Input Process Output Keyboard Mouse Scanner Digital camera
Input Process Output • Keyboard • Mouse • Scanner • Digital camera • Light pen • Graphics tablet • Sensors Backing store • Monitor • Speaker • Hard disc • Floppy disc • CDRW • Flash memory • Plotter • Printer
Computers linked together
• Faster processing • Saves on storage space • Password protection to files • Initial cost of purchasing computers • Over reliance if a power cut • Staff retraining
Country of origin Check digit Manufacturers Code Product Code Exam hint! Make sure you say CODE not Name. e. g. Manufacturers code NOT Manufacturers Name Makes sure the barcode is scanned in correctly and details of the correct product is displayed
Bar code scanner Screen Weighing scales Printer for receipt Keyboard Speaker Card reader
Stock code Desc. Price 26543 Beans 0. 59 No in stock No sold Re -order Supplier level 100 50 35 Heinz Stock code No sold today 26543 Stock code Desc. Price 26543 Beans 0. 59 20 No in stock No sold Re -order Supplier level 100 70 35 Heinz
• Faster service at POS • Fewer mistakes • Itemised bills • Variety of ways to pay • Buy One Get One Free • Power cuts • Damaged barcodes causes delays • Embarrassment with faulty card readers
• Retain customers • Sales patterns • List of spending habits Touch sensitive screens
Online shopping • Buy goods online 24 hours a day 365 days a year • No needing to travel so save time
• Internet Service Provider • Database of stock • Web page • Secure electronic payment For company Reach wider market For customer • 24 hour / 365 day shopping I S P Credit or debit card • Don’t have to leave home (disabled) • Savings on travel and time costs
Disadvantages of online shopping • Online transactions require users to enter a debit or credit card number before a purchase can be completed. There is a danger of these numbers being intercepted by hackers during transmission and used to make unauthorised purchases. The use of encryption and smart cards and paypals can help to protect against this. • 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 and services that they will never receive as well as damaging the reputation of a genuine business. • It is much easier for a business to gather information about its rivals by simply accessing their web sites — this can make it much harder to remain competitive.
Banking · Cheque processing · EFTPOS Electronic Funds Transfer at Point Of Sale · ATMs · Credit cards · Debit cards · Smart cards MICR Magnetic Ink Character Recognition. Bank of Monee Date…… Pay………… Amount………………. . …………… A N Other 46 -45 -90 37465327 102201
Services available at an ATM · Cash · Change PIN No · Check balance · Transfer money between accounts · Printed mini statement · Order cheque books and statements · Select language. · Order theatre tickets · Deposit cash Problems which could occur when customers use ATMs · Could be attacked/security · Could forget PIN · Wrong amount of money issued · Card could be retained • Card might get damaged Advantages of ATMs; For the customers · Provide 24 -hour services · Access ATM’s in many locations · Cuts down on queues in banks / faster service for customers (Not shorter queues at the ATM) For the bank · Save on staff costs · Allows staff to concentrate on other work e. g. selling mortgages or other · Services/increase sales · Increased security
Card crimes Account No Spending limit Prevention Stealing cards at ATMs Do not write down PIN numbers Do not let anyone see you typing in your Pin number Stealing debit and credit cards Photos on cards Lower amount that can be spent with cards before seeking authorisation Details of stolen cards on POS Credit card fraud on the Internet and their misuse Use agreed words on some sites Use a secure service Encryption Card copying Programmable smart cards to make data difficult to copy Use of holograms to make cards difficult to copy.
Homebanking Customers can access their bank account details from home across the Internet Advantages · Customers don’t have to leave home/ saves time · Savings on postal or travel costs · Transfer money or pay bills from home · Pay bills anytime · Instant balances Problems · Hacking of credit card / debit card details by unauthorised people who might misuse the data. · Have to pay telephone charges whilst online. · Lack of personal contact; - may not understand the system and you have no one to help.
Online booking systems • Allow Internet users to check the availability of and book things like: • Theatre, cinema and concert tickets • Seats on coaches, trains and aeroplanes • Hotel rooms • An online booking system is essentially a web site that can be used to access a remote database
The Internet What do you need to get the Internet • A computer with a modem and access to a telephone line is needed. • Faster connection is possible with a special type of digital telephone line called an ISDN line which doesn’t need a modem. • Broadband: Very high speed digital lines • Find an Internet Service Provider (ISP)
Services available on the Internet: Email Sending messages to other internet users Teleconferencing Communicate visually with other Internet users. E-commerce Buy goods Tele-banking Manage banking transactions, pay bills, transfer money between accounts etc Web publishing Create and administer your own websites for specialist interests, etc. . . Chat lines Send messages on-line to some strange people. Broadcasting Music and video Downloading Software, drivers and other files
Browsers • To browse or ‘surf’ the Internet a browser program is required • use search engines to search for information by entering keywords
Messages sent -between two computer -across networks -across the Internet • Address books list of email addresses • Attachment a stored file which is attached to a message and sent with it • Carbon copy emails an email is sent to more than one person at the same time
Sending and receiving is faster More secure because password protected and unlikely to get lost People do not have to be in to receive it One letter can be sent to many users mailboxes at the same time Messages are dated when sent and received an automatic response given. Over sending a disc Needs to be reloaded at other end Discs can get lost or damaged Slower to send and therefore receive
Dangers of the Internet Hackers • Firewall software Viruses • Often spread via e-mail • Virus checking programs • Don’t open emails from people you don’t know Undesirable material • Software to block sites • Adult supervision • Filtered service from ISP Paedophiles • Do not give personal details to strangers • Do not go into private rooms with strangers • Never arrange to meet anyone you chat to.
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
• Do not tell anyone your password • Change password regularly • Virus scan all discs • Do not misuse the Internet e. g email, chat rooms • No hacking • Do not steal hardware / software
8 User Interfaces 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; Command-driven Menu-driven Graphical or GUI.
The main disadvantage of command-driven interfaces is that they are very difficult to use if the user is a beginner or doesn’t know the correct commands. Command-driven systems can be very unfriendly and confusing for noncomputer experts to use. The correct commands to copy the file are typed in by the user at the keyboard The operating system displays a message to confirm that the command has been carried out successfully.
Menu-driven user interfaces Menu-driven systems offer the user lists of options which they can select by pressing a particular key on the keyboard. The main advantage of menu-driven systems is that they are easy to use. The main disadvantage of menu-driven systems is getting to one particular option can often involve working through many different menu screens.
In this example a menudriven user interface has been used to copy a file called fred. txt to a user’s floppy disk.
• • W indows I cons M enus P ointers • On screen assistants • On line. Tutorial • Favourite settings Advantages • Don’t have to remember commands • Intuitive easy to learn Disadvantages • Takes up memory • Slows down processing
Word Processing; Entering and processing text using a computer Letters Desktop publishing software In addition to word processing features it has extra features to handle images such as clipart , word art, shading effects, rotating text and frames such as text boxes. Posters School projects Multimedia Can handle sound and video files Animation and transition effects Automatic timing effects School presentations e. g. showing previous school trips to parents Web publishing software *sound files video files *has hyperlinks to other pages *bookmarks so it can jump to different parts of the page School website
· 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 · A field is a collection of related data
is raw facts and figures is processed data is derived from information which has rules applied to it
ID Number Name Postcode Date of Birth Cost Y/N
• Saves memory • Faster to type in • Less chance of errors
Abaerun • Hte instead of The • 123456 132465
‘Process of checking that data has been copied over correctly from one medium to another’ TRANSCRIPTION ERRORS Typing errors. Typing in the wrong character by accident eg 2 instead of a 7 TRANSPOSITION ERRORS Swapping i. e. keying in in wrong order e. g. 56789 instead of 57689 These can only be checked by Double entry keying in and cross checking a careful visual check Scanned in data e. g. barcode Parity checks Process of checking data is SENSIBLE and REASONABLE Range checks Between 1 and 999 Input masks ##00 0## Format checks 99/99/99 Check digits
1. Physical protection of the data. ·Keep BACKUP copies in a safe place ·Put the write protect notch on your disc/ make hard discs read only ·Keep copies in fireproof boxes or computer discs in fireproof rooms. ·Lock computers to desk
Advantages of a spreadsheet • Accuracy of calculations • ‘What if’ investigations • Draw graphs and other output forms • Save the formulas and data • Automatic recalculation if data changes NOT does calculations for you!!!
Advantages Simulation model A program that models a real world situation • Computer have to calculate many large formulas quickly • Display as graphics • Traffic flows • Dangerous and expensive to do test in real life • Supermarket flows Disadvantages • Flight simulation • Not 100% accurate • Virtual reality • Requires powerful computers and complex programming
Software protection of data A. Unauthorised Access/ hacking 1. Hierarchy of Passwords Identification User Name Authentication Password Authorisation What files you can see and what your allowed to do Read only write only or read and write 2. Encryption Coding data at on end sending it and decoding it at other end. 3. Voice / hand prints 4. Smart cards To access rooms and computers B Spreading of viruses ·Write protect media so can’t be written onto ·Don’t copy illegal software ·Use a virus scanning software and virus eradication program. Make sure this is kept up to date with the latest virus definitions and fix tools ·Don’t download from the Internet straight onto hard disk
A security company has installed the following control port to monitor and control a household security system SECURITY LIGH MOTOR ON GATE SIREN DOOR SENSOR PRESSURE MAT 1 2 3 4 5 0 0 Write down the display of bits should the following situations occur. a) A burglar has stepped onto the PRESSURE MAT and a SECURITY LIGHT comes on. 1 2 3 4 5 1 0 0 0 b) A burglar has opened the FRONT DOOR and the SIREN comes on. 1 2 3 4 5 0 0 1 1 0 c) A burglar has opened the FRONT DOOR and a SECURITY LIGHT is on and the MOTOR ON GATE is activated. 1 2 3 4 5 1 1 0 1 0
Write a sequence of steps needed to keep the temperature of the greenhouse between 200 C and 22 0 C, and keep it there, using only the heater and thermostat. • If temp on thermostat > 220 C turn off heater • If temp on thermostat < 200 C turn on heater • If temp between 200 C and 220 C do nothing / leave alone Advantages of datalogging Types of sensors • 24 hours/365 day monitoring • Heat • Human do not have to be there • Light • Accurate readings • Pressure • Accurate recordings • Moisture
• New Jobs e. g. programmers • Retraining e. g. accountants using spreadsheets • Jobs lost e. g. filing clerks Teleworking ‘working from home using computer networks’ • Saves travel time • Saves journey to work costs • Don’t lose skilled labour • Flexible working hours • Savings on office space and rents
Repetitive Strain Injury Back Ache Epileptic fit Radiation Eye Strain Poor circulation Headaches Sick Building Syndrome
Air conditioning Shading from sunlight blinds etc. Adjustable chairs Take regular breaks Foot rests Wrist rests Take regular breaks Walk around Screen filters to reduce glare and flicker
W A ireless pplications P rotocol Advantages • Use anywhere • Don’t have to be attached to a landline Disadvantages • No service • Battery fails/ no credits • Fined if used while driving • Potential health risk • Get mugged Services • Text messages • Voice mail • Alarm clock • Games • To do list • Calendar • Send Photos
• Pay to view (sport / films) • Games • Email • Interactive choice • Televoting • Teleshopping • Book holidays • Email Back to START
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