mail server of the recipient. On this server is the recipients’ mailbox where all messages are stored until they are downloaded onto the recipients’ computer.Along with text messages computer files can be sent as attachments. In this way documents written in word processors or pictures scanned into the computer can be sent with an e-mail.Received e-mail's can be read, saved or deleted. Most e-mail programs also allow the recipient to easily reply to a message by hitting the reply icon. This reply includes the original message so the sender can be reminded of what they said in the original message. Messages can be forwarded on to other people, so the same message can be passed on.E-mail's can also be sent to multiple e-mail addresses in one go. In this way many people can receive the same message without the sender having to write the message out repeatedly.

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E-mail's can get to their destination almost instantly, so it can be a very fast way to communicate. Some people however get so many e-mail's every day that they cannot possible read them all.

VideoconferencingVideoconferencing is the use of video camera's and microphone to send video signals to other computers in real-time. This means that two people who are Videoconferencing could see one another and talk to each other as if they were in the same place, even though they may be miles apart.

The advantages of Videoconferencing are: -

Being able to see people in person can have advantages over e-mail.

The response to questions can be instant.

The users can draw pictures on a white board on the computer to help explain things.

It is more personal than a text message.

Many people can get involved in the discussions so that meetings could take place without the need to travel to one place to hold the meeting.

Videoconferencing can be used in schools to have remote learning where the numbers of people taking a particular course may be too small to make it viable. By joining together with other schools minority subjects can become possible.

The disadvantages of Videoconferencing are: The computer running the software and hardware needs to be very fast. This

means that it is also very expensive. Special telephone lines called ISDN lines are needed to be able to send the vast

amounts of data the video images involves. It is no substitute for meeting people in person.

E-commerce

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There are many commercial web sites around today which either sell services (such as information) or products. These are bought 'online' using credit cards. To make sure that fraud is reduced these web sites code information like credit card details before they are sent to the web site. While this helps make transactions secure, criminals are always trying to overcome this security. Buying things online from reputable companies however is just as safe as buying things using a credit card in a restaurant or shop.

Many businesses are able to sell products cheaper over the Internet as it cuts down the need to have an attractive shop. Businesses can also sell their products to a wider market. Businesses which produce things for a specialised market may not sell many items if they opened a shop in a city. On the Internet however, because the market is a global one, many products can be sold even if they are specialised.

Buying things online also suits many people with busy lives who don't have time to wander around the shops looking for what they want. Some supermarkets even offer shopping online and deliver the weekly shop without the user from having to go near a supermarket.

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TASKQuestion Answer

What is the word “Modem” short for?

Describe what job a modem has in helping you communicate information.

How would you describe the difference between analogue and digital data?

Why do you have to convert data between digital and analogue format?

List the 4 main types of

communication media

Give one advantage of the media

Give one disadvantage of the

media

1

2

3

4

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Computer NetworksWhat a network is:A computer network is developed by linking computer systems together. The network includes the computer systems, the connections and the hardware needed to allow the communication.

Networks can be limited to a building/area (a Local Area Network or LAN) or worldwide such as the Internet (a Wide Area Network or WAN)

The advantages of networking: Computers can communicate with each other and share data and files. Computing power and/or storage facilities can be shared. Hardware such as printers can be shared. There is control over which programs and settings a user has access to.

The disadvantages of networking: A virus can spread more easily. If a virus gets into one computer, it is likely to

spread quickly across the network because they are linked. As data is shared there is a greater need for security. Users of the network have

to have user ids and passwords. If the server fails, all the workstations are affected. Work stored on shared hard

disk drives will not be accessible and it will not be possible to use network printers either.

The cost of installing the equipment is greater. Cabling can be expensive to buy and to install.

Damage to cables can isolate computers. Some sections of the network can become isolated and will not be able to communicate with the rest of the network.

Because networks can be complicated to maintain, a network manager may be needed to run the system.

Common Network Environments:

An intranet:An intranet is provides information on web pages but the information can only be accessed from the local network.

Advantages: An Intranet is free because it does not involve phone links. Information can be easily updated and shared inside a company or school. The web pages can be viewed using a standard web page browser. More of the information will be useful because it was created for particular

users.  Disadvantages:

Information cannot be shared outside the local network.

The Internet:The Internet is a world-wide network of linked computers sharing a vast amount of information.

Advantages: Millions of people contribute information. Data can be rapidly added and updated to reach a huge audience. It can be used to sell goods to a world-wide market.

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Disadvantages: There is a lot of useless information, much of which is out of data and it can be

very difficult to find what you want. Much of the information is misleading or has not been checked for accuracy. It is not regulated and offensive and illegal material exists. Issues such as security become even more important as potential hackers could

possibly be trying to break into a computer system from anywhere in the world

TASK

From using your notes answer the following questions: -

1. What do the terms LAN & WAN mean?

LAN…………………………………………………………………….

WAN……………………………………………………………………

2. How are computers connected together to form a LAN network?

3. In school we use a LAN network – how many printers do we need to have in each room?

4. When you log on to the computer your logon tells the computer who you are – what else will your logon tell the computer (think about your access on the computer)?

5. There are many disadvantages to using a LAN network – however we still choose to use it in school – Explain why you think this is?

6. What is the difference between an Intranet and the Internet?

7. Explain what you think is the biggest disadvantage of the Internet? Write your answer in full – giving an example.

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8. What does the term “user id” mean in full?

9. What 3 things must you do to ensure the security of your data?

10. Imagine you have been asked to give a talk to the Year 7s about the problems of using the school network. One pupil asks you why they have to use passwords all the time. Explain to the pupil why we use passwords and what they should do to make sure they keep their password safe and secure. (read the notes for help)

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DatabasesA computerised database stores data in one or more organised tables. Because the data is stored in named fields it has a context so it becomes information. Database software is designed to make it easy and efficient to store, edit, sort and search information.

Database terminology:Field - a field is used to store an individual item of data.Example: typical fields might be 'surname', 'colour', 'height', 'DOB' etc. Key Field - a field that is unique for each record in the database and can therefore be used to identify just that record.Example: A field like 'surname' would not make a good key field because two records in a database of people could easily have the same surname.

Record - a record is a group of related fields.Example: In a database of doctor's patients, each patient would be a separate record, with fields for 'surname', 'DOB', 'address', 'allergies' etc.

File - a file is the group of records that make up the database.

Examples of use:Whitefield school has a database with all the pupil details on it.The whole database is a file. Each pupil is a separate record in the file Each record is made up of fields such as 'first name', 'surname', 'DOB', 'tutor group', 'emergency contact number', 'tutor group' etc. The key field is the unique 'admin number' given to each pupil when they join the school.

Data Types:When a database is designed, all the fields are set to accept a particular data type. This helps check for the wrong type of data being entered and makes sure the data is stored as efficiently as possible. It also means it will be sorted correctly.

Alphanumeric/text - a field of this data type will accept both numbers and text. When to use - if you want to enter text or a mixture of text and numbers. When NOT to use - if you want to store only numbers or only dates. You can enter numbers or dates into text fields but they would get sorted as if they were words and could not easily be used for any calculations.

Numeric - a field of this data type is used to store numbers. There are two types of numeric field you need to know about:

Real - used for decimal numbers such as 3.4, 3.1427 and 6.0 etc. Real numbers can be formatted as currency (i.e. £5.67) or to a fixed number of decimal places (i.e. entering 3.1427 into a real number field formatted to two decimal places would mean it appeared as 3.14)When to use - if the field is going to be used to store numbers with decimal places such as 'height', 'length' etc.

Integer - used for whole numbers.When to use - if the field is only going to be used to store whole numbers, i.e. 'number of children', 'car doors' etc.

Logical/Boolean - a field of this data type will only let you enter a 'Yes' or a 'No'. This may be as text (YES/NO or TRUE/FALSE) or as a tick/blank.When to use - when you only need to store something as 'true' or 'false' or store whether something exists or does not exist.

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Date - this special field stores days, months and years so that records can be sorted correctly. Date fields can display the date information in different formats such as the full name of the day/month (28th August 1961) or the numerical versions (28/08/61)When to use - for any field which will be used to store date information.

Examples of use:A football club uses a database to store details of its players.

Data such as Surname and First name is stored in text fields. The players car registration is mixture of text and numbers so it is stored in a

text field. The height of the player (in metres) is a decimal number so it is stored in a real

number field. The number of goals scored is a whole number so it is stored in an integer

number field. The player's date of birth (DOB) is a date so it is stored in a date field. The players telephone number has a space between the code and the actual

number so it is stored in a text field. Information such whether the player is right or left footed is stored using a

logical/Boolean field. The field is labelled as 'Right footed?' and the entry is either a TICK or left blank.

Examination questions on this topicYou will often get a question about a table from a database. It can be very easy to mix up a question about field names with one about field data types.

For example:

Item Stock code

Size (cm)

Manufacturer

Date purchased

Plastic?

Hose clip T0090 0.90 Fisher 28-07-2002 No

Hose clip T0135 1.35 Fisher 28-07-2002 No

Joining clip K0118 0.90 Asus 28-04-2001 Yes

Extension hose

L0035 100.00 Fisher 28-02-2000 Yes

If you are asked to name a field then look the row at the top which should have all the field names.  In this example, 'Item', 'Stock code' etc. are the field names.

If you are asked to identify the key field then look for a column of numbers or numbers/text that identifies each item uniquely. In this example the 'stock code' is the key field as each item in stock would be given a unique code to avoid confusing it with any other item.

If you are asked to describe a suitable data type for a particular field then you must look at the type of data being stored in each column. If the data is text or a mixture of text & numbers (including spaces or brackets etc.) then the data type would be text.

If the data is numeric then the data type would be numeric but you also need to say if it should be real or integer. (Remember, use real if the data has decimal places and integer when all the data is whole numbers)

If the data is in the form of a date then the data type would be date. It does not matter if the date is stored in a numeric form (i.e. 28-08-61 or 28/8/1961) or written out fully (i.e.28th August 1961).

If the data seems to have only two options, particularly 'yes' or 'no' then the data type should be logical/Boolean.

For the example table above, the field names and data types would be as follows:

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Field name

Item Stock code Size (cm) Manufacturer

Date purchased

Plastic?

Data type

Text Text (key field)

Numeric (real)

Text Date logical/Boolean

TASK complete the following past exam questions

http://www.waingels.wokingham.sch.uk/Departments/IT/Resources/DatabaseApplications2000.doc

1 The school office computer has a database of pupils. [1]

Give one occasion when a pupil’s record will need to be inserted into the database.

2 Data about pupils is stored in a datafile [4]

Give one reason why the date of birth is stored and not the age of a pupil.

Give one reason why each record has a record number.

Give one reason why the data for Male or Female is coded M or F.

Give one reason why the data is validated.

3 A large database is being created [4]

Describe two ways of verifying the data

.

4 When using a software package a four digit number has to be entered. [2]

Describe two validation checks which should be used on the number.

5 Describe what would happen if the number was allowed to be entered incorrectly.[1]

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6 The school office computer has a database of pupils State two ways in which pupil records can be protected from unauthorised access. [2]

The database shows some items of equipment in a science laboratory, their cost and on what shelf they are located.

Item Quantity Cost (p) Shelf

test tube 57 42 A

stand 6 83 B

tripod 14 12 G

bunsen burner 12 240 C

rubber pipes 27 98 G

flask 17 56 B

beaker 18 45 A

jug 9 34 G

thermometer 22 120 D

heat mat 20 79 G

1 Which item or items will be listed if the following search condition is input?Quantity > 20 AND Shelf = “G”

[1]2 Write down a search condition which would find all the items on shelf B which

cost less than 40 pence.[3]

3 Describe the steps which should be taken to produce a printout to check the stock on the shelves.

[2]

4 A school records details of pupils on a computer database. The following data is stored. Surname, Forename, Form, Age, Home address.State one reason why it is not advisable to store a pupil’s age.

[1]

5 State how you would overcome this problem.[2]

6 State why you would use more than one field for storing the home address.[1]

7 The secretary has to type the pupil details into the database. State two ways of verifying the data.

[2]

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8 Give two occasions when a pupil’s record will need to be altered. [2]

9 Employees of a company have to enter 4 figure code numbers into a data handling package.State two validation checks which could be used to check that the validation of the code numbers is working.

[2]

10 If the code number was not validated, incorrect data would be entered into the database causing problems. State one example of such a problem.

[1]

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Validation & VerificationValidation is the name given to the process whereby the information entered in the database is checked to ensure that it makes sense. For example, you can use validation to check that only numbers between 0 and 100 are entered in a percentage field, or only Male or Female is entered in a sex field. It cannot check that it is correct (the process of checking that the data is actually right is called verification).

Obviously it's very important that the information in your database is correct if you're going to get worthwhile results when you search or sort the data. There are various methods that you can use to check your data.

TypeThe use of field types forms a basic type of validation. If you make a particular field numeric (i.e. a number), for example, then it won't let you enter any letters or other non-numeric characters. Be careful when using the numeric types, however - if you use them for things like phone numbers, for example, you won't be able to enter spaces or any other sorts of formatting.

PresenceThis type of validation might go by different names, depending on your database program - sometimes it's called something like Allow Blank or mandatory for example. This type of validation forces the user to enter the data in that field.

If you had an address book, for example, you might know the person's address and not their phone number, or vice-versa, so it wouldn't make sense to make those fields mandatory. On the other hand, it doesn't make sense to have an address book entry with no name, so you should check for the presence of the name.

UniquenessSome database programs allow you to check whether the contents of a particular field are unique. This might be useful to prevent users entering the same information twice. For example, if you were creating a car database, you should make the registration number field unique as no two cars should have the same number.

RangeIf you're using a number field, then you might want to limit the range of inputs. For example, you might want to limit prices in a stock database so that they are all positive, or limit the range of a percentage field so that the values entered are between 0 and 100.

FormatYou might have a field in your database that requires an entry in a particular format. A simple example might be a date, or piece of text of a certain length. More complex examples might include things like postcodes, or National Insurance or driving licence numbers.

Multiple ChoiceA good way to validate fields is to use multiple choice responses. These might take the form of a listbox, combo box, or radio button. For example, you could create a field that would only allow the user to select from Yes or No, or Male or Female.

Verification is used to check that data is entered correctly and that there are no transcription errors.

If data has been copied automatically from one format to another then the computer will automatically compare the two versions and inform the user of are any differences.

If a keyboard operator has done the transcription then this type of check is impossible. In this situation the data is re-entered by a different operator with the computer

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system checking for differences as the second copy is entered. Any differences must be the result of a transcription error by one of the two operators. In this case the transcribed versions can be checked manually against the source document and the error corrected.

You have probably come across another example of verification when setting a new password - you are usually asked to key the password in a second time to ensure that you didn't make a keying error the first time, as it is not echoed on the screen.

The main aim of verification is to trap transcription errors – errors in transferring the source data into the computer.

It cannot guarantee accuracy:- If the original data was incorrect the data will be entered wrongly- If the data was entered twice, it may have been entered twice incorrectly- If the data was being manually checked, mistakes can creep in.

TASK1) If a date is to be input with the month as a number:

a) Give an example of Validation Check that can be used.b) What is the name of this type of check?

2) State which of the following will ensure the INTEGRITY of input data?a) Passwordsb) A Range Checkc) The write tab on a floppy discd) Verificatione) Check Digit

Answer to question 1a)b)

Answer to question 2

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3) Which on the list in question 2 ensures Security of Data?

4) Say whether each of the following is a Type Check, a Length Check or a Range Check:

a) Seeing whether an input item is Numericalb) Checking whether a name is less than 20 charactersc) Checking whether a name contains any digitsd) Checking whether the month of June has 30 days

5) What is being described?a) A digit added to the end of an account number as a checkb) Checking characters are not numericalc) Checking correct number of characters have been inputd) Check that the correct range of values has been usede) Check that data has actually been entered

6) Define the term Data Verification in one sentence

7) Define the term Data Validation in one sentence

Answer to question 3

Answer to question 4a)b)c)d)

Answer to question 5a)b)c)d)e)

Answer to question 6

Answer to question 7

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Software CopyrightThe Copyright, Designs and Patents Act 1988

Copying computer software is a criminal offence. The Act covers stealing software, using illegally copied software and manuals, and running purchased software on more machines than the licence allows.

The legal penalties for breaking the copyright law include unlimited fines and up to two years in prison.

All the software that you use should be fully licenced. When you purchase software you usually are licenced to use it on just one computer. It is illegal to make copies of the software to use on other computers, even if they are your own.

Software licences can be: Single user - licenced for installation on one computer Multi-user - the licence allows you to install the software on a named number of

computers Site-licence - the licence lets you install the software onto an unlimited number

of computers, as long as they are on one distinct site such as a school

Software protection:Software companies try to prevent illegal copying of their disks using the following methods:

Copy protection - the disk (or CD-Rom) may be formatted in a special way so it cannot easily be copied.

Product registration - the software has to be registered with the software company, usually by giving them a unique code that came with the product and in return being given an 'unlock' code.

Restricting the number of installations - each installation is recorded on an installation disk and only a certain number are allowed.

Installation code - the software cannot be installed without a unique code provided with the software.

Encryption - data can be scrambled up and cannot be read without the correct software.

Dongle - some form of hardware, often built into connecting cables, without which the software will not run.

Details of the user are built into the software when it is ordered so it displays the users name as it is used. This does not prevent the copying but it makes is obvious if you are using an illegal copy.

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TASK Complete the following past exam questions.

Question Answer

A company distributes its software on CD-ROM. Describe three ways the company can try to prevent illegal copying of software[3]

1.

2.

3.

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Social Effects of ICT

The rapid rate of change:

As a pupil at school you are used to using computers and may also have a computer at home. You will be aware that computers are used widely in the modern world in places such as shops or businesses.

What you may not know is how very recent the development of computers has actually been. Other major inventions such as cars and airplanes were invented over a hundred years ago, but compared to the changes in computers, they have changed very little.

The first electronic computers were only constructed around 50 years ago and were used during the war to calculate firing tables for field guns and to crack German codes. They used glass tubes called valves and the machines filled large rooms. They consumed huge amounts of electrical power and their processing power was tiny by today’s standards.

The widespread use of computers in homes, schools and businesses only really began about 20 years ago. This growth continues as computers become more sophisticated, with larger memories, better displays, faster processing, new features. However, despite all these improvements, their price remains the same or even falls.

The computer access and skills divide:

Many people thing this is leading to a society that is divided by technology. Those who cannot afford the hardware or lack the confidence are disadvantaged compared to those who embrace each new advance. Not keeping up with technology leads to people being disadvantaged socially, in education and in employment in many ways, some of which are outlined below:

Not being able to access the huge range of information available over the Internet or on CD-Rom and digital television etc.

Not being able to use ICT skills such as using word processing and DTP software.

Not being able to sort, search and analyse data using software such as spreadsheets and databases.

Not being able to use creative tools such as graphics software, CAD and 3D design software, as well as music and video editing software.

Not being able to use more advanced communication methods such as email, news groups, phone texting, video phones, chat rooms, bulletin-boards, telecommunications etc.

Our dependence on technology:

This rapid increase in the use of computers is having an enormous impact on our lives. Our modern way of living simply could not exist if this modern technology were removed.

Examples:

Our financial system is dependant on modern technology to process the millions of cheques written every day.

With modern telecommunications, it would be impossible to control the millions of telephone calls made every day.

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Communication:

Modern communication has become almost instantaneous. Email is cheap and fast and Information and Communication Technology allows documents and diagrams to be faxed around the world. More and more people are now working from home and this is likely to increase as video-conferencing becomes more and more commonplace. In communication technology, there have been huge advances in digital communication through satellite and cable television and digital radio.

The vast quantity of information available through the Internet requires new skills to search out and select the information needed from the various sources and articles.

Mobile phones are now used to communicate via text messages, images and even video as well as being able to access information over the Internet and send/receive email.

Employment:

The introduction of computers has resulted in many changes in employment patterns. Many jobs were lost, particularly from the manufacturing industries, as the repetitive tasks of unskilled workers were replaced by machines.

An example would be the replacement of car body assembly workers and body part painters by robots. However, computerisation has replaced jobs across most areas of the workplace, right up to middle management positions.

There have been positive effects on employment, many new jobs have been created in communication technology and computing, both in the service and manufacturing industries.

Many experts also argue that the increase in jobs in the service sector; shops, hotels, catering and leisure industries is partly due to the increased wealth generated by the more technologically advanced industries.

Advances in ICT have also allowed teleworking to become a significant factor in employment patterns. This involves carrying out work away from the office and communicating with the employer through the use of computer and telecommunications equipment. This has obvious advantages for individuals but society as a whole benefits in terms of reduced commuting and hence savings in costs and pollution, as well as allowing employment to those working in remote areas. 

As a factory invests in computerised equipment some of its workers may be made redundant. Its productivity rises as its labour costs are reduced and it will become more competitive. If it does not invest in computerised equipment then higher labour costs and lower productivity will means its products will be less competitive. This could result in the company failing and jobs being lost anyway. This is the issue that employers, trade unions and governments have to face.

The switch to computerised systems involves considerable retraining and means that a modern society needs to have a more flexible workforce.  Individuals need to understand how computers work and the effects that Information and Communication Technology has on their lives so that they can influence the changes that are taking place and ensure that a better quality of life results from those changes. The rapid advances mean individuals may have to retrain for employment several times during their working lives. 

Data, and what it is used for:

Those who said that the use of computers would lead to the paperless office were sadly wrong. In fact, computers have lead to an increase in the overall amount of

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paper printed. This is partly due to the amount of information about people held on computer files which is then used to generate computerised mail that is delivered to our houses as letters, bills, forms and advertising.

Such data may be highly confidential, for example criminal, medical and financial data. Any errors in this data due to errors in the source of the data or when it is entered can have an issue that may have a huge effect on our lives.

TASKComplete the following past exam paper questions, use your notes and text books

Question Answer

Describe three ways using computers might result in legal or moral problems

[3]

1.

2.

3.

A school decides to place 5 computers for pupil’s use in the school library. Describe how this decision will affect the library staff

[3]

Give two jobs that have been created by the increased use of computers

[2]

Describe two ways the internet has allowed people to trade from home

[2]

A school provides laptop computers for students to borrow and use at home. Describe two ways that this would benefit the students’ work.

[2]

A family has a computer. Give two different benefits to the family of connecting this computer to the internet.

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[2]

Describe how the increased use of credit cards has affected shopping

[3]

A school student is downloading information for use in a project. Discuss the issues relating to information found on the internet.

[7]

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Health & SafetyIt is important to realise that working with computers, particularly for long periods of time, can be dangerous to your health. To create a safe working environment, the following factors should be considered.

Specific Risks:

Repetitive Strain Injury (RSI) - This is caused by repetitive finger movements over long periods of time and can cause serious pain in the finger joints.

Solutions - to reduce the risk of RSI you should:

have your keyboard positioned correctly

use a keyboard with a good ergonomic design

develop a good typing technique

try using wrist supports placed in front of the keyboard

take regular breaks from using the keyboard

Special, ergonomically-designed keyboards where the keys are split and contoured for the hands, can be purchased.

Eye Strain - Eye strain is quite common among people using monitors over extended periods of time. It can result in irritated eyes and blurred vision.

Solutions - to reduce eye strain, users should look away from the monitor and focus on a distant object from time to time to relax their eye muscles. A screen glare deflector can help some users.

All new monitors must comply with EU standards which ensure that radiation emission is as low as possible and all new screens must be fitted with tilt and swivel stands.

Room lighting can have a major effect on eye strain.

Windows should be fitted with non-reflective blinds, preferably beige in colour.

Computers should be positioned so that sunlight from the window does not reflect on the screen.

The optimum position is at right angles to the source of natural light.

Worktops should have a matt surface in order to reduce glare.

Back problems - Sitting at the computer for long periods of time is never comfortable. Leaning back in the chair reduces the pressure on the spine but then the arms have to reach forward to the keyboard creating muscle tension which leads to aches and pains in the neck, shoulders, back and arms.

Solutions - while working at the keyboard, the correct seating position is sitting upright with the feet flat and the lower arms and thighs in a roughly horizontal position. Adjustable chairs that give the maximum support for the back are also best. (NOT a Comfortable chair!)

Sufficient room is needed for the monitor to be moved back and forward. Ideally, the top of the monitor should be at eye level.

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Worktops should have a fixed height between 660-730mm is required (720mm is recommended). A worktop depth of 760-840 mm is required to give the user sufficient distance from the screen while working.

Even with a comfortable working environment, it is still good to stand up, stretch and move. 

Power supply:

Computers are generally connected to 240v mains electricity and must be treated with care. The computer should be properly earthed and the plugs should have the correct fuses

Trailing electrical leads should be avoided to reduce the risk of tripping or them being damaged.

Leads should preferably be in trunking or be safely tied out of the way

There should be enough power sockets to avoid power sockets being overloaded

Mains plugs and leads must be checked for safety once a year

If the computer is moved or opened, the power cable must disconnected

Fire risks:

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In case of a fire, the fire extinguishers should be powder-based or CO2 (carbon dioxide) devices. Water-based fire extinguishers should not be used on electrical appliances.

Food and Drink:

It is best to avoid eating and drinking near to computer equipment. Food crumbs can prevent a computer mouse or keyboard from working properly. Any spilt liquids are a possible fire risk near electrical equipment and can easily ruin items such as floppy disks.

TASK Design a poster to advertise one of the possible health risks from using the computer. Advise the reader what they should do to

prevent or minimise this risk. Attach your poster to this page.

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Word Processing v Desk Top Publishing

Common features of a Word Processor and Desk Top Publisher.

When typing a document on a word processor it is possible to edit (or change) and format (or alter the layout) of the text.

Feature Example

Editing – Deleting or adding characters or punctuation

The cats sat on te mat (original)The cat sat on te mat (deleted character)The cat sat on the mat (added character)

Editing – replacing characters The cat sat on the mat (original)The cat sat in the mat (replaced character)

Editing – rearranging sentences The cat sat on the mat (original)On the mat, the cat sat (rearranged)

Editing – copying blocks of text so that it may be used or repeated elsewhere in the document

The cat sat on the mat (original)The cat sat on the mat (copied)

Editing – spellchecking or grammer checking. Scanning the document or selected text for basic spelling or grammatical errors. A green squiggly line under a word or sentence shows a grammatical error and a read squiggly line shows a spelling error.

the cat sat on tho mat

Can be limited to words that are stored in the dictionary and grammar checks can show errors when in fact there are none. This is due to the fact that English grammar is very difficult.

Formatting – Embolden characters to make words or characters stand out

The cat sat on the mat (original)The cat sat on the mat (emboldened)

Formatting – Italics The cat sat on the mat (original)The cat sat on the mat (italic)

Formatting – UnderlineThe cat sat on the mat (original)The cat sat on the mat (underlined)

Formatting – Changing the font size and the font

The cat sat on the mat (comic sans size 10)The cat sat on the mat (lucida handwriting size 10)

The cat sat on the mat (size 14)

Formatting – Changing the spaces between the characters and/or the lines

The cat sat on the mat (original)

T h e c a t s a t o n t h e m a t

( e x p a n d e d s p a c i n g o f

c h a r a c t e r s a n d d o u b l e

l i n e s p a c i n g )

Formatting – Changing the justification of the text

Left justified means that it will line up on the left hand side and be ragged on the right.

Centre Justified

Right Justified means that it will line up on the right and be ragged on the left.

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Fully justified means that the words will be spaced out so that it is straight on both the left and right hand side of the text.

Formatting – extra features

Changing the size of the margins Bullet points or1. Numbering

Page breaks – forcing the work to start on a new page

Borders – putting boxes around text

Other features found on Word Processors

Help facility Creating and editing tables (as above) Drawing tool so that you can draw your own basic shapes that can be grouped

together. Inserting pictures/clipart Mail Merge – where a standard document can be merged with information from

a data source (eg database) and inserted into the document. Companies use this to send out personalised letters to their customers – they write one letter and merge it with their customer database.

Word Count

Differences between a Word Processor and Desk Top Publisher

Word Processor Desk Top PublisherYou can start typing straight away on the page

You need to create a text box before you can start to type

Word wrap – words are never split up to start a new line

Does not have word wrap – will usually split the word or insert a hyphen when starting a new line

Spell checker works through the whole of the document

Spell checker only works in the selected text box

Thesaurus and Grammar checks Not availableCan use Autocorrect to automatically correct basic spelling mistakes

Not available

Not available Ability to layer objects – place one on top of each other or make one layer transparent

Not available Ability to flip or rotate objects so that pictures or text frames can be put onto its side or diagonally

Remember that software is being developed all the time and although these differences are generally true, this may not be the case in the future.

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TASK Complete the past exam paper question

(May 2003 question 4 higher paper)

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Graphics ProductionAs the development of software continues these features of graphics production can now be found in Word Processors as well as Desk Top Publishers. Graphics production allow you to create and change images (pictures)

Common Features of Basic Graphics Packages

Fill - adding colour to a shape

Shadowing – where a shadow is added to the drawn object

Three Dimensional Shapes – making shapes look real by adding depth to appear they have a 3-D look.

Layering – put one object on top of another. Here the two circles have been placed on top of the triangle. They have also been grouped together so that they can be moved as one image.

=

Resizing – Changing the size of the image by either stretching the image or changing the magnification.

Orientation – Rotation – turning the image around an axle. Basic packages rotate around the centre of the image but more powerful packages allow you to choose the axle point.

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Orientation – Flip – creating a mirror image of the original either horizontally or vertically.

Crop – removing unwanted areas from the image

Task Complete the past exam paper questions

Question AnswerA designer is using a graphics package to create a diagram. The “resize” feature can be used to change the size of the image.

Describe what these four other features do.

Flip

Crop

Fill

LayerWhat software tools have been used to change picture A into picture B[2] 1.

2.

A student in a school workshop uses a Computer Aided Design (CAD) package to create a design on the screen. Describe three tools that would be used when creating the design on the screen[3]

1.

2.

3.

(Question 4 2005 Foundation Paper)

Horizontal Vertical

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Notice the cursor changes to a small cross when you place it over the black square in the bottom right-hand corner of the active cell

By holding the left mouse button down and dragging the selection over the cells you choose you can see how it will replicate the list – guessing the next entries.

When you release the left mouse button it fills the cells with the replicated information – this will also work for copying formula

SpreadsheetsSpreadsheet software is used for data modelling applications such as financial budget sheets because they are very good at supporting the trying out of many different types of data as ‘what-if’ scenarios.

Features of spreadsheet software

Sheets and Workbooks – a file is known as a work book and within it are many sheets that can be used (just like your maths exercise book)

Columns and Rows – The spreadsheet grid are made up of lots of cells, the vertical line of cells are called columns and the horizontal line of cells are called rows.

Format Cells – Cells can be formatted so that they display information in a particular way. The most popular format is Currency that insures that all information shows the currency symbol chosen.

Formula – very powerful spreadsheet facility because they automatically recalculate a new result each time the data is changed in the spreadsheet.

Functions – are named, ready-made calculations that we can use as part of our formulas.

Replication - is when you copy the contents of a cell (which contains a formula) to other cells down a row or column. (you can either use copy and paste or drag the small square in the bottom of the active cell)

Cell reference (name)

Rows

ColumnsActive Cell

(highlighted cell)

Number format

Currency format

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Task This is a spreadsheet of the money that Kathryn has spent in one week.

Question Answer

Identify the cell that gives the total bus fares[1]

Give two ways that the amounts shown in columns C and D could be made easier to understand.[2]

1.

2.

Describe how this could be done.[2]

Write a suitable formula to be put into cell D15 to calculate the total amount spent.[2]

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A paint shop owner uses a spreadsheet to keep a record of paint sold over one year.

Question Answer

Cell C3 contains a formula to work out the cost of paint per month. Describe a quick way of putting a similar formula into cells C4 to C14[2]

Describe how a chart or graph could be produced to show the number of tins sold each month.[3]

The table shows part of a spreadsheet file

Question AnswerGive the cell reference that contains the cost of the stapler

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[1]Give the cell reference of one cell containing numeric data[1]Identify a column that contains data that is left justified[1]Identify one column that should be formatted as currency[1]Give one advantage of entering just ‘Y’ or ‘N’ in the ‘In Stock(Y/N)’ column rather that the full words ‘Yes’ or ‘No’[1]

A spreadsheet is used to process data about average rainfall over two years.

Question AnswerState one better heading that should be included in cells B2 or C2 to make the data in the spreadsheet more understandable[1]State one reason why it would not be sensible to calculate the total of column D[1]

The table shows a spreadsheet

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Question AnswerIdentify the row which contains information about monitors[1]Give the cell that contains £40.00[1]Give the title of one of the columns[1]Give a cell that is left justified[1]The £ symbol is not typed in but appears on the spreadsheet. Give one reason why it appears[1]

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Data Logging & Control SoftwareDefinition:Data logging can be defined as the capture and storage of data for use at a later time.If you want some form of output, based on the data that is collected then data logging can be used with control software. For example, you could monitor the temperature of a greenhouse and if the temperature got to high a motor could be used to automatically open a window.

How the data is collected:Sensors are used to input the data into the data logging equipment. Almost any physical property can be measured with the correct sensor.

There are two categories of sensors:

Digital sensors - these are either on or off i.e. a light gate sensing something breaking a light beam. Such sensors can often be connected directly to a computer as the data output is already digital.

Analogue sensors - these measure some physical quantity by converting it into a voltage. The voltage signal is then converted into digital form by an interface and either stored or transferred directly to a computer.  The vast majority of sensors are of this type.

Examples of sensors that can be used when data logging:

heat light sound

altitude magnetic forces pressure

movement wind speed oxygen levels

humidity  pH radiation

One advantage of data logging is that it can be done in places that are hostile for humans such as inside a nuclear reactor or a volcano. Data logging equipment therefore often has to be very robust so that it can resist extremes of temperature or radiation for example.

Another advantage of data logging is that regular data can be collected over very short or very long time periods that would be impossible or impractical for a human operator.

Example: data logging equipment can record hundreds of readings in less than a second. (Imagine asking a human to take 100 pressure readings inside a room as an explosion is set off) 

Example: data logging equipment can take readings at regular intervals, 24 hours a day, for months or even years on end. (Imagine asking a human to measure the temperature of the cooling water flowing into a river from a power station very half hour, 24-hours a day for 6 months!)

Many sensors produce analogue signals which must be converted to digital signals so they can work with computers. An analogue to digital converter changes the varying voltage from the sensor into pulses which are the digital equivalent of the voltage value.

How the data is stored:

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The data is usually stored in memory or some form of backing storage as it is collected.Some data logging equipment is designed to be linked to a computer (although this can be a wireless link). This would be suitable if an experiment is taking place in the laboratory for example.

If you wanted to record data out in the field then data logging equipment would be needed that could measure and store the data until the unit is collected.

The equipment would then be connected to a computer so the data can be down-loaded. This could still be done out in the field if a laptop computer was used to collect the data.

How the data can be displayed:Once downloaded to a computer, software can be used to display the data. This can be in the form of graphs or tables on a monitor or on a print out.

The data can also be loaded into a spreadsheet program for analysis.

Examples of data logging in use:

1 - In a hospital:

The sort of life support systems found in intensive care units will make extensive use of data logging equipment. The patients will have sensors attached to them which will continuously measure data such as temperature, blood oxygen level and heart rate.

Advantages: 24 hour monitoring takes place without having to use

a human operator who would need breaks, could lose concentration or could get tired and make mistakes.

Alarms would be set off automatically if any measurements exceed a safe value.

A continual record can be stored or printed out of everything that is being measured.

2 - Recording over an extended period of time:

In an experiment during the last UK eclipse, light sensors and temperature sensors were used to continuously recorded the light intensity, the temperature in the sunlight and the temperature in the shade.

The data logging took place at regular intervals over four hours. Software was then used to produce a graph from the data that was collected.

Advantages: Many accurate reading can be taken at regular intervals over an extended

period of time without risk of 'human-error'. The data is digital so it can be transferred straight to software which can

display it or analyse it further.

Summary:

Advantages of using data logging in experiments:

Increased accuracy is possible compare to

Sensors can be sealed inside the equipment and this avoids the risk of someone taking a

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measurements taken by humans

measurement and interfering with the experiment.

Many measurements over VERY short time periods are possible

Example: Sensors can record hundreds of measurements during experiments lasting less than a second.

Regular measurements over VERY long time periods are possible

Example: Sensors could be set up to record the movement of a volcano over months or even years.

Data can be collected from hostile environments Sensors can be designed to operate in outer

space, radioactive areas, the ocean depths, high in the atmosphere or at the poles.

Control:

Control technology is used to allow a computer to respond to data that has been captured or recorded using sensors.

An example would be a control system to maintain the correct conditions in a greenhouse automatically.

Sensors could measure the temperature and amount of light.

A control program would make decisions if the readings got outside a certain range.

Motors could open windows if the temperature got too high or switch on heaters if it got too low.

Motors could close blinds if the light was too much or relays could switch on lights if it was too dark.

The control program is a series on instructions written in a particular programming language. This language has commands to read input sensors, process the data in some way and make decisions and then control outputs such as motors, lights, relays etc.

Many control languages have the following additional features:They can use and alter variables. This is a way of giving a number a label (such as A=12). The value of the variable can be easily altered (i.e. A = A + 1 would add 1 to whatever A was before) or used in a program in decisions (i.e. IF A >= 10 MOTOR OFF).

The can use LOOPS to make part of a program repeat until a certain condition is met (i.e.  REPEAT         T = TEMPERATURE READING (from a sensor)         UNTIL T = 90) The can use procedures (or macros). These a self-contained bits of program that are used for commonly repeated tasks in the main program. This avoids having the same bits of instruction coded repeated in lots of different places in one program.  A procedure is usually given a simple name by the programmer and then the main program uses this name to run it.

Types of Control Languages:

Command Line languages:

These use a wide range of different commands and they are usually typed into the computer line by line. When the program runs it starts at the first line and then either

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moves through the program one line at a time or is directed from one set of instructions to another depending on the way the program is written. The way the commands are entered has to be exactly right (this is called the SYNTAX) and it can take a long time to learn. Unfortunately, many different control languages will use a different syntax to do exactly the same job.  For example:

Program 1 Program 2

REPEAT 10T=TEMPERATUREIF T>10 THEN ENDEND REPEAT

LOOPT=TEMPERATUREUNTIL T>10END

Logo:

This is simple command line computer language that is usually used to draw shapes on a computer screen but it can also be used to move a motorised buggy or "turtle" around the floor.

Example Logo instructions: REPEAT 4 [FORWARD 20 RIGHT 90 ] These instructions would make the 'turtle' draw a square. It would repeat 4 times the commands to move forward 20 and then turn right 90 degrees.

Flowsheets: An example of this is Flowol. To construct a program, commands are dragged and dropped onto a screen and connected by lines. When the program starts it moves from one command to the next along the connecting lines. The individual commands can be edited and include Input commands, output commands and decision commands etc.

Flowsheet programs are usually easier to follow than command line programs.

TASK Ask your teacher for the WinLogo exercise booklet as well as the Flowol exercise booklet

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Presentation Software

Presentation software allows the user to present information by interacting with the presentation or can allow it to run automatically.

The software usually has the same basic features as found in a word processor or desk top publisher to allow the user to input information. However, the software has some more interesting features that allow the presentation to be more entertaining to the audience.

The presentation can include the standard text and images (just like the DTP) but you can also include animation, video and sound

Basic features of Presentation Software

Narration can be added by recording the spoken work Facility to check the presentation & rehearse timings Animated clipart Control pathways through screen of information through navigational aids such

as “buttons” Entrance and Exit of images and text Inclusion of video clips

TASKComplete the past exam paper questions

Question AnswerA sales person is using presentation software to produce a slideshow. State three features of presentation software, other than text, that can be used to make the presentation more interesting.[3]

1.

2.

3.

A journalist types reports and presents them as multimedia presentations. Give two features of a desktop computer that would make it more suitable than a palmtop computer for these tasks.[2]

1.

2.

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Page 70: Year 10 ICT Booklet

WebpagesComplete the past exam paper questions

This screen shot shows a typical Internet Web Browser displaying the home page of a web site.

Question Answer

What is meant by a homepage? [1]

The homepage contains information that frequently changes. State one way that the user can make sure that the home page shown by the browse is up-to-date?[1]

Give two ways the user could move to a different web page.[2]

1.

2.

Give two features, other than text and graphics, that might be included on a web page.[2]

1.

2.

Question 4 2005 higher

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