Cambridge IGCSE Computer Studies 0420 — 2009 May/June Paper 1 · Variant 1

This document consists of 20 printed pages. IB09 06_0420_01/5RP © UCLES 2009 [Turn over *0980685233* For Examiner’s Use UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education COMPUTER STUDIES 0420/01 Paper 1 May/June 2009 2 hours 30 minutes Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your Centre number, candidate number and name on all the work you hand in. Write in dark blue or black pen. You may use a soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. No marks will be awarded for using brand names of software packages or hardware. At the end of the examination, fasten all your work securely together. The number of marks is given in brackets [ ] at the end of each question or part question. www.XtremePapers.com

2 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 1 Explain, using examples where appropriate, the meaning of these computer terms. (a) batch processing [2] (b) data logging [2] (c) video-conferencing [2] (d) virtual reality [2] (e) virus [2]

3 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use 2 Name three devices used for automatic data capture. 1 2 3 [3] 3 (a) Give three features of a typical operating system. 1 2 3 [3] (b) Some microprocessor-controlled devices do not need an operating system. (i) Give one example of such a device. [1] (ii) Give one reason why it does not need an operating system. [1]

4 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 4 (a) What is an interrupt? [1] (b) How can an interrupt be generated? [1] (c) An exchange of signals between two devices to allow communication to take place. What is this computer function? [1] 5 (a) What is meant by the term CAD? [2] (b) Give two examples of the use of CAD. 1 2 [2]

5 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use 6 Today, electronic mail (email) is used as a means of communication. Describe three advantages and one disadvantage of using email. Advantage 1 Advantage 2 Advantage 3 Disadvantage [4]

6 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 7 Jon decides to buy a notebook (laptop) computer which he connects to the internet using a WiFi (wireless) broadband connection. Describe four security issues. 1 2 3 4 [4]

7 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use 8 An electronics company employs five people to answer technical queries over the telephone. The company has decided to develop a new system so customer queries are answered using a website rather than by telephone. (a) Describe two ways this change would affect the five employees. 1 2 [2] (b) Describe one advantage to the company of introducing this system. [1] (c) Describe two advantages to the customer of using this system. 1 2 [2]

8 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 9 A company produces animation effects using computers rather than producing them manually. (a) Describe three advantages of using computers to produce animation. 1 2 3 [3] (b) Each image takes about 400 kilobytes of storage. 25 images per second are produced. How much memory would be needed to store a 30-minute animation? [2]

9 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use 10 Expert systems help in medical diagnosis. Describe the steps taken to create and test expert systems. [4]

10 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 11 Scientific experiments are carried out where temperatures are taken at the start and at the end of each experiment. The volumes of gas being given off are also measured. The spreadsheet shows the measurements taken. A B C D E F 1 Experiment Number Start Temperature End Temperature Temperature Rise Gas Volume Gas Volume/ Temperature Rise 2 1 15 25 10 50 5.0 3 2 18 31 13 70 5.4 4 3 20 35 15 90 6.0 5 4 18 35 17 110 6.5 6 5 21 39 18 120 6.7 7 6 16 36 20 125 6.3 8 7 19 39 20 125 6.3 9 8 20 40 20 125 6.3 10 Mean Temperature Rise = 16.6 Maximum Ratio 6.7 (a) What formula is in D2 to find the Temperature Rise for Experiment Number 1? [1] (b) What formula is in D10 to find the Mean (average) Temperature Rise for all the experiments? [1] (c) What formula is in F10 to find the Maximum Ratio? [1] (d) How could the formula in D2 be used in D3 to D9 without writing it out another seven times? [2]

11 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use (e) The following graph was produced from the spreadsheet. 140 120 100 80 60 40 20 0 10 12 14 16 Temperature Rise Gas Volume 18 20 22 Which cells were highlighted to produce this graph? [2] (f) It was decided to link a computer to the apparatus so that all the results could be input directly and graphs produced automatically. Give two advantages of doing this. 1 2 [2]

12 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 12 (a) Robots are now used to do many jobs. Describe two jobs and give a reason why robots are used. Job 1 Reason 1 Job 2 Reason 2 [4] (b) Given the present technology, describe two jobs which robots cannot do. 1 2 [2]

13 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use 13 A company has decided to sell concert tickets on the internet rather than using agencies. Once the tickets are bought, the ticket confirmation and venue information are sent to the customer and the customer prints the tickets. (a) What two features would you expect to see on the company’s website? 1 2 [2] (b) How would the ticket information be sent to the customer? [1] (c) (i) How is it possible to ensure each ticket printed is unique? [1] (ii) How is it possible to prevent unauthorised tickets being used? [1]

14 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 14 Study the flowchart very carefully. START STOP T = 1 INPUT N X = 1 T = T * X X = X + 1 Is X = N + 1? OUTPUT T A B Yes No (a) Complete the table to show what outputs you would expect for the two inputs. Input N Output T 5 1 [2] (b) Write down a possible LOOP construct for the section A to B in the flowchart using pseudocode. [2]

15 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use 15 Aeroplanes use on-board computer power to allow them to operate more efficiently and safely. (a) How is data during a flight collected and fed back to on-board computers? [2] (b) Why are computer systems thought to be safer than human pilots? [2] (c) However, pilots are still used on all flights. Why is this? [2] (d) What recent developments have led to more use of computer control in newly designed aeroplanes? [1]

16 © UCLES 2009 0420/01/M/J/09 For Examiner's Use (e) Describe how the computer would know when to make course corrections during a flight. [2] (f) At the airport, baggage check-ins use bar codes which are read by computers. (i) What information would be stored on the bar code? [1] (ii) Why do airports use the bar codes on baggage? [1]

17 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use 16 The following flowchart shows what happens when a customer uses a credit card to pay for goods at a supermarket. Ten of the boxes are blank. Using the items from the list, insert the ten missing statements using the appropriate number only. Each statement may be used once only. START STOP STOP Insert credit card Type in PIN Yes Yes No Yes Yes No No No 1 are PIN details correct? 2 are there sufficient funds? 3 card removed 4 end transaction 5 is expiry date exceeded? 6 is card reported stolen? 7 money transfer takes place 8 print itemised bill 9 read credit card details 10 two computers communicate LIST OF STATEMENTS [5]

18 © UCLES 2009 0420/01/M/J/09 For Examiner's Use 17 A car sales company uses a database. Here are three tables from the database: New Car Sales Customer Reference Car Ordered Specification Delivery Date 151319 Cancelled order None Not applicable 162154 VW Golf 21215168 December 2008 171216 BMW 320i 07981624 February 2009 Customer Details Customer Reference Customer Name Customer Address Trade In? 141516 J Smith 7 Toll Road No 151319 M Kyle 14 Coast Road No 162154 D Khan 19 Main Street Yes 165196 S Gogic 555 Trabant Road No 171216 D Marques 21 Lakki Harbour Yes Car Manufacturer Specification Car Description List of Extras Cost Price ($) 07981624 BMW 320i C N O R V Z 48 500 21151198 VW Golf A B C E T U 16 200 21215168 VW Golf B D E F J L 21 000 31311115 Ford Focus A P R S W 17 000 (a) How many records are shown in the Customer Details table? [1] (b) (i) Which field connects the New Car Sales table with the Customer Details table? [1] (ii) Which field connects the New Car Sales table with the Car Manufacturer table? [1]

19 © UCLES 2009 0420/01/M/J/09 [Turn over For Examiner's Use (c) Give two reasons why List of Extras in the Car Manufacturer table is stored in code form. 1 2 [2] (d) A customer goes into the showroom and the salesperson keys in 162154. What fields and information would be shown on the output screen? [2] (e) Give one advantage to the car sales company of holding customer information on a database. [1]

20 Permission to reproduce items where third-party owned material protected by copyright is included has been sought and cleared where possible. Every reasonable effort has been made by the publisher (UCLES) to trace copyright holders, but if any items requiring clearance have unwittingly been included, the publisher will be pleased to make amends at the earliest possible opportunity. University of Cambridge International Examinations is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of University of Cambridge Local Examinations Syndicate (UCLES), which is itself a department of the University of Cambridge. 0420/01/M/J/09 For Examiner's Use 18 A small airport handles 400 flights per day from three airlines: FASTAIR (code FA) SWIFTJET (code SJ) KNIGHTAIR (code KA) Each flight is identified by the airline code and 3 digits. For example FA 156. Write an algorithm, using pseudocode or otherwise, which monitors the 400 flights into and out of the airport each day. The following inputs, processing and outputs are all part of the monitoring process: • input flight identification • calculate number of flights per day for each of the three airlines • output the percentage of the total flights per day by each airline • any validation checks must be included [5]

UNIVERSITY OF CAMBRIDGE INTERNATIONAL EXAMINATIONS International General Certificate of Secondary Education MARK SCHEME for the May/June 2009 question paper for the guidance of teachers 0420 COMPUTER STUDIES 0420/01 Paper 1, maximum raw mark 100 This mark scheme is published as an aid to teachers and candidates, to indicate the requirements of the examination. It shows the basis on which Examiners were instructed to award marks. It does not indicate the details of the discussions that took place at an Examiners’ meeting before marking began, which would have considered the acceptability of alternative answers. Mark schemes must be read in conjunction with the question papers and the report on the examination. • CIE will not enter into discussions or correspondence in connection with these mark schemes. CIE is publishing the mark schemes for the May/June 2009 question papers for most IGCSE, GCE Advanced Level and Advanced Subsidiary Level syllabuses and some Ordinary Level syllabuses. www.XtremePapers.com

Page 2 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 1 Generally, one mark per valid point. Two different types of example can gain two marks. (a) batch processing data collected together during time period processed all at once/in one go ref to JCL no need for human intervention done at night/off peak e.g. cheques, utility billing [2] (b) data logging automatic capture/sampling/gathering …. … and storing/recording of data/readings data from sensors devices contain ROM and RAM type memories e.g. weather conditions, temperature readings in an experiment [2] (c) video conferencing form of electronic comms using the Internet/WAN/ISDN link requires webcam/microphone/speakers image taken by webcam appears on window in participant’s monitor uses video compression software use of codec (analogue-digital translation) e.g. meetings that include delegates at different locations [2] (d) virtual reality computer simulation in a 3D world uses special interactive devices such as goggles, data gloves, suits,… makes user “feel as if they were actually there” operates in real time e.g. viewing houses, inside chemical plants, flight simulators, games [2] (e) virus program/software which copies itself/replicates created to corrupt/do damage to files/system/boot sector/data spread through email attachments/floppy disks/CDs/USB drives [2]

Page 3 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 2 Any three types of device from: bar code reader/scanner document scanner magnetic stripe reader smart card reader finger print reader retina scanner microphone digital (video) camera OCR OMR MICR RFID reader (radio frequency identification – used in electronic tagging) [3] 3 (a) Any three features from: file management/delete/copy/save/load files memory management I/O control error messages/handling interrupt handling user interface security issues logging on/off accounting/user account management time slicing multi access multi-tasking JCL/job control network management [3] (b) (i) any typical device such as a microwave oven [1] (ii) any one reason from: has only one set of tasks to perform simple input expected (e.g. keypad on front of device) simple, never-changing hardware would increase development and manufacturing costs [1] 4 (a) signal that temporarily stops execution of a program [1] (b) any one from e.g.: by a key stroke (e.g. BREAK key) by a printer (e.g. out of paper error) fault in program when running (e.g. try to divide by zero) end of an operation (e.g. end of time slice) [1] (c) handshaking [1]

Page 4 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 5 (a) any two points from: CAD is computer aided design allows engineers and architects to design/model/test new products uses special hardware such as hi res large screens, plotters, spaceballs makes use of features such as 2D, 3D, wire frames, costing, zoom references a library of spare parts links into CAM [2] (b) any two examples from design of e.g. : aerospace architecture vehicles consumer goods circuits ergonomics fashion kitchens/bathrooms lighting at concerts (chemical) plant/factories [2] 6 any three advantages and one disadvantage from e.g.: immediate (almost instantaneous) arrival of email in recipient’s inbox can send attachments easy to send out same message to several recipients can leave message in recipient’s mail box to be read later can pick up emails anywhere in the world can forward email without retyping it hacking is now a possibility/possibility of viruses (…but encryption minimises risk) lots of unnecessary messages (e.g. “I’m home!!!”) unsolicited mail some “dodgy” email material need computer equipment/Internet connection/email address attachments may be too large recipient may not be able to open an attachment recipient cannot receive original documents (NOT reference to costs or less paper used) [4] 7 any four from: hacking into his computer and change/read files viruses could be sent somebody “tapping into” his WiFi system credit card details being stolen bogus web sites stealing his computer (with security information on hard drive, for example) physical eavesdropping in a public place/shoulder surfing driving round looking for wi fi access/ WarDriving [4]

Page 5 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 8 (a) any two from: need to re-train de-skilling possible loss of jobs/redeployment loss of social interaction [2] (b) any one from: reduced costs to the company because of e.g. fewer staff/less office space can offer 24/7 customer services can advertise/offer new services and products automatically can recruit staff from anywhere standard responses to common queries [1] (c) any two from: 24/7 query system can see circuit diagrams etc. on screen can printout answers to take away/save and view again much faster response time (phone often busy, ….) less expensive (overseas phone calls to the company could be costly) don’t get conflicting advice/get correct response [2] 9 (a) any three from: can animate human movements to give more realism e.g. computer can “move” mouth properly to mimic speech use of avatars faster to produce the required number of frames …takes many artists a long time to do the drawings tweening speeds up the process editing/adjusting animations is easier/faster rendering to give more realism no need for any film/can store straight to CD/DVD [3] (b) There are various ways of completing this calculation, the following is one example: number of images needed = 30 x 25 x 60 = 45,000 memory needed = 45,000 x 400 x 1000 bytes = 18,000,000,000 bytes 18,000,000 Kbytes 18,000 Mbytes 18 Gbytes (1 mark for showing a correct method of working out plus 1 mark for correct answer including units) [2]

Page 6 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 10 any four point from: get information from experts input data into knowledge base populate rules base create inference engine create human-machine interface/question-answer sessions test system with “known” problems and solutions create output screens/format create/design validation routines [4] 11 (a) (D2) = C2 – B2 (D2) = (C2 – B2) [1] (b) (D10) = AVERAGE(D2:D9) (D10) = SUM(D2:D9)/8 (D10) = (D2+D3+D4+D5+D6+D7+D8+D9)/8 [1] (c) (F10) = MAX(F2:F9) [1] (d) select D2 and + appears drag down to D9 OR select D2 and select copy select D3 – D9 and select paste OR select/highlight D2 down to D9 select Auto/fill down [2] (e) (D1/D2 to D7/D8/D9) AND (E1/E2 to E7/E8/E9) Note: (D1/D2:E7/E8/E9) is worth 2 marks [2] (f) any two from: continuous (24/7) monitoring no need for human operators can run more experiments less chance of mistakes results/graphs will be produced without delay won’t miss any “unusual” data [2]

Page 7 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 12 (a) any two from e.g.: AND any two matching points from: assembling cars etc. } consistency of build/repeatability paint spraying } faster in operation than humans } can work without breaks/24-7 } health & safety bomb disposal } no danger to human life going into dangerous environments } equipped with sensors (can pick up data } automatically) vacuum cleaners/mowers } more leisure time for people [4] (b) any two from: any task requiring creativity (writing original prose, music, etc.) any task where logic/rules of programming can’t be applied one off task e.g. complex glass blowing [2] 13 (a) any two from: shopping basket checkout facility/form for customer details secure buying when using credit card “when customers booked X, they also booked Y” facility search facilities for artist drop down boxes to choose type of concert/ticket/prices calendar for dates (interactive) seating plan (interactive) map/directions help facilities currency conversions data/sales confirmation by email saved customer details/customised pages ability to listen to video clips of previous concerts recognise customer as soon as they log onto the site hyperlinks to other sites/navigation buttons bookmarking [2] (b) email + (attachment) text message printable page from web site [1] (c) (i) each barcode/reference number for the concert is different [1] (ii) any one from: link bar code/reference number to customer’s credit card send PIN/id with email to uniquely identify customer ask customer for proof of identity [1]

Page 8 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 14 (a) 120 1 [2] (b) for X = 1 to N + 1 OR repeat OR while X <> N + 1 do (T = T * X) (T = T * X) (T = T * X) X = X + 1 X = X + 1 next X until X = N + 1 endwhile (1 mark for correct first line of loop construct) (1 mark for correct loop control and last line of loop construct) [2] 15 (a) use of sensors use of ADC (if necessary) [2] (b) any two from: doesn’t get tired/works 24-7 less likely to make mistakes can respond to situations more quickly less chance of mis-understanding or mis-interpreting data [2] (c) any two from: in case computer program goes wrong/computer malfunction passenger confidence any “unusual” manoeuvres still best done in manual mode in case of emergencies [2] (d) any one from: faster processors greater component reliability considerable component (e.g. microchips) price reductions increased complexity of aeroplanes reduction in size of components reduction in power consumption [1] (e) any two from: flight plan keyed in satellite/global position read by computer (frequently) computer checks expected position based on time changes course if necessary….. …. by sending signals to the ailerons …. electric motors change aileron angles etc. operates in real time [2] (f) (i) any one from: passenger name/passenger ID destination(s)/point of departure flight id [1]

Page 9 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 (ii) any one from: tracking/uniquely identifies baggage/ensures baggage gets to right place increased security links to passenger/ensures luggage cannot travel without passenger [1] 16 [5] START STOP Insert credit card Type in PIN STOP No Yes Yes Yes No No No Yes 1 4 10 9 5/6 6/5 2 7 3 8 (1 mark) (1 mark) (1 mark) (1 mark) (1 mark)

Page 10 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 17 (a) 5 [1] (b) (i) Customer Reference (ii) Specification [2] (c) any two from: reduces typing errors uses less memory faster to type in quicker to sort store in one field easier to validate [2] (d) Car Description/Car Ordered VW Golf } Delivery Date Dec 2008 } New Car Sales Specification 21215168 } Customer Name D Khan } Customer Address 19 Main Street } Customer Details Trade In Yes } (1 mark 1 field name and contents from New Car Sales table plus 1 field name and contents from Customer Details table) List of Extras B D E F J L } Cost Price ($) 21 000 } Car Manufacturer (1 mark 1 field name and contents from Car Manufacturer table) [2] (e) any one advantage from: later use if customer wants to trade in again in 2 or 3 years’ time can send out new product information if safety/recall issues from car manufacturers service/safety check reminders [1] 18 marking points (1 mark per item up to the maximum of 5): initialise fa, sj and ka to zero correct loop inputs (in correct place) addition of number of flights per airline any validation checks carried out calculate percentages outputs (in correct place and ONLY if some evidence of any attempt at processing)

Page 11 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 sample program/algorithm fa = 0; sj = 0; ka =0; } 1 mark for x = 1 to 400 } 1 mark input lettercode } } 1 mark input numbercode } if lettercode = “FA” then fa = fa + 1 } } if lettercode = “SJ” then sj = sj + 1 } 1 mark } if lettercode = “KA” then ka = ka + 1 } else print “error” } 1 mark next x fapercent = fa/4 } } sjpercent = sj/4 } 1 mark } kapercent = ka/4 } print fapercent, sjpercent, kapercent } 1 mark [5]

Page 12 Mark Scheme: Teachers’ version Syllabus Paper IGCSE – May/June 2009 0420 01 © UCLES 2009 Sample flowchart: START Input lettercode Input numcode fa = fa+1 sj = sj+1 ka = ka+1 Is lettercode = FA Is lettercode = SJ Is lettercode = KA Output “error” Is x<=400 fapercent = fa/4 sjpercent = sj/4 kapercent = ka/4 x = x + 1 Ouput fapercent, sjpercent, kapercent Stop Yes Yes Yes No No No Yes No fa = sj = ka = 0 x = 1