General Purpose packages

1. General Purpose packages What is a General Purpose Package (GPP)? A piece of software that allows the user to provide their own input to achieve many different types of output. E.g. A spreadsheet package can be used to store personal accounts or create bus timetables. This is unlike a single purpose package, such as a computer game, which can only be used for one task, I.e. playing the game.

2. General Purpose packages • What is an INTEGRATED PACKAGE? • A single piece of software containing two or more GPP’s. • What are the advantages of an integrated package? • Costs less than buying all the packages individually. • Easy to share information between different packages. • Human Computer Interface (HCI) is usually the same for each different part of the package, e.g. commands used to print, save, change styles etc. • What are the disadvantages of an integrated package? • Can use more memory than individual packages. • Each package has less features than an individually bought package.

3. General Purpose packages What is ON-LINE HELP? Menus chosen when using software on the computer, giving ideas on how to do certain tasks. What are ON-LINE TUTORIALS? A series of step by step lessons performed on the computer, which help the user to learn how to use the package.

4. General Purpose packages • What features make a package user-friendly? • Useful on-line help, on-line tutorials, spell checkers and grammar correction. • Clear menus for commands and icons. • Clearly defined shortcut commands. • HCI which can be set to users preferences. • What features can be used to change the HCI? • User defined menus and button bars. • Setting up of hotkeys for shortcuts, e.g. to print a file.

5. General Purpose packages • What are the advantages of MENU-DRIVEN PACKAGES? • Don’t have to remember commands. • Can’t make spelling mistakes that will stop commands working. • Features can be accessed very quickly, often at the touch of just one button. • What are the advantages of COMMAND-DRIVEN PACKAGES? • If commands are well known, it can be quicker than having to look through different menus to find a specific feature.

6. General Purpose packages What is DATA LINKAGE? Where data is shared in two (or more) different files. I.e. copied from an original file to a sharing file. What is DYNAMIC DATA LINKAGE? If the data in the original file is changed, data in the sharing file is also changed. E.g. publish and subscribe in Apple Works. What is STATIC DATA LINKAGE? Changing data in the original file does not change data in the sharing file. E.g. normal copy and paste in Apple Works.

7. General Purpose packages • What is covered by the DATA PROTECTION ACT? • Users must register any information held on computer about individuals. • Subjects must be allowed to see personal data held about them, and have it changed or erased if required. • All data should be correct, up to date and relevant. • Appropriate security measures should be taken. • Data should not be kept longer than is necessary. • What is the COMPUTER MISUSE ACT intended to stop? • Hacking and viruses.

8. General Purpose packages • What is a LAN? • Local Area Network. • Covers a small area, usually confined to a single building. • What are the advantages of a LAN? • Transfer data and programs between stations. • Expensive peripherals such as disc drives and printers can be shared. • E-mail service can be operated.

9. General Purpose packages • What is a WAN? • A Wide Area Network. • Can link computers spread over large geographical areas, e.g. in different countries. • Similar to LANs, although it would be largely pointless to share peripherals. • Slower transfer rates and more errors than a LAN.

10. Word Processing • What are the advantages of a word processor over pen and paper or manual typewriter? • Easy to fix errors without starting again. • Different fonts and styles can be used to improve the appearance. • Many copies can be produced quickly. • Features such as the spell checker can be used.

11. Word Processing • What limitations does a SPELL CHECKER have? • Does not correct grammatical errors, e.g. typing see when it should be sea. • Only gives options for words contained in its dictionary. The larger the dictionary, the better the spell checker. • Often produces errors with names that are correctly spelt. • Limitations can be overcome by having the spell checker learn certain words and names.

12. Word Processing How can the same word be found and changed to another wherever it occurs in a document? Search and Replace. This can be done in 2 ways: Selective: Finds each occurrence of the word one by one and asks if it should be changed. Global: Every occurrence of the word is changed automatically at once.

13. Word Processing • What are the advantages and disadvantages of global search and replace? • Changes can be made very quickly. • Mistakes can be very hard to fix and very destructive to a document. • Choosing to search for whole words only can stop mistakes like changing whether to wshether, when trying to change he to she. • What is a PRINTER DRIVER? • A piece of software which converts word processing codes for operations such as bold into printer codes, so that a document prints out exactly as it looks on the screen.

14. Word Processing What is WORD WRAP? When the end of a line of text is reached, the computer automatically puts any incomplete word onto the next line. What are STANDARD PARAGRAPHS? Pieces of text used to make letters by copying and pasting only the relevant pieces of text to a new document, to provide the required content.

15. Word Processing • What is a STANDARD LETTER? • Letters with basically the same content with spaces left to include personal details that can be individually typed in or filled by mail merge. • How is a MAIL MERGE performed? • Database is set-up containing all personal information contained in fields. • Letter is word processed, with spaces left for fields to be included. • Mail merge option produces the individualised letters.

16. Spreadsheets • How can the contents of a cell be protected? • Use cell lock which prevents a cell from being overwritten. • Useful for cells which contain important or complicated formulae. • How can the way in which a cell's contents are displayed be changed? • Change the cell attributes. • Useful to change a number to currency or change the way a date is displayed.

17. Spreadsheets • What function allows conditional values to be placed in a spreadsheet? • The IF function. • E.g. To display PASS or FAIL in cell A4 depending on whether cell A3 is above or below 50, then: • A4 = IF(A3 >50,"PASS","FAIL")

18. Spreadsheets What is RELATIVE REPLICATION? When a formula is copied from one cell to another, the value of the cell references change in relation to where the formula is copied to. E.g. A formula copied from one row to the row below, has the row number increased by one in cell values in the copied formula, e.g. 2's become 3's. i.e. A2 = B2 + C2 copied to A3 Becomes: A3 = B3 + C3

19. Spreadsheets E.g. 2. A formula copied from one column to the next, has the column letter changed by one in all cell values in the copied formula, e.g. A's become B's i.e. A5 = A3 + A4 copied to B5 Becomes: B5 = B3 + B4

20. Spreadsheets • What is ABSOLUTE REPLICATION? • When a formula is copied from one cell to another, with the same cell required in each of the formulae. • Usually only one part of a formula uses absolute replication, e.g. a cell containing a rate of VAT may be copied to a series of different cells. • Absolute replication is shown by putting dollar signs around the required cell, e.g. $C$3. • E.g. A3 = B3 + $C$3 copied to A4 • Becomes: A4 = B4 + $C$3

21. Databases • What is a database? • A structured collection of similar information to be sorted and searched through. • How is a database structured? • All the information is stored in a file. • Information on one particular item, say, a person, is called a record. • Each individual piece of information in a record is called a field. • e.g. A phone book is a database file. • One person’s details are a record. • Each person’s name, address and phone number are all fields.

22. Databases • What is a COMPUTED FIELD? • A field containing a calculation, based on one or more other fields. • How do you SORT on a field? • Choose Sort option. • Pick the field name to be sorted on from list of all fields. • Choose ascending (e.g. 1 to 10 or A to Z) or descending (e.g. 10 to 1 or Z to A). • Click on Sort. • How do you SEARCH on a field? • Choose Find option. • In required field, type what is to be found, e.g. in a car make field type Vauxhall. • Click on Find, and all Vauxhall cars will be displayed.

23. Databases • NOTE • At Credit level, sorting and searching will be done on two or more fields at the same time. The same procedures as above apply, where everything to be searched for should be entered before Find is chosen. • How do you estimate the storage requirements of a database? • Decide the maximum number of bytes for each field. • Add up each fields byte size to find the total byte size per record. • Multiply this total by the number of records in the file to get the total storage requirements.

24. Databases What is DATA VERIFICATION? Making sure that data is entered correctly - perhaps by entering the data twice and only accepting it if both entries match or have two people enter the data. What is DATA VALIDATION? Making sure that data entered is sensible and accurate, e.g range checks as shown below: Rejecting a date field with a day > 31 or < 0. Rejecting an age greater than 100 or less than 0. Rejecting a bill showing a total of £0 where goods have been ordered.

25. Databases • What is the purpose of an ID number in a database? • Uniquely identifies a record. • There may be 2 John Smith's in a database, but they can be individually identified as the ID Number will be different. • How can the contents of a database be kept private? • Create a password system that allows authorised users access to the database. • Creating different passwords can allow different users different levels of access. • E.g. A manager may have full access to the database (including financial information) with his password whilst a secretary may only be able to add new records and be restricted from viewing or changing certain information via their password.

26. Commercial Data Processing What is DATA VERIFICATION? Making sure that data is entered correctly - perhaps by entering the data twice and only accepting it if both entries match or have two people enter the data. What is DATA VALIDATION? Making sure that data entered is sensible and accurate, e.g. making a database field unique. A restricted choice in a database field.

27. Commercial Data Processing • What is the purpose of a CHECK DIGIT? • To make sure that data has been entered correctly, e.g. by bar code. • How does a check digit work? • Involves a calculation using previous digits in data which is performed by receiving computer. • If calculation result does not produce check digit then an error is highlighted, and the data has to be re-input. • Which input methods are likely to use a check digit? • Last digit of a bar code is likely to be a check digit.

28. Commercial Data Processing • What else is likely to be stored on a BAR CODE? • Stock number of item (not the same as the number in stock). • Manufacture’s name. • What is likely to be held on the main computer and NOT on the BAR CODE? • Price of item. • Stock level.

29. Commercial Data Processing • What are the advantages of using BAR CODES, MARK SENSE CARDS, Magnetic Ink Character Recognition (MICR) or Optical Character Recognition (OCR) for input? • Quicker to input. • Less likelihood of input error ( responsibility is taken away from human operator). • What further advantage does MICR have? • Can’t be forged or photocopied. • What disadvantages are there to OCR? • Poor handwriting may produce errors.

30. Commercial Data Processing • Why are customers given reference numbers in CDP systems? • To uniquely identify them - someone else may have exactly the same name but they can’t have the same reference number. • Provides a level of security if data is being entered online - e.g. ordering goods on the internet. • Why do other companies wish to buy lists of customers held by mail order companies? • To send them junk mail. • They know that these people have shown a willingness to use mail order.

31. Commercial Data Processing • What is BATCH PROCESSING? • Large amount of input is collected together over a period of time. • Is then processed together in one batch, where job is started and then needs no further interference from operator until job is complete. • Used with jobs that don’t need continual interaction from an operator, e.g. processing cheques and wages. • What advantages are there to batch processing? • All tasks are completed at the same time. • Job can usually be run overnight, not putting extra burden on the mainframe during the day.

32. Commercial Data Processing • What disadvantages are there to batch processing? • Jobs take time to do while awaiting sufficient input, e.g. cheques usually take 3 days to clear. • Stock levels can be misleading, as they will usually only show levels at the beginning of a day.

33. Commercial Data Processing • What is INTERACTIVE PROCESSING? • Where data is processed as the transaction is entered. • Decisions taken by the computer depend on user input, and are acted upon immediately. • Required where computer system must show situation as accurately as possible, e.g. when booking plane flights or withdrawing money from a bank machine. • What advantages are there to interactive processing? • Accurate stock levels are known - operators know exactly when more stock levels should be ordered. • Patterns can quickly be observed, such as busy times in a shop when more staff may be required.

34. Commercial Data Processing • How are interactive and batch processed jobs combined? • Interactive job is priority task and takes control of the CPU. • When there is a gap in this process, batch job is processed as a background task. • When priority task requires processor again, batch job is suspended until there is another gap. • Remember, there will be many gaps as the CPU can do many thousands (or millions) of tasks in one second.

35. Commercial Data Processing What do the following do in a CDP system? Systems Analyst Responsible for the design, development and upgrading of computer system. Computer Operator Responsible for the day to day running of the system - loading files, running programs etc. Computer Programmer Writes programs and buys programs used on the system, going on systems analysts specifications. Computer Engineer Responsible for fixing hardware problems and general maintenance of the computer systems.

36. Commercial Data Processing • How is loss of data covered in a CDP system? • Using Grandfather, Father, Son. • Son is current file and is used to update master file. • If corrupted, Father master file and transaction file are used to recreate Son file. • Father master file can be recreated in the same way using the Grandfather files. • At the end of the day, all files are updated with the Son becoming the Father and so on. • Old Grandfather file is discarded.

37. Commercial Data Processing • What advantages to CUSTOMERS are there of a company using a computerised CDP system? • They know for certain if goods are in stock and when they will receive them. • Less time is spent waiting in queues through features such as bar code readers. • What advantages to COMPANIES are there of a company using a computerised CDP system? • Less manual counting of stock, meaning staff can be employed for other purposes. • Increased customer satisfaction should improve sales. • Less mistakes made in things such as counting stock. • Easy to see which items are selling poorly and should perhaps be put on sale or discontinued.

38. Commercial Data Processing • What type of backing storage should be used in a CDP system and why? • Hard disc. • If a customer phones about an order they will want to quickly know what is happening with it. • As hard disc is a fast, random access device with masses of storage space for all customers this will do the job perfectly. • Would MAGNETIC TAPE ever be used? • Perhaps, but only as a back up which would hopefully never be needed, and would probably be stored off-site. • Tape would be used as a back-up because it is very cheap and has masses of storage space. • The drawback of tape is that it is a very slow, sequential access device.

39. Commercial Data Processing • How do companies prevent unauthorised access to files? • Assign passwords so that only certain users can access certain files. • Put a physical lock on room where data is entered, which can only be accessed by relevant staff. • What are remote terminals? • Terminals where data is input which are not in the same room (or even country) as the main computer which does the processing of data.

40. Commercial Data Processing • What does EFT (or EFTPOS) stand for? • Electronic Fund Transfer (at Point Of Sale). • How does EFT work? • Shop assistant passes customer’s debit card through a card reader. • Terminal checks that the card has not been marked as lost or stolen. • If total amount on bill is below a set limit the computer authorises the transaction. • If it is above this set limit, the terminal dials the bank’s computer to get automatic authorisation for the transaction.

41. Commercial Data Processing • What advantages are there to the company of EFTPOS? • Less money kept in shop, in case of robbery. • Transactions are processed quicker than cheques (typically one day instead of three). • What advantages are to the customer of EFTPOS? • Don’t need to carry so much money on them. • It is convenient if they want to make a spur of the moment purchase. • Itemised bills show exactly what has been bought and what prices have been charged, making it easier to track any mistakes.

42. Hardware • What is MAIN MEMORY? • Where programs and files are stored while the CPU processes them. • Physically made up of microchips. • Programs can be accessed immediately without being fetched from backing storage. • What is RAM? • Random Access Memory • Where programs and files are loaded from backing storage when used by the CPU. • Contents are erased when the computer is switched off.

43. Hardware • What is ROM? • Read Only Memory • Where programs and files are permanently stored. • Contents are placed on chip when made and cannot then be changed . • Every computer needs at least a little ROM, otherwise the computer would not be able to perform any task on startup. • What is BACKING STORAGE? • Where programs and files are stored permanently when not in use by the CPU. • Needed to store the contents of RAM, which would otherwise be lost.

44. Hardware • What happens when a floppy disc is FORMATTED? • Invisible circles and lines called tracks and sectors are laid on the disc’s surface. • A note of each sector and track number is stored on the disc. • When data is saved, it is accessed by referring to the track and sector numbers that it occupies. • Why can a hard disc hold more data than a floppy disc with the same dimensions? • Read/Write heads are smaller on a hard disc drive. • More tracks and sectors can therefore be crammed into the same space as on a floppy disc.

45. Hardware • What is a SEQUENTIAL ACCESS storage device? • Where data can only be read in the order that it is stored. • E.g. Tape. The tape has to rewind or fast forward until the required data is found. • It cannot go straight to the required data, slowing the process of fetching data down. • What is a RANDOM ACCESS storage device? • Where data be read in any order, and can be accessed immediately. • E.g. CD, floppy disc, hard disc. • This is a faster method of access.

46. Hardware • What factors should be used in comparing backing storage devices? • How fast data is accessed. • How much data is to be stored. • Cost of storage media. • Whether data has to be changed, added or deleted. • Portability of data, i.e. can it easily be taken from computer to computer? • What is MULTIMEDIA? • When a variety of specialised hardware are connected to the computer system at the same time. • Examples of specialised hardware are video players, CD's and speakers.

47. Hardware • What are SPECIALISED input and output devices? • Hardware adapted for a particular purpose. • E.g. to allow a disabled person to use a computer. • What practical purposes are specialised input and output devices used for? • Visually impaired people can use Braille keyboards for input and have speakers to allow voice output. • People who cannot use their hands use microphones to allow voice input to type documents. • Touch screens can allow people to input without the need for lots of typing.

48. Hardware • What is VIRTUAL REALITY? • Where the outside world is represented digitally, allowing the user to experience real-life situations through the use of computers and special hardware. • What hardware is required in virtual reality? • Special headsets and gloves linked to the computer. • What does LCD stand for? • Liquid Crystal Display • What are the advantages of an LCD screen? • A flat screen, taking up less space. • Low power usage.

49. Systems Software • What is a TRANSLATOR and why is it required? • A piece of software that translates high level or low level languages into machine code. • What is MACHINE CODE? • The computer’s own language, containing only 1’s and 0’s. • What is a HIGH LEVEL LANGUAGE? • Programming languages written in everyday language like English, with instructions telling the computer what to do, e.g. PRINT “Hello” in True Basic. • Errors can be quite easily found and fixed because the language looks like everyday language.

50. Systems Software • What is a LOW LEVEL LANGUAGE? • Programming language written in a language like machine code. • Much harder to understand than a high level language. • Easy to make mistakes and hard to find them to fix.