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An embedded computer is a single chip that contains all of the elements that are essential for any computer

Embedded

All of the following contain an embedded computer: x x x x

telephones televisions cameras washing machines

Palmtop Personal Digital Assistant (PDA)

Laptop

A PDA was originally developed as an electronic organizer. PDA’s are now available with cut down versions of the main Office software, e.g. Microsoft Word. Palmtops have a built in keyboard, PDA’s do not.

A portable Personal Computer.

A Personal Computer (PC). The desktop PC Microcomputer has a central processing unit housed in a metal or plastic case (often called a tower unit). A keyboard and mouse are usually used to input data and a monitor to output the data.

Mainframes are large, powerful computers that can carry out many different tasks for many different people at the same time. They are used by large companies such as:

Mainframe

x x x

Banks - for managing thousands of customers accounts each day Airlines - for dealing with bookings, tickets, cancellations etc Police - for storing and processing all of the data collected each day about crimes.


Basic Computer Process

Advantages of a computer • • •

Disadvantages of a computer • • •

Faster processing Saves on storage space Password protection to files

Initial cost of purchasing computers Over reliance if a power cut Staff retraining

Data

Raw facts and figures e.g. 21041926. Can be taken from readings from a sensor or survey.

Information

Processed data with a meaning e.g. 21/04/1926 is the Birth date of Queen Elizabeth II

Knowledge

Derived from information which has rules applied to it e.g. 21/04/1926 is the Birth date of Queen Elizabeth II, so I will have to send her a card this month.

GIGO = garbage in garbage out (if incorrect data is entered into the computer, incorrect data will come out) Data can be coded and validated

Houses coded as

TR = terraced DT = detached SD = semi detached

Gender

M = Male F = Female


Advantages of coding data; x x x

it takes up less memory on disc it is faster to type in it is easier to do searches on standardised data.

Advantages of using a computer to process data x x

x x x

Improved speed of access to data Faster processing/search/sorts A variety of output formats available e.g. printed reports, mail merged documents. Etc. Easy to transfer data Improved variety of services Increased security Saves on storage/office space

Disadvantage x x

Initial cost of purchasing the computer Over reliance e.g. if there is a power cut you cannot use it.

Errors that can occur Transcription /typing errors

typing in the wrong character by accident egg 2 instead of a 7

Transposition Errors

i.e. keying in, in wrong order

Data entered in wrong format

e.g. date is 2002/ 09.11 instead of 11/09/02

egg 56789 instead of 57689

We use validation techniques to cut down errors Validating data ‘Validation is the process of ensuring data is valid and legal’

When creating fields in a file the user often puts controls over the way in which data is entered. This ensures that; * data is entered into the correct format * data is sensible * reduces the risk of mistakes on data entry

Validation type Range checks

Explanation Data is between stated ranges

Format checks Presence checks

Dates There must be a character present in a particular place e.g. the first 2 letters must be SC No added to a code

Check digits

Example Membership No must be between 1 and 1000 12/04/03 SC6785

Bar codes


™ A database is an organised collection of related files of data ™ A file is an organised collection of related records ™ A record is a collection of related fields

Also known as a PRIMARY KEY

™ A field is a collection of related data

Advantages of a spreadsheet • • • • •

NOT does calculations for you!!!

Accuracy of calculations ‘What if’ investigations Draw graphs and other output forms Save the formulas and data Automatic recalculation if data changes

Simulation model -

A program that models a real world situation

Examples: •

Traffic flows

Supermarket flows

Flight simulation

Virtual reality Advantages

Disadvantages

Computer have to calculate many large

Not 100% accurate

formulas quickly

Requires powerful computers and

Display as graphics

Dangerous and expensive to do test in real life

complex programming


Basically, all computer control means is using a computer to control the action or movement of an object / system. For example, a burgalar alarm. A computer uses the following control port to monitor and control a house hold security system

0 means when something is OFF 1 means when something is ON

alarm light

motor to close shutters

siren

sensor on front door

pressure mat

0 0

1 0

2 0

3 0

4 0

Everything is OFF

This is what would happen to the display of bits in the following situations:

a) A burglar has stepped onto the pressure mat 0 1

1 0

2 0

3 0

4 1

b) A burglar has opened the front door 0 0

1 0

2 1

3 1

The alarm and pressure mat would be triggered.

4 0

The siren and sensor on front door would be triggered.

c) If the burglar stands on the pressure mat and opens the front door, the alarm light would come on and the siren would come on and the window shutters would close. 0 1 

1 1

2 1

3 1

4 1

Advantages of data logging • • • •

24 hours/365 day monitoring Human do not have to be there Accurate readings Accurate recordings


Theatre and, concert tickets, holidays, flights etc, can be booked using the Internet. Agencies and the home user can now access remote online databases for their computer enquiry and booking system. People can search for holidays etc. to suit their requirements and make provisional or firm bookings.

Advantages to the online booker x

Services are available 24 hours a day

x

Alternatives can be proposed if first choice not available

x

Access to data on a wide range of holidays including special offers.

x

Bookings are instantaneous so little possibility of overbooking because once a seat or holiday is provisionally booked this will appear on the database.

‘Computers linked together’ By joining computers together to form a network, they are able to share one printer. This means that more money can be spent buying a better quality printer and that the printer is being used much more of the time. As well as sharing hardware, a network allows computers or users to share software and data. Data can be transmitted very quickly between networked computers. A computer connected to a network is known as a 'work-station' or ‘terminal’.

PLOTTER

Terminal

Terminal

Fileserver

PRINTER CD ROM SERVER

HARD DRIVE


There are different ‘sizes’ of network depending on how far the computers are that you want to link together.

Local Area Network (LAN). - used when computers are close together, in a single office or two buildings that are separated by a road. A file server is often used to store each person's data files. This means that people can log onto any machine on the network and access their files. They are not restricted to just one machine. Another advantage of having all of the files stored in one place is that a back up copy of every user’s files can be made easily. To log onto a LAN, you usually need a user name and password. The user name identifies you to the file server so that it can 'serve' you the correct files. The password ensures that the user name really does belong to you. The school uses a LAN. Think about how you use the computers in school. You can access your files and print anywhere!

Wide Area Network (WAN) – used to connect computers across the country / world. Many modern companies have offices, shops or factories in various locations around the country, and for large corporations, across the world. Even though staff work in different places, they often need to be able to access the same information no matter where they are. Computers on LANs in one building can be connected to computers on LANs in another building usually through the telephone system, often using a modem. They can also be connected via fibre optic cables, microwave links or satellite. By linking LANs together, the network is no longer local to one building; it is now spread over a wide area. It is known as a Wide Area Network (WAN) Did you know that the largest WAN in existence is the Internet?

Advantages of a network ™ Share printers and other peripherals ™ Email ™ Share programs ™ Share data files

Disadvantages of a network ™ Open to hacking ™ Spreading of viruses ™ If file server crashes no one can use the network. ™ Needs extra staff to maintain the network.


Bus This is one method of connecting computers together and is the simplest one to connect together. A single cable joins all of the workstations, printer, file server and other components together. At each end of the bus is a 'terminator'. This is a piece of hardware which prevents signals bouncing back and forth (echoes).

Advantages x x x x

Disadvantages

Easy to install Easy to add extra workstations Uses less cable than a Star network Best choice for temporary networks

x x x x x

If there is a problem with the central cable, the entire network stops working If there are a lot of workstations on the network, data can travel slowly. Data collisions can happen as the network becomes busy Low security - every workstation can see all of the data in the network Limited cable length and a maximum number of workstations

Ring In a ring network layout, all of the computers are connected to one another in a circle. The data passes from one computer to the next one and then all the way around the ring layout until it reaches the destination computer. Advantages x x x

Transmission of data is fairly simple as it only travels in one direction No data collisions Extra computers can be added easily with little effect on performance although you have to shut down the network to be able to do this.

Disadvantages x x x

x

If a single machine is switched off, the network doesn't work If a cable breaks, the network doesn't work Data must pass through every computer until it reaches its destination. This can make it slower than other network layouts. If there are any problems with the network, they can be difficult to identify the cause.


Star In a star network layout, each workstation is connected by its own cable directly to the server. Star networks are usually the layout of choice in schools and offices because they tend to be the most reliable of the topologies. Advantages x

x

x

Star networks are very reliable. If one connection fails, it does not affect other users Very few data collisions as each workstation has its own cable to the server Good security - no workstation can interact with another without going through the server first

Disadvantages x

x x x

The most expensive network layout to install because of the amount of cables needed Installing the network usually needs experts to set it up Extra hardware such as hubs and switches may be needed If the server crashes or stops working then nobody will be able to access their files or use the network.

*PAPER 2 SPECIAL TOPIC*

A knowledge-based system which attempts to replace a human 'expert' in a particular field. It diagnoses problems and gives advice on that the cause of those problems are. They can also give advice on solutions.

The system will consist of; 1. Knowledge database – large database 2. Inference Engine - a set of rules for making deductions from the data (inference engine) 3. User Interface with facilities for searching the knowledge database

There are special high level languages used to program expert systems e.g. PROLOG


Example of an Expert System A medical diagnosis expert system (e.g. MYCIN) would have information about diseases and their symptoms, the drugs used in treatments etc. A patient is asked by a doctor about symptoms and the replies are input to the expert system. The computer searches its database, uses its rules and makes suggestions about the disease and its treatments. Sometimes probabilities are assigned to diagnoses. The computer does not take the place of the doctor but can be used to help the doctor make decisions.

Medical screening for cancer and brain tumors

Matching people to jobs

Other Examples of Expert Systems

Training on oil rigs

Advantages

Diagnosing faults in car engines

Legal advisory systems

Disadvantages

1. The computer can store far more information than a human.

1. Over reliance upon computers

2. It can draw on a wide variety of sources such as knowledge from books, case studies

2. Some ‘experts’ could lose their jobs or not be given training if computers are available to do the job.

3. The computer does not 'forget' or make mistakes. 4. Data can be kept up-to-date. 5. The expert system is always available 24 hours a day and will never 'retire'. 6. The system can be used at a distance over a network. So rural areas or even poorer third world countries have access to experts. 7. Provides accurate predictions with probabilities of all possible problems with more accurate advice. 8. Some people prefer the privacy of talking to a computer.

3. Lacks the 'human touch'! – lack of personal contact 4. Dependent upon the correct information being given if data or rules wrong


*PAPER 2 SPECIAL TOPIC* Robots are used in factories to produce goods. A robot can be defined as a device that has been programmed to carry out repetitive mechanical tasks. There are many different types and shapes available, but each has the same basic features; ™ Sensors that collect input information ™ Microprocessor to process the information ™ Actuators, which produce movement



Carry out undersea maintenance for oil rigs Pack goods, e.g. put bottles in boxes

Space exploration vehicles

Produce cars, fix windscreens, spray paint, welding

Robots can be used to:

Move goods, such as car parts, rolls of newsprint, around factories

Intelligent wheelchairs for disabled people Security devices in homes and factories and offices Testing equipment such as the lifespan of computer keyboards 

There are many other applications for robots Advantages of using robots: 1. Robots can carry out monotonous, repetitive tasks, lift heavy weights 2. Reduce wage costs as robots replace workers; it is estimated that one robot replaces six workers 3. The quality of the work does not vary 4. A robot can work for 24 hours a day, they do not need rests and never go on strike 5. Robots can work in places that are dangerous to humans, e.g. in darkness, in low and high temperatures, in radioactive environments, deep under the sea 6. A robot can work much faster than a person

Disadvantages of using robots: 1. People lose their work 2. Robotic systems are expensive to buy and to set up



An embedded system has a board with a ROM chip which has a stored specialpurpose application program which controls a machine. This program is run continuously as long as the system is switched on.

Input data may be received from sensors; the program processes the data and may send output signals to control the machine.

Washing machines, microwaves, traffic lights, are all examples of embedded systems. They all have programs stored on ROM controlling their actions.


*PAPER 2 SPECIAL TOPIC* Item stock level is how many of the item are available in a shop. There are several reasons why shops need to keep count of how much stock they have: ™ ™ ™ ™

To ensure that there aren't too many items in stock - they can turn bad or be out of date; Not enough space to store reserves; Ensure that too much money has not been tied into stock Ensure that enough stock is available

Shops know how many of a particular item they usually sell and it must be ensured that enough are available. A good stock control system can keep track of how many of each item are in stock, when and how many to order and the best or least selling items. A sales terminal, where the barcode of each item is scanned, can keep count of how many of each item is sold and as they are sold the stock level is immediately changed. The system can also see when items need to be reordered and count how many need to be ordered. Sophisticated systems can automatically prepare an invoice to the shop headquarters on electronic form using EDI (Electronic Data Interchange). Companies can accept an order over the phone or by post - someone would have to enter the data into a computer; or they could receive an e-mail via the internet. The information on the order is verified and validated before it is processed. When goods are delivered, the customer is sent an invoice. As the invoice is processed the stock levels are updated.

Inputs ™ Barcode reader scans at the sales terminal. ™ PDET - Portable Data Entry Terminal to count how many of each item are left on the shelves by making an occasional stock check. A stock system is a combination of real time process and batch-processing. A sales terminal system keeps count of the stock available in real time - the situation can be checked at any time to see what is in stock. The system prepares an order of what needs to be ordered using batch-processing, which is sent at particular occasions.

Outputs ™ ™ ™ ™

Lists of how many of each item are in stock. A list of the items to be ordered. Electronic order to be sent using Electronic Data Interchange. Sales patterns.

Advantages 1. 2. 3. 4.

Keeps the latest count of the items in stock. Warns when to reorder. Prepares and sends orders automatically. Purchase and sell goods on-line.

Disadvantages 1. Barcode needed on each item. 2. Installation cost.


Diagrams to show how automatic stock control works:

It contains details of all transactions that have occurred in the last period of processing.

Kept up to date by applying the transaction file.

*PAPER 2 SPECIAL TOPIC*

It is now possible to make book a holiday, a seat on a train or bus, a flight, a room in a hotel, or a theatrical performance on-line! Travel agents have computers in every branch or shop which are all connected with one central administrator where all bookings are recorded (multi-access system). A flight can be easily booked on the internet therefore avoiding the need for the customer to fill in forms. Theatres use computer systems to record seat bookings where the customer phones in their request for the theatre to then enter the booking into their system.


Input

• The customer must enter details to make a booking, e.g. name, address, date, numbers etc. This data can be entered on a terminal computer (multi-access system), into an electronic form on a web page, on a paper form, or by typing directly while the customer is on the phone.

• The data is validated during the process to ensure that it is correct and makes sense. The computer will find whether there is a vacancy for the booking, and if so will record the details of the booking in the database.

Processing

• A booking must be recorded and processed immediately so that the same place or seat cannot be taken by anyone else. • This is called real time transaction processing. Credit or debit cards are used to pay for on-line or phone bookings.

Output

• Receipts are printed and given to the customer as proof to confirm the booking and to record details. This may be in the form of a receipt, or e-mail if the booking was made on the internet. A voucher with the customer's details is printed.





Security Obligations Secure pages are used to transfer information over the internet, so that personal data cannot be seen or stolen by anyone else.  

Advantages of booking systems 1. Using a computer reduces the enormous workload of processing paper documents

Disadvantages of booking systems

2. Bookings can be made or recorded via the internet

1. A number of people were unsure to start with about transferring their personal information over the internet due to the possibility of it being intercepted by someone. This is now virtually impossible due to the encryption of secure pages

3. A computer system can process a pile of data rapidly

2. No proof of a site's authenticity e.g. bogus merchants

4. The data is validated at the time

x

5. Immediate notification if the booking has been made

x x x

Businesses record bookings on the computer system Customers can order by phoning the business or booking on-line Information regarding the items booked and the customer's information is validated Secure pages are used to transfer booking information over the internet


POS = Point Of Sale    

The POS is essential to the operation of the supermarket. It is here that the customers pay for the goods. It is here that the shop sales information is recorded. It is here that the information on what each customer buys regularly is collected.


Supermarket Stock Control The task of recording and maintaining stock levels is called stock control. A stock control system must keep an up-to-date record of all the stock held and place orders for fresh deliveries if stock runs low. Importance of Stock Control - Adequate stocks must be maintained to supply a customer with goods with minimum delay. If customers find goods are regularly out of stock they will go elsewhere. - To keep business expenses to a minimum, goods must not be overstocked. By keeping stocks to a minimum, a business can limit the amount of money invested in stock and also reduce the risk of stock deteriorating before it can be sold. Minimum stock levels also reduce storage costs such as warehousing, heating, lighting and security. The Process 1. When an item is scanned at the point of sale terminal (POS) the bar code number is passed to the computer which then searches for the details of the item in the database. 2. Once the data has been found it is passed back to the POS where it appears on the customers receipt. Some of the fields in the database are for reference and would hold data describing the item and its price. 3. Other fields such as how many there are left in stock would be updated constantly as the items are sold.

The master file holds all of the information about each product in the supermarket. The above example shows what would happen to the master file is 20 Heinz Baked Beans were sold in one day.


Sales Transaction File

This diagram shows how the stock system works and when the master files are updated.

Sort into stock order file

Sorted Sales Transaction

Master File Update Master

Management statistics

Re order List

Updated Master File

The master files must be backed up so that no data on the products is lost if there is a system failure of some sort.


€ € € € €

Information on goods is held on the bar-code. Stock control depends on what comes from the bar-code reader. Scanner is located at the POS. Reads information fast and accurately. Hand scanners used by shop staff – now also for customers (self service).

Scanning and typing in codes are the most common ways of entering data at the POS. Other methods of entering data in shops: OMR (Optical Mark Reader) sheets for ordering stock Portable Data Entry

(PDET)

Portable Data-Entry Terminal: a calculator-sized device with a built in bar code reader attached The PDET can be connected to a computer and data downloaded at the POS. It also makes it easier for shop assistants to perform a manual stock-check, which takes place from time to time so that the computer's view of stock levels is compared with real-life (if they differ, it is probably down to shop-lifting); speeding up data-entry and reducing mistakes means that fewer staff are needed, with less disruption to customers. e.g., Sainsbury’s Kimball tags e.g. Clothes shops Pre-punched tags affixed to goods, containing the size and style data that speed up inventory control. Small, rectangular cardboard tags which are removed from garments at the POS and placed temporarily on a spike near the till; at the end of the day all the Kimball Tags are collected, and placed in a card-reader to input the data (e.g. Product-Code) into a computer to update the stock database for purposes of stock-control. Touch sensitive menus or screens – these are used at the self – service checkout or in fast food restaurants.


Online Shopping € € € €

Shopping for food is an important part of e-commerce. You can shop quickly without moving from your home. Goods are collected from the shelves and sent to the customer. The customer pays with a plastic card (EFT – Electronic Funds Transfer).

1. As the customer selects the goods they are placed in a 'virtual trolley' and goods that are bought regularly are highlighted on the list which makes shopping easier. 2. The goods are delivered from the shop to the customer. 3. When shopping on-line payment can be made through Electronic Funds Transfer (EFT) which is again very convenient for the customer. A secure payment service is used to ensure there is no misuse of credit cards over the Internet. Online Shopping SUPERMARKETS For the customer The advantages for the customer shopping for food on-line are: € Customers can shop every day of the year and at any hour of the day or night. € Goods will be sent directly to the customer. € Very convenient system for elderly people or anyone who has difficulty moving or lifting heavy goods. € No waiting by the POS when the shop is busy. The disadvantage to the customer is that you cannot see the goods so as to make sure they are of the best quality, or fresh.

For the supermarket The disadvantage to the supermarket is that they have to invest in refrigerated vans, which can carry the goods in top condition to the customer.

Online Shopping GENERAL RETAIL

For company Reach wider market For customer • • •

24 hour / 365 day shopping Don’t have to leave home (disabled) Savings on travel and time costs

There is a danger of debit / credit card numbers being intercepted by hackers during transmission and used to make unauthorised purchases. Criminals can set up fake web sites offering goods or services often using the name of a genuine company. This can lead to people spending money on goods they will never receive as well as damaging the reputation of a genuine business.


Involves the following: x x x x x x x

Cheque processing EFTPOS – Electronic Funds Transfer Point Of Sale ATMs Credit cards Debit cards Smart cards Home banking/ telebanking

Cheque Processing A cheque is a paper form that is issued by a bank that an account holder can use to authorise payment to another person or organisation. An account holder must write these details on the cheque for the payment to be authorised: x

the name of the person or organisation that it is payable to

x

the date

x

the amount that it is for in figures and in writing

x

a signature


  What a cheque  looks like          Branch  

Bank of Monee Date…… Pay…………………… Amount……………….. ………………………… A N Other 46-45-90

number

37465327

102201

Account number

Cheque number

The numbers at the bottom of the cheque are written in special magnetic ink. These are: 1. The amount the cheque is for is keyed in manually by a data input operator and printed on each individual cheque in magnetic ink. 2. The amount in words acts as a check if the figures are hard to read. The magnetic ink enables the cheques to be read very quickly, in batches, by a special reader. This process is called MICR or Magnetic Ink Character Recognition. A cheque guarantee card usually accompanies cheque payment. The card number is written by a retailer on the back of a cheque and guarantees that the bank will honour cheques up to a certain limit irrespective of the account holder's balance. When the cheque is paid in at a bank it undergoes a chain of processing events and only then is money transferred from one bank account to another. The method of processing the cheque is called cheque clearing. This normally takes several days.


Advantages of the DEBIT CARD  

People do not have to carry cash – use card to pay. Money is transferred straight to the shop’s bank account using EFT.

Disadvantages of the DEBIT CARD  

Not all shops have a POS terminal so can’t always pay by card. The information on the magnetic strip can be damaged by the use of strong magnets.


The money on a cash card can be spent at any retailers with the equipment to read the card. Money can also be transferred directly from one card to another using a special electronic wallet that resembles a pocket calculator.

Smart cards are plastic card that contains a microprocessor with a memory.

Smart cards programmable cards

The memory can store much more information than a magnetic stripe on the back of a credit or debit card.

Unlike a credit or debit card that creates a computer record of who the transaction was made by, a cash card does not and is therefore anonymous.

Access to the cash on plastic smart cards can be protected by locking it with a 4 digit PIN. Retailers like smart cash cards because they offer the following advantages: * * *

Accuracy - mistakes can't be made with change Efficiency - don't have to waste time counting and handing out change Security - this would be vastly increased if there was no need for cash. Robbers would have to become IT experts.


Stucture of an email address @Service provider.country or organisation another@Yahoo.co.uk pddaviessies456@castle.org

What do you need to access email.  Email provider or ISP with a central mailbox facility.  User account or mailbox with user ID  User password


Disadvantages

Advantages of electronic mail

ƒ

1. Advantages over the telephone x People don't have to be in. The receiving computer will store the message until the receiver wishes to read their mail. x One letter can be sent to several users’ mailboxes at the same time. x Letters can be printed out so you have a hardcopy. x Can store the message for future use or edit it and return to sender x More confidential than fax systems

ƒ ƒ ƒ

Initial cost of buying hardware and software if only use it infrequently Possible way of spreading viruses Can’t send parcels.

2. Over the post x Security - Messages are automatically dated when sent and when received and read. - Less likely to be lost and backup copies can be kept. - Restricts unauthorised access with a good password system. x Will not be delayed by postal strikes or transport breakdowns so important contracts tenders can't be lost. x Faster delivery speeds (instantaneous). Delivers at weekends and evenings. x Once the hardware is installed Email is cheaper than the post (no stamp cost). 3. Over sending discs through the post. x Disc will need an operator at the other end to load it. x Disc can get lost in the post or damaged. x Still have delays in receiving the disc.

Advantages of the INTERNET • Easy communication with other people • Valuable learning resource because Internet skills will be needed for jobs in the future • Enables more people to work from home • A vast amount of information can be accessed • Up-to-date information can be accessed on-line without the need to await publication • Publishing documents on the Internet saves paper • A valuable resource for companies to advertise and conduct business

Disadvantages of the Internet • Much of the information isn’t checked and may be incorrect or irrelevant • A large amount of undesirable material, such as pornography, is readily available • Messages sent across the Internet can be easily intercepted and are open to abuse by others • Large telephone bills can easily be run up • Too much time spent on the Internet could result in a lack of face-to-face interaction with others and a loss of social skills • Going on-line runs the risk of hackers or viruses being able to damage your computer


Electronic Commerce - To most us this means selling goods and services over the Internet. Selling over the Internet offers many advantages for customers and retailers. Advantages x x x x x x x

Can buy 24 hours a day, 365 days a year No need to handle cash since all transactions are made using cards the transactions are automatic, saving staff costs the process is almost paperless the customer can print off an on screen receipt the delivery process can often be tracked online goods are often discounted because of lower retail costs

An electronic means of payment. e.g credit card or secure site.

A web page

An ISP (Internet Service Provider)

To establish an Ecommerce facility a firm would need the following;

A database of stock


The process of EFTPOS at the till: The retailer's main computer stores the stock control database that provides the electronic cash registers with data about each product. It also stores information about all completed transactions. 1. At the checkout, the operator scans the bar code of each item individually. 2. The stock file is queried using the item's code which retrieves the record for that item. 3. The price and description are displayed on the checkout monitors for the customer and operator to see. 4. The price of the item is added to the total and also printed on the till receipt. 5. The quantity of stock for that item is decremented by one. Automatic stock levels are maintained in this way. A minimum re-order level may be set so that the retailer may be alerted to items that fall below this level and a new order can be sent to their supplier. The retailer's card voucher (above) has the following details printed on it on completion of the transaction: x Date and time of transaction x Merchant Id x Transaction code x The amount to be paid x The card number, expiry date and issuing bank (payment by Switch)


Storage Sizes Bit

Kilobyte

Binary digit – 0, 1 8 bits make 1 byte 1024 bytes make 1 Kilobyte

Megabyte

1024 Kilobytes make 1 Megabyte

Gigabyte

1024 Megabytes make 1 Gigabyte

Byte

MEMORY RAM

ROM

Random Access Memory - temporary memory It is wiped clean when the power is switched off

Read Only Memory - permanent memory It is not lost when the power is switched off

Backing Storage Secondary (Backing) Storage Speed is less important than large storage capability. The most frequently used backing storage media are... * magnetic tape * magnetic disk * optical drives (CD-ROM ; DVD) Magnetic media Commonly used for backup and archiving Fast storage and access to data. Not portable Magnetic Hard Disk Stores more data than a floppy and is more robust. 50Gb. 1.44 mg Portable. Easily damaged Floppy disk Magnetic Tape

ZIP

Disk cache

Portable Special ZIP drive needed. Up to 250 Mb on one disc. (temporary, fast access e.g. storing web pages

Optical Disks CD-ROM/ DVD/ CDRW

Laser technology is used to read data. Stores more data portable. Expensive.

Large data files can be compressed for storage to save disk space Benefits of using ICT to help learning 

x x x x x x

Work can be edited Faster access to data. Work can be printed out in a variety of ways Accuracy of work is likely to be greater. Graphical interfaces more attractive so improved concentration span Programs are more interactive so different ways of learning.


DATA TYPES ID Number Integer Number

Name String

Postcode String

Date Of Birth Date

Cost Real or Currency

Y/N Boolean


Data Transmission Post

Satellitte

Infra red

Fax

Cable

Video Conferencing

Radio

Microwave

E-mail

Development in telephone communications Fax Data electronically transmitted over the telephone line. You don’t need the Internet or a computer to do this. Do not confuse this with email. It uses paper rather than electronic storage.

Mobile phones 1. WAP (wireless applications protocol) Phones -

Mobile phones that receive the Internet

2. Other Services available on most phones x x x x x

x x x x

Real-time talk Text messages Voice mail Alarm clock/time Reminders/ to do list

Advantages of mobile phone 1. Don’t have to be attached to a land line 2. Use out in remote areas

Change ring tone Record greeting message Display photos/ pictures on screen Radio

Disadvantages of using mobile phones  1. No service 2. No battery/ run out of credits 3. Fined if used when driving 4. Run up large phone bills 5. Get mugged

Video Conferencing (Tele-conferencing). With a small video camera fixed to your microcomputer, your image can be sent down the network to another user (and vice versa). Audio signals can also be sent. This means you can see and talk to another user if you have a microphone. Companies can set up meetings with eyeball-to-eyeball communication between people who are not in the same room, building or even country! Advantages

Disadvantages



x x x

Saving in time Savings travel costs Encourages ‘teleworking’

The pictures are of poor quality but with fast broadband connection the quality will improve


Features of software you need to know in detail x x x x x Spellchecker Checks for spelling mistakes

Mail merge Online thesaurus Online dictionary Headers and footers Pagination

compares word with online dictionary suggests alternative words does word counts add to users own dictionary grammar checks

Can’t check x x x x x x x x

Foreign words Common names Mixture of No and words e.g. postcodes. Words such as there and their which have different meanings. Inserts fields from a separate database into predefined positions in a prepared WP document displays alternative words of similar meaning e.g. good, better, great

x

look up meaning of words

x

enables same text at top or bottom of every page automatically

x

automatic numbering of pages by computer DTP


The human computer interface is what allows the user to communicate with the computer and is often called simply the user interface. The three main types of user interface are; 1. Command-driven 2. Menu-driven 3. Graphical or GUI (Graphical user interface)


Most modern micro computers operate through a GUI

Terms such as WIMP (windows, icons, menus, pointer) or 'desktop environment' are commonly used to describe these interfaces.

The user interface is the part of the system that communicates with the user usually via a screen. The main features of such interfaces are; W

Windows

To allow multitasking and display file structure

I

Icons

Are symbolic representations of files

M

Menus

To list appropriate facilities

P

Pointer

To select and choose the command or facility you want.

Windows display the file structure and enable all file within a folder to be displayed on screen other windows can also be displayed on screen at the same rime. Windows can be easily opened or closed using pointers. Modern computers also desktop features such as; x x x x

On screen help Customised user environments-favourites On screen assistants Tutorials

Advantages of a GUI • •

Don’t have to remember commands Intuitive easy to learn

Disadvantages of a GUI • •

Takes up memory Slows down processing

Voice recognition Microphone used to receive speech input. Speakers used for speech output. This is a VOICE driven system can help disabled people. The human factor is very important in the design of these systems and recent interest in expert systems and artificial intelligence has made Braille keyboards These are special keyboards such features as Natural language for blind or partially blind people interfaces more common place making machine human interfaces more user friendly. OCR Optical Character Recognition Some hand-held computers allow users to 'write' on the Problems: screen; scanning document x Users may speak different languages; x

local accents may not be recognised;

x

Some words sound the same - two, to, too

OMR Optical Mark Recognition e.g. lottery tickets, school registers






Health hazard

Cause Damage to the fingers, wrists and other parts of the body due to repeated movements over a long period of time. Fitting due to flickering screens.

Wrist and feet supports

Radiation

Exposure of radiation from monitors.

Screen filters

Eye strain

Looking at bright screens for too long.

Headaches

Looking at bright screens for too long. Staring at the same place.

Screen filters/ take breaks Take regular breaks/ screen filters Take regular breaks

Repetitive strain injury

Epileptic fits

Circulation problems Back problems

‘Sick building’ syndrome

Due to a poor posture or an awkward position while sitting at a computer. General health problems e.g. skin irritation, hypersensitivity reactions; eye irritation due to design flaws in the heating, ventilation, lighting and air conditioning systems.

Prevention

Screens to reduce screen flicker

Use adjustable chairs Better ergonomic design including lighting to reduce glare

Changes in working practises 

Employment issues  x Redundancies; some manual jobs have been lost x Some staff have needed retraining e.g. accountants need to use spreadsheets; typists use word processing packages; managers use database packages. etc. x New jobs have been created e.g. computer programmers, systems analysts

Changes in working practises x x x x x x x x

Use email Use the Internet Saving backups Virus scan discs Use of smart cards Use of software packages Videoconferencing Lack of personal contact

Teleworking - ‘People who work from home using computer networks’ Advantages to EMPLOYEES

Advantages to EMPLOYERS

Disadvantages

x

Savings in journey to work time

x

Savings on office space

x

x

x

Savings in travel cost

x

More flexible working hours

Retain skilled staff due to maternity or who have children at home – flexible working hours.

Loss of personal contact with colleagues

x

Initial cost of providing the hardware.

x

Cut down on absences due to babysitting problems




Computer crimes 1. Hacking - unauthorised access to confidential data Passwords which restrict access to data files

Encryption of files. If these are transmitted remember the receiving end must also have the codes to de crypt the data.

Prevention

Backup procedureskeep multiple copies off site; in fireproof boxes; see files for GFS etc

Restrict physical access to files e.g. smart cards to control entrance to rooms, voice or hand prints; retina scans; write protect notches on discs etc.

2. Spreading a computer virus These are programs introduced into computer systems which destroy or alter files by rewriting over data or by copying themselves over and over again until computer system is full and cannot continue.

Use diskless workstations on networks Control access to portable media and do not let users use own disk etc on the organisations system.

Use a virus scanning software and virus eradication program. Make sure this is kept up to date with the latest virus definitions – available from the Internet.

Don’t copy illegal software

Prevention

Don’t’ download unknown programs from the Internet straight to hard disc. Only use reputable sources.

Write protect media so can’t be written onto


3. Computer fraud – white-collar crime (NOT ’fraud’ by itself) x x x x x x x

Bogus data entry when entering data Bogus output -output may be destroyed to prevent discovery of fraudulent data entry or processing Alteration of files e.g. employee alters salary rate or hours worked Program Patching – introduction of an additional subroutine or code e.g. channel funds into a fictitious account or transmit codes to get free telephone calls Suspense accounts rejected or unreconciled accounts may be redirected into a colluding account. Blackmailing with threat of virus Deliberate data destruction to cause havoc and financial loss to a competitor

Monitor all programs and users actions should be monitored and logged. All users should be identifiable and all files capable of being audited keep online transaction logs

Companies must implement security procedures

Divide up programming tasks so no one programmer has responsibility for writing a program common in banks.

Prevention

Control access to hardware and software.

Auditing procedures to detect fraud

Often companies are unwilling to disclose crimes against them because

Computer crime is often relatively easy because

x

x

x

It could lead to loss of public confidence in the security of the data. Often their own security teams can be involved and this would again question their efficiency.

Users do not have a great deal of technical knowledge x Many external auditors do not have the expertise to trace programs but rely on printouts.

4. Software piracy is illegal copying but users do not get any technical support or upgraded versions. 5. Physical theft of computer equipment – use locking devices – restrict access to rooms with smart cards, hand or voice prints, retina scans 6. Deliberate theft of files- keep back up files - offsite - and in fireproof containers


The Computer Misuse Act 1990 makes it illegal to... x x x x

Gain unauthorised access to a computer's software or data (hacking) - including the illegal copying of programs. Gain unauthorised access to a computer's data for blackmail purposes. Gain unauthorised access to a computer's data with the intention of altering or deleting it. This includes planting viruses. copying programs illegally (software piracy)

A conviction may lead to a fine and a 5-year prison sentence.

Copyright Laws 1. It is illegal to copy a program from one floppy disc to another without the permission of the legal copyright owner 2. It is illegal to copy one program into more than one computer without a licensing agreement. Types of copyright crime Illegal copying: software piracy Purchasing one legal copy and loading it into several computers memory Transmitting software over telecommunications thus creating a copy. Software piracy is the unlawful copying, distribution and use of software. Each copy of software that is purchased is licensed for use on one machine.


NEVER use software brands e.g.

Microsoft Word PowerPoint Excel Access Publisher

= = = = =

Word Processor Presentation Software Spreadsheet Software Database Software Desk Top Publishing Software

NEVER use answers such as quicker, better, faster – unless you extend your answer with an explanation.


Year 11 Paper 1 Revision    Topics to Learn    1) Retail    POS System  e‐Commerce – buying and selling online – how this is set up    2) Banking    ATM  e‐Banking – how this is set up    3) Working    GUI  Changes in working practices – ‘electronic office’ ICT used to do most jobs  Teleworking‐ working at home  Computer crimes‐ how to prevent each one  Changes in work practice  Codes of conduct  Health & Safety    4) At Home    Applications used  Television services – teletext (published not interactive) interactive services eg internet,  email, booking tickets, games, voting etc  Control systems – alarms and greenhouse    5) At School    Applications used  Uses of ICT in school by students, teachers and admin staff     


Year 11 Paper 2 Revision    Topics to Learn    1) Applications  (Most of these will definitely be on your exam!)    For each of the set systems:  understanding what the system is, look at input, output and processing involved. Also learn about  advantages and disadvantages of each system  i Robotic and embedded control, ii Automatic stock control and order processing, iii Expert systems in  medicine, iv Booking systems    2) Data and Information    Information Processing Cycle, data collection and data logging‐  learn case studies of a commercial greenhouse and computerised weather station  Computer security – physical methods and using software  Data storage systems  Legislation – Computer Misuse Act and Copyright Law  Data Protection Act 1998 – Learn 8 principles and exceptions to the law    3) Database    Data storage  Learn definitions of Field, Record, File  Data Types eg text or string, integer, real, currency, date, Boolean etc.  Fixed length and variable length fields  Validation and Verification – methods for both    4) Hardware    Types of computer  RAM and ROM  Bits and bytes, also memory sizes in kilobytes, megabytes and gigabytes  Storage devices‐magnetic, optical and flash  Input devices eg mouse, keyboard, digital camera, scanner, microphone etc  Output devices eg printer, speaker, monitor, graph plotter etc    5) Networks    Types of networks – LAN and WAN, also understand peer to peer and client server systems  Advantages and disadvantages of a network  Network topologies ‐ Bus, Star and Ring set ups – set up, advantages and disadvantages of each  Backup systems and security used for networks     6) Software    Application software eg word processor, DTP, database, spreadsheet, graphics etc   Systems software eg operating system and GUI  Operating system – what is it and what are its main functions?  Learn different types of operating systems eg realtime and realtime transaction processing  Different user interfaces eg GUI, MS DOS, voice recognition, tetramouse, OMR, OCR    7) Systems Analysis    Analysis > systems design > Implementation > Testing > Maintenance > Evaluation (Learn all!)  Methods of implementation – direct, parallel running, pilot and phased  Remember all stages of your Year 11 Project where you were a systems analyst 


Definitions for GCSE ICT  You need to learn many definitions ‘word for word’    Account number  Found at the bottom of a cheque and read by MICR. It is the personal account  number of the account holder or holders. Eg 37465327  Actuator  In process control to carry out control actions on the process under control. If  the actuator is analogue, a digital‐to‐analogue converter is required.  Address book  List of email addresses  Administrator  Person whose job it is to ‘look after’ and administer a network. They will have  top level of access and give access rights to each user using ‘hierarchy of  passwords’  Analogue data  Can vary continuously within a range of values.  Analogue sensors  Measure variations in a control system eg air pressure, temperature, wind  speed, moisture  Analysis  Part of systems analysis. Analysis of existing data and data processing involved  in a system.  ADSL  ‘Asymmetric Digital Subscriber Line’ another name for broadband connection  to the internet. Don’t really need to learn this, just call it a broadband  connection  Alteration of files  Part of ‘computer fraud’ eg employee alters salary rate or hours worked.  ALU  ‘Arithmetic and Logic Unit’ which performs the calculations and logical  operations on data in a computer  ATM  Automated Teller Machine or Cashpoint machine, or ‘hole in the wall’  Attachment  Send a previously saved file with an email  Auditing procedures  Monitoring of processing activity to detect fraud.  Authorisation  What files you can see on a network and what you are allowed to do on the  network  Authentication  Password on a network.  Backing storage  Sometimes called ‘secondary storage’ Storage capacity on a computer   Backing storage media  The most frequently used backing storage media are magnetic tape, magnetic  disk, optical drives (CD‐ROM, DVD)  Backup  Security method to save files from a network or PC in case files get lost,  become corrupted or in case of criminal activity.  BACS  ‘Bankers Automated Clearing Service’ This is one method of using EFT  (Electronic Funds Transfer). Wages are usually paid through this method into  an employee’s bank account.  Barcode  Used in supermarket POS system. Contains country of origin code,  manufacturers code, product code and check digit. NOT price. It is scanned  with a laser scanner and each time check digit performs calculation to check  barcode and number are correct. Also used in library system.  Barcode reader  Using a small laser data from a barcode can be read and input to a computer.  Used for POS and in libraries  Batch processing  Data or programs are collected grouped and processed at a later stage eg  system  payroll, stock control and billing systems  Batch total  This is like hash totals but uses the number of records in processing run eg  payroll  Bit  Binary digit 0  1  Blackmail  Can be part of computer crime after hacking into private files  Bogus data entry  Entering extra data to a system to cause computer fraud.  Bogus output  Output may be destroyed to prevent discovery of fraudulent data entry or  processing  Booking System  System for making bookings eg theatre and concert tickets, holidays, flights 


Boolean  Braille keyboards 

Data type in a database which involves use of Yes/No or Y/N  Keyboards for partially sighted or blind. They have raised Braille letters on  keys.  Branch number  Found at the bottom of a cheque and read by MICR. It is a code for a bank  branch eg 46‐45‐90  Broadband  Gives the fastest connection to the internet. ADSL line. It allows music and  films to be downloaded.  Bulletin board  A forum to communicate with other people with a similar identity. It can be  work related, education related or fun related eg football bulletin board. You  can post emails as a new topic or add a ‘thread’ to an existing topic.  Bus or Ethernet  Workstations are connected to the main fileserver by cable and data can travel  network  in both directions to reach various nodes in the network  Byte  8 bits  CAD  ‘Computer Aided Design’ Can be used by architects to design a house, it needs  a very fast high spec computer. Software has specialist features eg 2D to 3D  conversion, ‘walk through’, rotation and zoom. Designs can go into CAM  software programs.   CAD/CAM lathe  Embroidery machines or lathes in DT  CAL  ‘Computer assisted learning’ Software programs designed to help with  interactive learning eg spelling programs, online tutorials, distance learning,  special needs software.   Calculated  Data type in database where a calculation is performed, eg automatically  works out age from date of birth   CAM  ‘Computer Aided Manufacture’ Can be used with controlled cutting machines,  which can cut materials eg clothes in clothing industry   Carbon copy emails  Send a copy of an email to more than one person at a time. Groups of people  can receive one email in this way.  Card copying  Crime of copying or ‘cloning’ somebody else’s credit card to make illegal  payments.    Carpal tunnel syndrome  RSI or ‘repetitive strain injury’ It starts as a tingling or numbness you've had for  months in your hand and wrist. Suddenly, a sharp, piercing pain shoots through  the wrist and up your arm. This is a painful progressive condition caused by  compression of a key nerve in the wrist.  Chat line  Allows ‘real time chat’ with anyone else who is on the internet at the time.  There are dangers from paedophiles and also of giving out too much personal  information.  CD‐ROM  Stores data up to 700Mb  CDRW  CD re‐write disks  Check digits  Used to check a barcode and to make sure it is correct. A small calculation is  carried out each time a laser scanner scans a barcode. This is a validation type.  Cheque clearing  This is the method of processing a cheque. It normally takes several days.  Cheque number  Found at the bottom of a cheque and read by MICR. It is the identification  number of an individual cheque. Eg 102201  Cheque processing  A cheque is a paper form that is issued by the bank that an account holder can  use to authorise payment to another person or organisation. An account  holder must write these details on the cheque for the payment to be  authorised.  Client server network  There is one fileserver which stores files and/or programs to be accessed by  other terminals.  COM  ‘Computer Output on Microfilm/Microfiche’ Output documents greatly  reduced on film. Needs a special reader to read them. Eg old newspapers in a  library  Compression  Large data files can be compressed for storage to save disk space. Compressed 


Computer fraud  Computer Misuse Act  1990  Computer programmer 

Concept keyboards 

Control 

Control access 

Controller  Control signals  Control Unit  Copyright Laws  CPU  Credit card 

Credit card fraud  Currency  Data  Database 

Data capture  Data logging 

Data Protection Act  1998  Dates  Debit card 

files need to be decompressed therefore the need for a decompression  program to be present when viewing files  Using a computer system to commit the crime of fraud. Sometimes this is  known as ‘white‐collar crime’  Makes it illegal to hack into data, use computer’s data for blackmail, altering or  deleting data after hacking into a system and copying programs illegally. Can  lead to 5 year prison sentence.  Someone who writes code in different computer languages to create new  programs or change computer programs. Will work as part of systems analysis  process.  Keyboard containing a continuous surface that can be defined as anywhere  from 1 to 256 keys. A wide variety of overlays are available from third‐party  manufacturers. One use of concept keyboards is to facilitate access to a  computer for the disabled.  Involves data from sensors, which will be sent to a computer program and  activate an external device eg a motor if needed. The software allows a flow  chart of the system to be created. Eg burglar alarms, environmental control of  central heating or greenhouse  A technique to prevent network crime. Access to a network controlled through  password system, and also by using security devices like fingerprint/ hand  scans, face, retina, iris scans, and access with smart card.  In process control a dedicated computer or a microprocessor‐based circuit  Computers in control systems will send out control signals to activated devices.  ‘Actuators’  The Control Unit controls all operations inside the computer and controls the  step by step running of programs.  Makes it illegal to copy programs, to copy to more than one computer without  a licensing agreement.  ‘Central Processing Unit’ the ‘brain’ of the computer  It lets you borrow money so cash does not have to be in the account at the  time of purchase. Used instead of cash or cheques to buy goods. People using  credit cards do not need to pay for their goods or services until the end of the  month.  Crime involving stealing details from someone else’s credit card to make illegal  payments. This is most widely used on the internet.  Data type in a database eg £ or $  Raw facts and figures, ‘meaningless’ on their own  ‘A database is an organised collection of related files of data’. Software used to  store data. It has searching and sort facilities. It allows export to other software  eg spreadsheet. It is used to do a mail merge.  Data captured or collected for a database eg questionnaires, barcodes,  surveys, forms, data logging etc.  The automatic recording of data as it is produced – eg temperature readings,  voltage levels, humidity levels These are recorded by an electronic device using  sensors  Makes holders or data responsible for holding that data. They must comply  with the 8 principals of the act. There are exemptions eg tax office,  doctor/dentist/ national insurance, DVLC etc  Data type in database. Usually we format to ‘short date’ eg dd/mm/yyyy  validation should make sure it is uk and not us date.   Cash does have to be in the account at the time of purchase. The transaction  amount is transferred electronically from the card holder’s bank account to the  retailer’s bank account a few days later. 


Desktop publisher 

Dialup  Digital camera  Digital data  Digital interactive  television  Digital sensors  Direct  Disclosure of crimes  Disk cache  Diskless workstations 

Distributed system 

Divide up programming  tasks  DTP 

DVD  E‐commerce  EFT  EFTPOS  Email  Embedded computers  EPOS  Encryption  Ergonomic 

Ethernet or Bus  network  Expert System 

Extranet  Evaluation 

‘DTP’ Software that has features of word processor but extra features to  handle clipart, wordart, shading effects etc. Better for documents that add text  and pictures eg Posters, birthday cards, calendars  Old fashioned internet connection through telephone line at slow speed of  56k. Phone could not be used at same time as internet is being used.  Photos can be downloaded from the camera and saved on computer  Can only have distinct values eg ‘on’ or ‘off’ on a light switch  Services available through a television eg TV channels, pay to view movies,  email, book holidays, play games, teleshopping and teleshopping  Measures on or off states eg circuit complete or circuit broken  Strategy for changeover in implementation stage of systems analysis. It means  dropping the old system and moving over directly to the new system.  Often companies will not disclose computer crimes against them for fear of  undermining public confidence in them  Temporary, fast access eg storing web pages  ‘Dumb’computers on a network that have no hard drive, or facility to use a  disk, eg floppy, CD, DVD. This prevents a virus being introduced to the  network.  Processing is carried out independently in more than one location, but with  shared and controlled access to some common facilities eg databases in  libraries  So no one programmer has responsibility for writing an overall program. This is  common when working in banks. Helps with security.  ‘Desktop Publishing’ Software that has features of word processor but extra  features to handle clipart, wordart, shading effects etc. Better for documents  that add text and pictures eg Posters, birthday cards, calendars  A DVD disk holds 4.7Gb of data   ‘Electronic Commerce’ or online buying and selling  ‘Electronic Funds Transfer’ Way banks move money electronically between one  bank and another over computer networks.  ‘Electronic Funds Transfer Point of Sale’ A system where banks can move  money between one bank and another electronically over computer networks.  An electronic message transfer system  Devices with computer technology inside of them. Many household devices eg  washing machine, television, burglar alarm etc.  ‘Electronic Point of Sale’ where the POS system has an electronic terminal so a  customer can pay by debit card.  Coding data at one end, sending it and decoding it at the other end  Design where things are built to shape the human body. Ergonomic design  used in offices and work places helps reduce illnesses like RSI and ‘sick  building’ syndrome.  Workstations are connected to the main fileserver by cable and data can travel  in both directions to reach various nodes in the network  A knowledge based system that attempts to replace a human expert in a  certain field.  A user interface links user questions to an inference engine (rule  based system), which interrogates the database of knowledge to provide  results. Used at times in hospitals to support doctors.  A private network that can be accessed from the Internet using a username  and password – eg accessing school network from home  Last stage of systems analysis. Look at outcomes of new system, how staff  have responded, customer satisfaction and involves keeping logs of  breakdowns and errors. Evaluation could prove a new system is unsatisfactory. 


Face recognition  Favourites  Fax 

Feasibility study  Field  File  Fileserver 

Fingerprints  Fixed length  field/record  Flash drive 

Floppy disk 

Format 

Format controls  FTP  Gigabyte  GIGO  Graphics tablet  Graph plotter  GUI  Hacking  Hash totals 

HCI  Headers and footers  Hierarchy of passwords 

Home banking 

Security to give biometric access to a computer room. Involves scanning the  features of the face.  A place in the web browser to save favourite websites. It stores the url and  acts as a short cut to the websites.  Data electronically transmitted over a telephone line. You don’t need  the  internet or computer to do this. Do not confuse with email. It uses paper  rather than electronic storage  Part of systems analysis. Involves investigating options and producing a  feasibility report. It should contain costs and benefits of the whole system.  A collection of related data in a database  An organised collection of related records in a database  This is a computer attached to a network that has the primary purpose of  providing a location for the shared storage of information (such as documents,  sound files, photographs, movies, images, databases, ect.) that can be  accessed by the workstations that are attached to the network.  Security to give biometric access to a computer room. Involves scanning  fingerprints.  Each field in database of fixed length and each  record a fixed number of fields  Another name for a memory stick. A newer form of temporary storage, more  robust and holds a lot more than a floppy. Works with flash memory. Typically  can be 2 or 4 Gb.  1.44Mb Portable and easily damaged. Please note hardly used these days. Lots  of new PCs don’t include floppy drives and people use memory sticks rather  than a floppy.  Preparing data so that it shows correctly in a database or spreadsheet eg short  date = dd/mm/yyyy. Also make sure set for UK format and not American  format ie mm/dd/yyyy  Set these up when creating files eg enter number as 99.99 or date as ‘short  date’ dd/mm/yyyy  ‘File Transfer Protocol’ is the protocol that lets you upload and download files  for a website.  1024Mb, a thousand million bytes  ‘Garbage in garbage out’ used to explain setting op a database correctly. If  poorly set up, poor results come out.  Used for graphics packages to give a more natural ‘feel’. User draws on tablet  and results appear on screen. Eg could be used for tracing maps  Used to produce high quality graphics for CAD. See also ‘Plotter’  Graphical User Interface (remember ‘WIMP’ Windows, Icons, Menus and  Pointer) eg Microsoft Windows XP or Vista   Accessing a network or data without permission. Another name for  ‘unauthorised access’  Formed by adding together a series of records. During processing the  computer will add up the field numbers and compare it with the stored total if  they do not match an error has occurred.  ‘Human‐computer interface’ means the ways in which a human communicates  with the computer via a user interface.  Enables same text at top or bottom of every page automatically  Access to a network by using username and password. Also each user is only  allowed to use the software or get access to files that they need to use. An  administrator will have top level of access.  Customers can access their bank account details from home across the  internet. 


HTTP 

‘Hypertext Transfer Protocol’ is the protocol that allows you to communicate  with the internet and view websites.  Human‐computer  (HCI) means the ways in which a human communicates with the computer via  interface  a user interface.  Illegal software  Software you have not bought and do not have a licence to use. Licence could  now be out of date, making the software now illegal.  Immediate Access Store  Or ‘Main Memory’ holds the programs currently or awaiting execution  Implementation  Stage in systems analysis where new system is introduced. It can involve  different changeover strategies eg direct, parallel running, pilot and phased  Information  Processed data  Integer  In database whole numbers data type eg 256. Used for keyfields  Interactive processing  The user has to be present and program cannot proceed until there is input  from the user eg menu on ATM  Interactive services  Such as those found on the internet allow you to send back information.  Internet  A Wide Area Network or ‘Network of Networks’ or ‘Global Network of  Computers’  Intranet  An internal private network eg a school network  Iris scan  Security to give biometric access to a computer room. Involves scanning the  iris of the eye. Not to get confused with ‘retinal scan’ which scans another part  of the eye.  ISDN  ‘Integrated Services Digital Network’ a faster than ‘dialup’ connection for the  internet 112k (56k for dialup). Don’t need to learn what it stands for just learn  ISDN.  ISP  Internet Service Provider‐ company that provides communication software for  internet access and services eg Freeserve, AOL, Pipex, Demon, Virgin etc.   Itemised bill  A printed bill given at supermarket for example. It gives lots of information eg  date of purchase, name of cashier, how paid, change given, card number, VAT  number, cost of each item, total.  Joystick  Used on PCs mainly for games playing  Keyboard  Allows characters to be input into a computer  Keyfield  Uniquely identifies an individual record in a database  Kilobyte  1024 bytes, a thousand bytes  Kimball tags  Pre‐punched tags affixed to goods in a clothes shop for example, contains size  and style data that speed up stock control. They are small, rectangular  cardboard tags, removed at POS and tags might be placed on a spike near the  till. At the end of the day the tags are collected and placed in a card reader to  input data.  Knowledge  Information which has rules applied to it  LAN  Local Area Network‐a smaller network contained within a room or building eg  a school network  Laptop computer  Portable computer much favoured by businessmen, but used by all sorts of  people today  Light pen  User writes on screen with a pen, Used for some graphics CAD or art packages  Loyalty card  Given out by supermarkets to give points, offers or cash gifts to loyal  customers. Used by stores to retain customers, find out about sales patterns  and to target customers  Magnetic Hard Disk  Fast storage and access to data. Stores more data than a floppy and is more  robust. Typically could store 50Gb of data.  Magnetic strip   A card with data recorded onto a magnetic strip, are swiped through a card  reader, and data is read off it  Magnetic tape  Commonly used for backup and archiving. Used to backup a network  automatically. 


Mail merge 

Mainframes  Main memory  Maintenance 

Mark‐sense reader  Master file  Megabytes  Memory stick  Micro computers  MICR  MIDI input  Modelling  Modem  Monitor  

Monitor  Mouse  Multimedia 

Multi‐access on‐line  Multiprogramming  Multi tasking  Network  Network topologies  Newsgroup 

Node  OCR 

Offline processing  OMR 

Inserts fields from a separate database, into predefined positions, into a word  processed document. It allows the same document to be sent to many  different people.  Large central computers (size of rooms) to run a large wide area network  (WAN)  Or ‘Immediate Access Store’ holds the programs currently or awaiting  execution  An essential part of systems analysis. When the new system is in full operation  it must be reviewed at regular intervals to monitor performance.  Documentation has to be kept up to date. Changes might need to be made if  eg the government introduces new tax laws.  OMR eg school register, exam multiple choice questions and lottery   Permanent file kept up to date by applying transaction file  1024k, a million bytes  A newer form of temporary storage, more robust and holds a lot more than a  floppy. Works with flash memory. Typically can be 2 or 4 Gb.  The more old fashioned name for a PC  Magnetic Ink Character Recognition eg used by banks to read cheques  Musical Instrument Digital Interface. Recording the sound patterns of musical  notes using different instruments.  Using a spreadsheet to perform ‘what if’ type investigations. If numbers or  values change, what will be the results?  A device needed for analogue to digital conversion and back again ie modulate  and demodulate.  Screen displays composed of a large number of pixels which display dots in  different colours. High powered graphics are used if a graphics card is fitted.  Some have TFT (Thin Film Transistor) screens, LCD Liquid crystal display and  thin plasma screens.   All network programs and users actions should be monitored and logged. This  is part of auditing procedures to try and stop computer fraud and misuse.  Used on PCs. Directs a screen pointer. Used in a GUI (WIMP) environment  Can handle sound and video files. Animation and transition effects, automatic  timing effects. Used in presentations, but also applied to televisions and  computers.  Many users linked by workstations to a central computer such as in a network.  Holiday or airline booking, one user is locked out to prevent double booking  Ability to run many programs apparently at the same time eg In mainframe  computers each job is allocated ‘time slice’ in turn  The ability to hold several programs in RAM at one time but the user switches  between them eg using GUIs  Computers which are linked together  How we arrange our network  A forum to communicate with other people with a similar identity. It can be  work related, education related or fun related eg football bulletin board. You  can post emails as a new topic or add a ‘thread’ to an existing topic.  A device connected to a network, such as a computer or router  Optical Character Recognition eg scans words and converts to text on  computer. Used on palm tops, and used to copy hand written gas and  electricity metre readings for billing purposes.    Processing which is done away from PC eg batching together clock cards, filling  in OMR cards  Optical Mark Recognition eg school register and lottery Sometimes called 


Online booking system  Online dictionary  Online processing  Online thesaurus  Operating systems 

Optical disks  Pagination  Palmtop computer  Parallel running 

PDET  Peer to peer network  Phased 

Peripherals  Pilot 

PIN  Plotter  Portable media  POS  Presence checks  Printer  Program Patching  RAM  Random file  Range checks  Real  Realtime 

‘mark‐sense’  Might be used for theatre and concert tickets, holidays and flights. They can be  booked through the internet.  Look up meanings of words  Processing performed under direct control of CPU whilst user remains in  communication with the computer  Displays alternative words of similar meaning eg good, better, great  An operating system is a program or set of programs which control the  hardware and allow user programs to run. They should be reliable, efficient,  small and maintainable   Laser technology is used to read data  Automatic numbering of pages by computer, used in Word processor or DTP  A very small portable computer designed to be used in the palm. Smaller than  a laptop.  Strategy for changeover in implementation stage of systems analysis. It means  running the old system alongside the new system. Eventually if the new system  proves successful the old system will be dropped after many checks.  Portable Data Entry a calculator sized device that reads bar codes  All stations in network have equal status. All terminals usually intelligent and  so applications may be stored on different computers and accessed by all.  Strategy for changeover in implementation stage of systems analysis. It can be  used with direct or parallel running changeover. Only some files eg some  customer accounts should be computerised to check the system.  Devices that can be connected to a computer and controlled by it. These can  be input or output devices.  Strategy for changeover in implementation stage of systems analysis. It can be  used with direct or parallel running changeover. It means only using a small  part of company or organisation to test the new system eg accounts  department only  ‘Personal Identification Number’ used to authorise a transaction using an ATM  (Automated Teller Machine), or at POS using ‘chip and pin’ system.  A type of very large printer used for posters and architects drawings. Used with  CAD.  Peripheral storage devices like floppy disk, CD writer, DVD writer, memory  stick, ZIP streamer, portable hard drive.  Point Of Sale involves scanning barcodes with a laser scanner eg used at  supermarkets  There must be a character present in a particular place on a database. . This is  a validation type.  Used to create ‘hard copy’ Laser printer good quality and quiet, Inkjet printer  cheaper slow, can use colour  Introduction of an additional subroutine or code eg channel funds into a  fictitious account or transmit codes to get free telephone calls  ‘Random Access Memory’, memory used ofr temporary storing programs and  data. It is wiped clean when the power is switched off.  In database gives very fast access. To individual records without  having to  access other records first eg car registration or train timetables  Data is between stated ranges eg must be between 1 and 1000. This is a  validation type.  In database number data type with decimal points eg 4.5  This means being online at the same time eg chat lines work in realtime where  both people are online at the same time, where email does not have to involve 


realtime communication. Email can be received and sent at any time without  the receiver having to be online at the time.   Realtime systems  Control where data from sensors is processed immediately. Timing is critical, a  ‘matter of life and death’ eg air traffic control, nuclear power plants, oil  refining, chemical processing  Realtime transaction  Transactions completed online eg holiday and airline booking systems. Timing  is not critical like in realtime systems. If two users are booking same thing one  will be locked out to stop double booking  Record  A collection of related fields in a database  Repetitive strain injury  ‘RSI’ can be caused by constant use of a computer. Usually affects wrists or  neck.  Retinal scan  Security to give biometric access to a computer room. Involves scanning the  retina of the eye. Not to get confused with ‘iris scan’ which scans another part  of the eye.  Ring network  The Cambridge ring has no host computer and none of the nodes need to have  overall control of access to the network. Messages in the ring flow in one  direction from node to node. Messages addressed from one node to another  are passed around the ring until the receiving node is ready to receive it.  ROM  ‘Read Only Memory’ is a permanent non volatile memory which stores  programs which cannot be overwritten. They can be ‘read only’ and are not  lost when power is switched off eg system programs, GUI  RSI  ‘Repetitive strain injury’ can be caused by constant use of a computer. Usually  affects wrists or neck.   Scanner  Scans and inputs images from a printed sheet. Hand held or flat‐bed.  Search engine  Allows you to search www for any topic, and each page has links to another  and so on.  Secondary storage  Sometimes called ‘backup storage’. Storage capacity on a computer  Sensor input  Digital readings eg light, heat movement, heart beat are measured and sent as  analogue signals to be used as input for a control system  Sequential file  In database sorted in order of the keyfield file  Serial file  In database unsorted file usually a temporary file  ‘Sick building’ syndrome  An illness caused by working in an environment with poor ergonomic design  and lighting with a lot of glare.  Simulation Model  Software that represents a real life situation. Sometimes used if dangerous in  real life eg training pilots, or if its expensive eg economic forecasting  Single‐user on‐line  Provides for interaction between the job and the user, which may influence  the course of processing eg word processor  Sound output  Using speakers, useful for music, voices and sound effects for games. Also used  on MIDI keyboards  Spellchecker  Compares words with an online dictionary and suggests alternative words. It  does word counts and allows users to add words to the dictionary. It does  grammar checks.  Star network  Each node is connected to a CPU at the centre.  Popular topology for a WAN.  Messages pass through host which interconnects different devices on the  network. The central host switches messages point to point.  Stock Control  The task of recording and maintaining stock levels  String  In database text data type  Smart Cards  Programmable plastic cards ‐ they have chip on front of them. Can be used for  security to give access to a computer room. Smart cards are also being used for  various payment systems as an alternative to cash eg Mondex.  Speakers  For sound output, useful for music, voices and sound effects for games. Also  used on MIDI keyboards. Used with teleconferencing 


Spreadsheet 

Software piracy  Store card 

Systems analysis 

System design  Technical  documentation  Teletext 

Terminal 

Testing 

Touch sensitive menus  or screens  Transaction file 

Transcription errors  Transposition errors  URL  User documentation  Validation  Variable length fields 

Verification 

Video conferencing 

Virtual reality input  Virus 

Software used as a calculator. Stores formulas and data.It allows ‘what if’  calculations, and a variety of output formats eg graphs It can be used to do  mail merges  Illegal copying of software  A type of credit card which belongs to a large store. Customers can use this to  buy goods electronically at POS. Eg a Burton’s store card, or a Marks &  Spencers’ store card.  Analysing a process or procedure to find a better way of making it work. This  involves analysis, systems design, implementation, testing, maintenance,  evaluation. A person who does this job is a ‘systems analyst’  Stage of systems analysis which involves detailed design of proposed new  system.  Documents on how technicians should maintain a new system after  implementation in systems analysis.  Information service using adapted television sets. The information is broadcast  along the normal television signal. BBC teletext is called Ceefax. The system is  free but is non‐interactive.  A computer attached to a network that is used to enter data to a network. It  can be a PC or a ‘dumb’ machine that just allows data to be typed into the  network.  This is an essential part of systems analysis. Programs are tested individually  and whole system interaction is tested to. If modifications are made to a new  system there will be re‐testing too.  Used in places like McDonalds, where all of the prices can be input into POS by  pressing a coloured key for each item bought.   A temporary file for storing data. It contains detail of all transactions that have  occurred in the last period of processing eg a file in a supermarket showing a  day’s takings at POS.  Typing errors, typing wrong character by accident  Keying in wrong order eg 56789 instead of 57689  ‘Uniform Resource Locator’ just another name for a web address, which begins  with www.   Documents on how users should use a new system after implementation in  systems analysis  'The process of ensuring data is valid and legal' Making sure that data is  sensible – eg within a defined range <10  Each field in database of different lengths with each field terminated by a  marker (*) and each record terminated by a marker. Can contain a different  number of fields   'The process of ensuring data has been copied over correctly from one medium  to another' Double checking that data has been entered correctly – eg proof  reading, being asked to enter password TWICE to make sure it has been typed  correctly  Sometimes called ‘Tele‐conferencing’ With a small video camera fixed to your  PC your image can be sent down the network to another user (and vice versa).  Audio signals can also be sent. This means you can see and talk to another user  if you have a microphone. Companies set up meetings with eyeball‐to‐eyeball  communication between people who are not in the same building or even the  same country.  Hardware devices eg digital glove are worn by the user, whose movements are  sensed and used as input. A VR helmet may be used.  A program introduced into a computer with the intention of causing damage or  inconvenience eg the Melissa virus 


Virus definitions  Virus eradication  Virus scanning  Voice recognition  Voice prints  WAN 

WAP  Web cam  Web publishing  software  ‘White collar crime’ 

WIMP  Word  Word processing  Write protect  WWW  Unauthorised access  ZIP    

The latest definitions of viruses available to keep virus scanning software up to  date  After finding any viruses present on your computer or network, this part of the  software will remove them all.  Software that searches a computer or network for viruses. For it to be effective  it should be updated with latest ‘virus definitions’  Using a microphone to receive speech input, and speakers for speech output,  this is a voice driven user interface.  Security to give biometric access to a computer room. Involves scanning voice  patterns.  Wide Area Network‐ ‘a network of networks’ bigger networks covering cities or  linking various external networks via gateways eg internet or multi‐national  companies  ‘Wireless applications protocol’ Mobile phones that receive the internet  Allows video conferencing across the internet  Software used to build websites and to upload finished web pages through FTP  into web space. It includes lots of word processing features and ability to add  graphics and hyperlinks.  This is another name for ‘computer fraud’. It could be committed by anyone  who uses a network and suggests that its hard to know often who to suspect.  Sometimes its an employee with a grudge against the company or institution.   Short for Windows, Icons, Menus and Pointer, and is an easier way to  remember the main features of a GUI (Graphical User Interface)  NB not the software! Largest number of bits a processor can handle at one  time eg a 64 bit processor can handle 64 bits  Software application to enter and process text. Good for text based documents  eg letter, essay  Media that can be read only and cannot be written onto  ‘World Wide Web’ Part of the internet that allows you to browse websites,  that usually begin with ‘www’  Accessing a network or data without permission. Another name for ‘hacking’  Portable special ZIP drive needed. Up to 250Mb on one disc. 


Tips for GCSE ICT Exam    Dates    The dates for the WJEC GCSE ICT exams are as follows:    1) Paper 1 = Monday 21st June 2010 at 9.15 am          Higher Paper (A*‐D) = 1 hour 30 minutes         Foundation Paper (C‐G) = 1 hour     2)  Paper 2 = Monday 28th June 2010 at 1.40 pm          Higher Paper (A*‐D) = 1 hour 30 minutes         Foundation Paper (C‐G) = 1 hour    NB Don’t plan on just revising for each exam separately. There is a certain amount of overlap  between the knowledge needed for both papers. You need to revise for Papers 1 and 2 in their  entirety and don’t just revise for Paper 1 for the first exam, and for Paper 2 for the second exam.  You could for example find questions on data and information, databases, data logging,  spreadsheets, software, networks, control etc. on both or either of the papers.     Use the Revision notes provided mainly for each exam when the exam is coming, but also look at  the Revision notes for the other paper too. (Not in as much detail though!)    Important     1) Don’t ever answer questions with one word answers, ‘faster’ ‘quicker’ or ‘more efficient’. You  must explain fully what you mean or no marks will be given.    Eg    A broadband internet connection is faster than either a ‘dial up’ or ISDN connection.    A person can usually get their money quicker by going to an ATM to get cash, than going to the  bank and queuing up.    Doing a search on a database is usually a more efficient way of finding a particular record than  searching through paper files in a filing cabinet.    2) On Paper 2 you must learn all of the systems in the ‘Applications’ section in detail. These are  robotic and embedded control, automatic stock control and order processing, expert systems in  medicine, booking systems. You can guarantee that there will be a number of questions on the  paper for these topics. These are specialist topics on Paper 2 for this year.    Concentrate in each system at understanding what the system is, look at input, output and  processing involved. Also learn about advantages and disadvantages of each system. 


GCSE ICT Revision Guide  

This is a revision guide for GCSE ICT

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