Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level

Transcription

1 Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level * * COMPUTING 9691/11 Paper 1 May/June hour 30 minutes Candidates answer on the Question Paper. No additional materials are required. No calculators allowed. 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 an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, 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. This document consists of 14 printed pages and 2 blank pages. DC (RW/SG) /2 [Turn over

2 2 1 A programmer is developing an expert system. The expert system will diagnose problems in car engines. Describe four stages in the development of the expert system [4] 9691/11/M/J/16

3 3 2 Computer systems often use several types of storage. This storage is both primary and secondary. (a) State a use for each of the storage devices shown below. RAM... ROM... Hard disk drive... Optical storage device... [4] (b) Another type of storage device is a solid state drive (SSD). Give four advantages of using an SSD when compared with using a hard disk drive [4] 9691/11/M/J/16 [Turn over

4 3 Six statements and eight input devices are shown below. Draw a line to link each statement to the correct input device. 4 Statement Input device Device for reading text from a printed document and converting it into a form that can be used in a word processor Magnetic Ink Character Reader (MICR) Sensor Device that reads parallel lines of various widths and spacing Magnetic stripe reader Device that collects data values from the real world Optical Character Reader (OCR) Device that reads pencil or pen marks in pre-determined positions on a page Digital camera with video capture card Device that reads the data from a magnetised band on the back of a card or ticket Barcode reader or Barcode scanner Keyboard Device that acquires the images of an intruder entering a building Optical Mark Reader (OMR) [6] 9691/11/M/J/16

5 5 4 A teacher recruitment agency holds records of all its members on a database. The data for each teacher are entered into the database using a keyboard. Four of the fields are: teacher s unique 8-digit identification number (ID number) hourly rate in dollars (for example, 28.50) date of birth (DD/MM/YYYY) contact telephone number (for example, ) At the data entry stage, the data are validated. A presence check is one possible type of validation check. For each field, complete the following table to: State another possible validation check. Give an example of data value that would fail your chosen validation check. Each validation check and example must be different for each of the four fields. Field name Type of validation check Example of data which would fail the validation check IdNumber HourlyRate DateOfBirth PhoneNumber [8] 9691/11/M/J/16 [Turn over

6 5 (a) Three descriptions about data transmission are given below. For each description, tick ( ) the correct box to show: whether the data transmission is serial or parallel whether the transmission mode is simplex, half-duplex or full-duplex 6 (i) Data travel down a single wire one bit at a time in one direction only. Type of transmission serial Tick ( ) Mode of transmission simplex Tick ( ) parallel half-duplex full-duplex [2] (ii) Data can travel in both directions at the same time along a number of data channels/wires. Type of transmission serial Tick ( ) Mode of transmission simplex Tick ( ) parallel half-duplex full-duplex [2] (iii) One byte of data travelling in only one direction along eight data channels/wires. Type of transmission serial Tick ( ) Mode of transmission simplex Tick ( ) parallel half-duplex full-duplex [2] 9691/11/M/J/16

7 (b) Five communication terms are described below. In each case, name the term. 7 Communication method in which data are divided up into blocks; blocks travel to the destination by a variety of routes.... Communication that sends data along a single channel and uses the entire bandwidth of the medium.... Set of rules that govern the communication between computers on a network; for example, the type of parity to be used.... Communication method in which multiple analogue signals, each occupy a part of the bandwidth to carry data.... Communication method where a network uses the full bandwidth of a channel between two nodes before communication starts; only the two nodes can use the channel and they release it only when transmission ends.... [5] 9691/11/M/J/16 [Turn over

8 8 6 A company designs and sells computer games. John works in the marketing department. His manager asks him to produce a presentation to be shown in a large shopping mall to advertise the company s products. The presentation contains the following: graphs video with sound animation (a) Give one benefit and one drawback of using each one of these. Graphs Benefit... Drawback... Video with sound Benefit... Drawback... Animation Benefit... Drawback... [6] 9691/11/M/J/16

9 (b) Different departments in the company use the following software: desktop publishing spreadsheet graphics package word processor 9 For each type of software, describe one application relevant to the design and sales of the company s games. Desktop publishing... Spreadsheets... Graphics packages... Word processor... [4] 9691/11/M/J/16 [Turn over

10 10 7 (a) Complete the truth table for the following logic circuit. A B X C INPUT Workspace OUTPUT A B C X [4] 9691/11/M/J/16

11 (b) Draw a logic circuit which corresponds to the following logic statement. 11 X = ((NOT A AND B) OR (NOT B OR C)) OR (B AND C) A B X C [6] 9691/11/M/J/16 [Turn over

12 12 8 Two players, X and O, play a game. The players take turns to place either X or O in any one of the empty squares on the board. The board shows a current game in play X O 2 X 3 O 4 5 O 6 X O O X 7 O X X X O Either player (X or O) wins when there are four X s or four O s next to each other: in a row, or in a column, or in a diagonal line A programmer is writing a computer program for the game. The programmer stores the mark X as the value 1 and the mark O as the value 2. The programmer uses a 2-dimensional array, Board[1 : 7, 1 : 7], to store the current value in each square. (a) State what value the programmer could use to represent an empty square. [1] (b) Describe how the programmer could initialise the array Board for the start of the game. [2] (c) For the game shown above, show the values that are currently stored in the following array elements. State whether the first index number is used for the row or column. Board[6, 4]... Board[7, 5]... [2] 9691/11/M/J/16

13 13 (d) It is possible to play the game against the computer. Player O is the computer and player X is a human. Player X selects where to place their X in the game. Player X plays the game on a standard personal computer with a keyboard, mouse and monitor. Describe two different ways in which player X could select the square for each of their moves [2] (e) Explain how the computer program would determine, after each turn, if a player has won the game. [3] 9691/11/M/J/16 [Turn over

14 14 9 A customer wishes to buy a new car. The customer visits a car factory which has a sales area. The customer specifies various features for their car using a computer system. The car features to choose include model, body colour, seat material and engine size. The factory accepts the customer s specification and provides them with their chosen car within an hour. (a) Name a suitable hardware device to capture the customer s choices. Describe the interface that allows the customer to specify the features of their car. [4] (b) The factory stores cars in a 30-level warehouse that has separate storage areas, known as pods. A computer-controlled forklift system removes a car from its pod. Each pod has a unique identification; for example, A17 refers to pod A on level 17. A database stores data for all the cars that are stored in the pods. Explain how the customer s car specification is matched to a car in one of the pods and how the car is then withdrawn from the pod. [4] 9691/11/M/J/16

15 15 BLANK PAGE 9691/11/M/J/16

16 16 BLANK PAGE 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. 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. 9691/11/M/J/16

17 Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level * * COMPUTING 9691/12 Paper 1 May/June hour 30 minutes Candidates answer on the Question Paper. No additional materials are required. No calculators allowed. 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 an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, 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. This document consists of 15 printed pages and 1 blank page. DC (CW/FD) /4 [Turn over

18 2 1 A company develops learning materials. These are computer-based and consist of a number of interactive presentations. The materials are supplied on a CD-ROM. (a) Name the type of secondary storage medium being used....[1] (b) Explain the term interactive in this context....[2] (c) Give one reason why the company sells the learning materials on a CD-ROM....[1] (d) Software on the CD-ROM can record a user s progress in working through the material. The user can stop the presentation at any point and then resume where they left off at a later time. A student buys the learning materials. (i) State why the materials cannot be used directly from the CD-ROM....[1] (ii) State what the student must do before they can use the presentations effectively....[1] (e) One of the presentations is on the topic of verification and validation. Explain the differences between verification and validation. Include examples in your explanation....[3] 9691/12/M/J/16

19 3 Question 2 begins on page /12/M/J/16 [Turn over

20 2 (a) A processor controls a heating system. To do this, it uses: 4 a temperature sensor a device in which a small electrical input current switches a much larger current for the heater The following steps, when put into the correct sequence, describe how to switch on the heater. Put the steps into the correct sequence using the numbers 1 to 5. Step Sequence number Sensor reading is sent to the microprocessor Microprocessor checks sensor reading against stored temperature value Temperature reading is taken by the analogue sensor If the sensor reading is less than the stored value, the microprocessor sends a signal to switch on the heater Sensor reading is converted into a digital value using an ADC [4] (b) Name a suitable sensor for each of the following applications. State what the sensor detects in each case. (i) Intruder detection system Sensor... Reason for choice......[2] (ii) Switching on a street lamp when it gets dark. Sensor... Reason for choice......[2] 9691/12/M/J/16

21 5 (iii) Counting people entering a building. Sensor... Reason for choice......[2] 9691/12/M/J/16 [Turn over

22 3 A small business has several computers, each with a single-user operating system. (a) State what is meant by single-user. 6...[1] (b) The business uses an Internet Service Provider (ISP) to provide a high-speed Internet connection. (i) State what high-speed means in this context....[1] (ii) Give two applications for which a high-speed broadband connection is essential [2] (c) Give two benefits of using a broadband connection, other than high speed [2] 9691/12/M/J/16

23 (d) The ISP advertises a download speed of 80 Mbits/second. 7 (i) State the number of Mbytes/second this is equivalent to....[1] (ii) Calculate the time taken to download an 80 Mbyte file....[1] The business complains to the ISP that the actual download speed is only 0.8 Mbits/second. (iii) Calculate the time taken to download the same 80 Mbyte file....[1] (iv) Suggest one reason why the download speed is lower than advertised....[1] 9691/12/M/J/16 [Turn over

24 4 (a) The system life cycle consists of several stages. 8 Complete the numbered list below by placing the following stages in their correct place: Design of the system Maintenance of the system Identification of the problem Analysis of the problem Installation of the system 1 2 Feasibility study 3 Information collection / fact finding Development and testing 7 8 [4] (b) Describe each of the following stages in the system life cycle. (i) Fact finding...[3] 9691/12/M/J/16

25 9 (ii) Maintenance of the system...[4] (c) (i) Identify the information shown in a Data Flow Diagram (DFD)....[2] (ii) State the stage in the system life cycle in which a DFD would be used....[1] 9691/12/M/J/16 [Turn over

26 10 5 (a) Complete the truth table for the following logic circuit. A B X C INPUT Workspace OUTPUT A B C X [4] 9691/12/M/J/16

27 (b) Write a logic statement which represents the following logic circuit. A 11 X B C...[3] (c) For each circuit below, state the equivalent single logic gate. Circuit 1 Circuit 2 A X A B X B Circuit 1... Circuit 2...[2] 9691/12/M/J/16 [Turn over

28 12 6 An airport car park is made up of 5 rows, each with 8 bays. When a car enters the car park, a computer system captures its registration plate (number plate) data. The computer system is able to determine the row and bay in which the car is parked. (a) Outline a suitable method for capturing the registration data of each car....[2] (b) When a customer wants to leave the car park with their car, they enter their registration plate data at a ticket machine. The machine calculates and displays the parking fee and the location of the car (for example row 5, bay 4). (i) Name a suitable device to enter the car registration and display the location of the car....[1] (ii) Describe how the computer system can calculate the parking fee....[2] The layout of the car park is shown. There are currently seven parked cars. row 1 row 2 row 3 row 4 row 5 bay 1 bay 2 bay 3 bay 4 bay 5 bay 6 bay 7 bay 8 The computer system stores the registration plate data of each parked car in a 2-dimensional array, ParkingArea. 9691/12/M/J/16

29 13 (c) (i) Explain how the computer system initialises the ParkingArea array....[2] (ii) Using the given diagram, state whether or not there is currently a car registration stored in ParkingArea[4, 3]....[1] (iii) When the driver parked the car, the computer system stored the registration plate data in the appropriate element of the ParkingArea array. When paying the parking fee, the driver enters the registration plate data at the car park ticket machine. Describe how the computer system uses the ParkingArea array to find the location of the car....[3] (d) The car park has ten levels. Suggest how a programmer could modify the ParkingArea array to store the data for all ten levels....[2] 9691/12/M/J/16 [Turn over

30 7 A student wrote the following five statements on a computing exam paper. Explain why each statement is incorrect. 14 (i) Backing up data on a pen drive always allows a user to recover data in the event of data loss caused by a virus....[2] (ii) A stack data structure operates on the first-in, first-out principle and is controlled by two pointers....[2] (iii) The two bytes and both have even parity since their denary values, 76 and 110, are even....[2] (iv) Broadband is a method of communication which is digital in nature; it uses a single channel that uses the entire bandwidth of the medium....[2] 9691/12/M/J/16

31 15 (v) Buffers use ROM memory....[2] 9691/12/M/J/16

32 16 BLANK PAGE 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. 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. 9691/12/M/J/16

33 Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level * * COMPUTING 9691/13 Paper 1 May/June hour 30 minutes Candidates answer on the Question Paper. No additional materials are required. No calculators allowed. 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 an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, 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. This document consists of 14 printed pages and 2 blank pages. DC (NH/JG) /3 [Turn over

34 1 State two differences between RAM and ROM [2] 2 (a) The diagram below shows the terms baseband and broadband. Five features about these terms are also shown. Draw one or more lines from each term to its correct feature(s). Feature Allows multiple transmissions at the same time Baseband Each transmission uses a portion of the available bandwidth Each transmission uses all of the available bandwidth Broadband Transmission uses the entire bandwidth of the medium during the transmission When connecting to the Internet, upload speeds and download speeds are usually different [5] 9691/13/M/J/16

35 3 (b) (i) State two advantages of using broadband rather than using a dial-up connection when accessing the Internet [2] (ii) Give two applications where it is essential to have a high-speed broadband connection [2] (c) Computers can send data across networks using packet or circuit switching. (i) Explain the meaning of the term circuit switching....[2] (ii) When using packet switching each packet has a header. The header includes the destination address. Name three other data items found in the header [3] 9691/13/M/J/16 [Turn over

36 3 Six descriptions and nine computing terms are shown below. Draw a line to link each description to the appropriate computing term. 4 Description Computing term Generate a value from a string of text using a mathematical function Archiving Copy files for long term storage; the files are no longer in active use and a computer often stores them in compressed form Back up Buffer A computer often reads a file of records from the beginning, in sequence, until a required record is found Disk formatting Disk operating system Prepare storage media (such as hard disk) for initial use File compression Hashing Physical memory that temporarily stores data waiting for transfer Interrupt A signal that hardware or software sends to the processor requesting immediate attention Serial access [6] 9691/13/M/J/16

37 4 (a) Complete the truth table for the following logic circuit. A 5 B X C INPUT Workspace OUTPUT A B C X [4] (b) Write a logic statement for the logic circuit in part (a)....[3] 9691/13/M/J/16 [Turn over

38 6 5 A teacher uses spreadsheet software to analyse the test results of her students. A section of the spreadsheet is shown below: A B C D E F 1 student name maths (%) computing (%) geography (%) average percentage (all subjects) distinction, pass or fail 2 Tomas Sean Toni Irina Arslan Ciprian (a) The teacher will write the formula MAX(B2:B7) into cell B10. Describe what the value calculated in B10 will represent....[2] (b) Students are to be awarded an overall grade based on their average percentage (in column E). The grades are calculated in column F. Grades are awarded as follows: 70% or more is a Distinction 50% to 69% is a Pass less than 50% is a Fail Explain how the teacher can calculate these grades....[2] 9691/13/M/J/16

39 7 (c) There are other features of spreadsheet software that the teacher could use in her analysis of the students performance. Name and describe two of these [4] (d) Spreadsheet software is an example of off-the-shelf software. Give two advantages of off-the-shelf software compared to custom-written software [2] 9691/13/M/J/16 [Turn over

40 6 (a) A bus network is one type of network topology. 8 Name two other network topologies. Give one benefit and one drawback of each topology compared to a bus network Benefit... Drawback Benefit... Drawback... [6] 9691/13/M/J/16

41 9 (b) Local Area Networks (LANs) and Wide Area Networks (WANs) need specialist hardware to operate correctly. Name three hardware items that either network needs. Describe their function in each case Function Function Function... [6] 9691/13/M/J/16 [Turn over

42 10 7 A parcel delivery company collects and delivers parcels. Customers telephone to arrange for collection of a parcel. Delivery is then scheduled for the next day. The telephone operator, delivery drivers and manager all work in the same building. The company uses a very old computer system to process collections and deliveries. This system is unable to deal with the increasing number of customers. A systems analyst has been employed to investigate the modernisation of this current computer system. (a) One part of the investigation is fact finding. Explain how the systems analyst can use the following fact finding methods to investigate this collection and delivery service. Observation Examine documentation Interviews Questionnaires [8] 9691/13/M/J/16

43 (b) The existing user interface uses a form. The telephone operator keys in all the data. 11 ROCKICT Parcel System Type in the collection point Type in the destination Type in the pick-up date Type in earliest pick-up time Type in latest pick-up time Express delivery? Insurance? >... >... >... /... /... >... :... >... :... >... >... Press <ENTER> to go to the next screen (i) Explain why this existing interface is not efficient....[2] (ii) Describe three ways to improve the existing user interface [3] 9691/13/M/J/16 [Turn over

44 12 8 A process is devised for encoding letters using 20 bits. The process starts by giving each letter of the alphabet a value: A = 1, B = 2, C = 3,..., Z = 26. The value for each letter is represented using 16 bits. For example, the letter V (22 nd letter) is represented by: A further 4 bits store an encoding key. This key is the number of places by which the encoding process moves the 16-bit pattern to the left. For example, the encoding key: means that the encoding process moves each bit in the 16-bit pattern 7 places to the left. The 16-bit pattern then becomes: The 4-bit pattern and the 16-bit pattern together form the encoded letter V : (a) Y is the 25 th letter of the alphabet. (i) Show how 16 bits initially store the value for this letter: [1] (ii) The encoding process uses the following 4-bit encoding key: Show how the letter Y is now transformed: [1] 9691/13/M/J/16

45 13 (b) Find the letter of the alphabet that has been encoded here. Show your working [2] (c) The encoding process uses the following 4-bit encoding k ey: Describe the problem that this encoding key will cause....[2] 9691/13/M/J/16 [Turn over

46 9 A student wrote the following five answers on a computing exam paper. Give a reason why each answer is incorrect. 14 (a) The binary number has odd parity since the number ends in a 1 and is therefore not an even number....[1] (b) In a computer-controlled heating system, sensors send signals to the heaters to switch on or off....[1] (c) The user guide supplied with software contains a program listing and a systems flowchart....[1] (d) Data structures known as stacks use FIFO to insert and remove data....[1] (e) A command line interface (CLI) uses icons to represent applications that are launched by a click of the mouse button....[1] 9691/13/M/J/16

47 15 BLANK PAGE 9691/13/M/J/16

48 16 BLANK PAGE 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. 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. 9691/13/M/J/16

49 Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level * * COMPUTING 9691/21 Paper 2 May/June hours 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 an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. 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. This document consists of 14 printed pages and 2 blank pages. DC (NF/SG) /3 [Turn over

50 1 Zara wants to write a program to print a set of name labels for a group of students. 2 Each label will show the name surrounded by a border. There is one gap line above and below the name line. This gap line only has the border symbol at the start and end. There are two spaces between the border symbol and the name. Here is a @@@@@@@@@@ The user will choose the border symbol for the set of labels. Zara writes pseudocode for her program: INPUT Symbol REPEAT INPUT Name LabelWidth LENGTH(Name) + 6 CALL PrintTop2Lines(Symbol, LabelWidth) CALL PrintNameLine(Symbol, Name) CALL PrintBottom2Lines(Symbol, LabelWidth) UNTIL Name = "NoName" (a) Write program code for the procedure PrintNameLine(Symbol, Name) Programming language... Code [4] 9691/21/M/J/16

51 3 Zara uses top-down design and refines her solution: PROCEDURE PrintTop2Lines(Symbol : CHAR, LabelWidth : INTEGER) CALL PrintGapLine(Symbol, LabelWidth) CALL PrintSymbolLine(Symbol, LabelWidth) ENDPROCEDURE PROCEDURE PrintBottom2Lines(Symbol : CHAR, LabelWidth : INTEGER) CALL PrintSymbolLine(Symbol, LabelWidth) CALL PrintGapLine(Symbol, LabelWidth) ENDPROCEDURE (b) Write program code for the procedures below. Programming language... PrintSymbolLine(Symbol : CHAR, LabelWidth : INTEGER) PrintGapLine(Symbol : CHAR, LabelWidth : INTEGER)... [6] 9691/21/M/J/16 [Turn over

52 4 (c) Zara now decides that the name labels should all be of the same width, regardless of the length of the name. She amends her top-level design: CONSTANT LabelWidth = 20 INPUT Symbol REPEAT INPUT Name CALL PrintTop2Lines(Symbol, LabelWidth) CALL PrintNameLine(Symbol, Name, LabelWidth) CALL PrintBottom2Lines(Symbol, LabelWidth) UNTIL Name = "NoName" The name is to be centred within the label. (i) Rewrite the procedure PrintNameLine. Your solution should allow for the case when the name has an odd number of characters. Programming language... Code [7] 9691/21/M/J/16

53 5 (ii) Describe what happens when a name consists of 18 or more characters.... [2] (iii) Suggest a solution to the problem that you described in part (c)(ii).... [2] (d) Zara used top-down design to develop her modular solution. Give two benefits of a modular solution [2] (e) The pseudocode Zara wrote in part (c) has some features that make it easier to read and understand. State three such features [3] 9691/21/M/J/16 [Turn over

54 6 2 A city has a metro line with five stations. The transport department wa nts to introduce a ticket price calculator for its website. The transport department gives the following specification to a programmer. Tickets cost 25 cents for each kilometre (km) travelled. The user chooses the origin and destination of their journey from a list: Station number Station name 1 Airport 2 Industrial Centre 3 City Centre 4 University 5 Sports Stadium Journeys can start and end at any of the following stations. Travel can be in either direction. The distances between adjacent stations are: Between stations Distance (km) 1 and and and and 5 3 To use the ticket price calculator, a user clicks on the Ticket Price Calculator button. This calls the procedure TicketCalculator. The user inputs the numbers of their chosen start and end stations. The procedure calculates and displays the ticket price. 9691/21/M/J/16

55 7 (a) Write program code to declare and initialise a one-dimensional array Interval to store the four distances between the stations. Programming Language... Code [2] (b) Carefully choose four sets of test data to test the procedure TicketCalculator. Explain the reason for your choice of test data. Your reason for each test should be different. Only choose journeys where: station numbers are valid origin and destination station numbers are different One set of test data has been done for you. Test number Station number Origin Destination Reason for choice Tests longest journey, starting at first station, finishing at last station [4] 9691/21/M/J/16 [Turn over

56 8 (c) Use the flowchart opposite to write program code for the procedure TicketCalculator. Programming language... Code.... [10] 9691/21/M/J/16

57 9 PROCEDURE TicketCalculator INPUT Origin INPUT Destination Initialise Distance Is Origin > Destination? Yes Swap Origin and Destination No i Origin Loop Distance Distance + Interval[i] Increment i Is i = Destination - 1? No Yes TicketPrice Distance * 0.25 OUTPUT TicketPrice ENDPROCEDURE 9691/21/M/J/16 [Turn over

58 10 3 Alessio has been asked to write a computerised table booking system for a restaurant. The restaurant has 12 tables, each seating between 2 and 8 people. The restaurant manager wants the following facilities: take a new booking cancel a booking report on which table(s) are available As a first attempt, Alessio designs his program to take bookings for one evening only. Each table is only booked once per evening. He writes the pseudocode for his main program: CALL Initialisation EndProgram FALSE REPEAT CALL DisplayOptions INPUT Option CASE OF Option 1: CALL TakeBooking 2: CALL CancelBooking 3: CALL AvailableTablesReport 4: EndProgram TRUE OTHERWISE OUTPUT "Error invalid input" ENDCASE UNTIL EndProgram = TRUE Each booking is for a number of customers (size of the group). Each table has a number of seats. The procedure Initialisation will set up arrays TableSeats, Booked and GroupSize as follows: TableNumber TableSeats Booked GroupSize FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE /21/M/J/16

59 11 (a) When a booking enquiry is made, the number of customers is given. Complete the pseudocode for the procedure TakeBooking: PROCEDURE TakeBooking DECLARE, : INTEGER DECLARE : BOOLEAN INPUT NumberOfCustomers // initialise search for a suitable table Found FALSE TableNumber = REPEAT // find a table with enough seats TableNumber TableNumber + 1 IF TableSeats[ ] AND Booked[ ] THEN Found TRUE ENDIF UNTIL OR IF Found = FALSE THEN // no tables left with enough seats ELSE // make the booking Booked[ ] GroupSize[ ] OUTPUT "Table number booked: ", TableNumber ENDIF ENDPROCEDURE [11] 9691/21/M/J/16 [Turn over

60 12 (b) To cancel a booking, the table number is quoted. Complete the pseudocode for the procedure CancelBooking. PROCEDURE CancelBooking INPUT TableNumber IF THEN OUTPUT "Error this table is not booked" ELSE // cancel booking Booked[ ] GroupSize[ ] OUTPUT "Booking cancelled" ENDIF ENDPROCEDURE [4] (c) The restaurant manager wants a report to show all available tables, each with its number of seats. Write pseudocode for the procedure AvailableTablesReport.... [4] 9691/21/M/J/16

61 13 (d) The manager wants to store the name and telephone number of the customer making the booking. At the time the booking is made, the manager also wants to collect a deposit ($5 per person). The program will record the deposit paid. Alessio decides that a record structure would be more suitable for his program. (i) Write program code to define a booking record with identifier BookingType and the fields TableSeats, Booked, GroupSize, CustomerName, CustomerTelNumber, AmountDepositPaid. Programming language... Code [5] (ii) Each restaurant table will have its data stored in its own booking record. Alessio decides to use an array of records. Write program code to declare the array TableBookings for the 12 table records. Use the record structure you defined in part (d)(i). Programming language... Code [3] 9691/21/M/J/16 [Turn over

62 14 (e) At the end of the day, the computer is shut down. Before the program stops, the array data from TableBookings must be saved to a new sequential file TableBookings.DAT Write program code for the procedure SaveToFile. Programming language... Code [6] 9691/21/M/J/16

63 15 BLANK PAGE 9691/21/M/J/16

64 16 BLANK PAGE 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. 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. 9691/21/M/J/16

65 Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level * * COMPUTING 9691/22 Paper 2 May/June hours 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 an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. 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. This document consists of 15 printed pages and 1 blank page. DC (CW/FD) /3 [Turn over

66 2 1 A high-level programming language has built-in string handling functions specified as follows: ONECHAR(ThisString : STRING, x : INTEGER) RETURNS STRING returns a string value consisting of one character from the string ThisString at position x. For example: ONECHAR("STOP", 4) returns "P" CONCAT(String1 : STRING, String2 : STRING) RETURNS STRING returns a string value consisting of String1 followed by String2. For example: CONCAT("HE", "LLO") returns "HELLO" Use the pseudocode on the following page to complete the trace table for the function call Process("011101", "001100") String1 String2 Position Digit1 Digit2 Sum Carry Result "011101" "001100" "0" "" [6] 9691/22/M/J/16

67 3 FUNCTION Process(String1, String2 : STRING) RETURNS STRING Carry "0" Result "" FOR Position 6 DOWN TO 1 Digit1 ONECHAR(String1, Position) Digit2 ONECHAR(String2, Position) IF Carry = "0" THEN CASE OF Digit1 "0": Sum Digit2 "1": CASE OF Digit2 "0": Sum "1" "1": Sum "0" Carry "1" ENDCASE ENDCASE ELSE CASE OF Digit1 "0": CASE OF Digit2 "0": Sum "1" Carry "0" "1": Sum "0" ENDCASE "1": CASE OF Digit2 "0": Sum "0" "1": Sum "1" ENDCASE ENDCASE ENDIF Result CONCAT(Sum, Result) ENDFOR RETURN Result ENDFUNCTION 9691/22/M/J/16 [Turn over

68 4 2 Ryan wrote the following recursive function using pseudocode. 01 FUNCTION Power(Number : INTEGER, Exponent : INTEGER) RETURNS INTEGER 02 IF Exponent = 0 03 THEN 04 Result 1 05 ELSE 06 Result Number * Power(Number, Exponent - 1) 07 ENDIF 08 RETURN Result 09 ENDFUNCTION (a) (i) How can you recognise that this function is recursive?... [1] (ii) A recursive solution to a problem always has a base case (the stopping condition) and a general case. Give the line number of the statement that is executed in the base case. Give the line number of the statement that is executed in the general case.... [2] (b) (i) State the value returned by Power(3, 0).... [1] (ii) State the value returned by Power(3, 1).... [1] (c) (i) Explain what happens when the call is Power(3, -1).... [2] 9691/22/M/J/16

69 5 (ii) Describe the changes that will need to be made to function Power to address the problem that you described in part (c)(i).... [2] (d) An alternative method for the Power function is to use an iterative solution. Using pseudocode, write Power as an iterative function. FUNCTION Power(Number : INTEGER, Exponent : INTEGER) RETURNS INTEGER... [4] (e) A problem may have both an iterative solution and a recursive solution. Each has its own benefits. State one benefit of each solution. Iterative... Recursive [2] 9691/22/M/J/16 [Turn over

70 6 (f) Ryan uses his recursive function Power in a program. He will use debugging tools to check the Power function works as expected. The debugging tools include breakpoints, variable watches and stepping. (i) Identify where it is appropriate to set a breakpoint. Justify your answer.... [2] (ii) Ryan wants to set up a variable watch window for his function. 01 FUNCTION Power(Number : INTEGER, Exponent : INTEGER) RETURNS INTEGER 02 IF Exponent = 0 03 THEN 04 Result 1 05 ELSE 06 Result Number * Power(Number, Exponent - 1) 07 ENDIF 08 RETURN Result 09 ENDFUNCTION State the variable(s) that would be appropriate to list in the variable watch window. Justify your choice.... [2] (iii) Explain how Ryan uses these debugging tools to check the execution of his recursive function.... [3] 9691/22/M/J/16

71 7 Question 3 begins on page /22/M/J/16 [Turn over

72 8 3 A crossword puzzle is based on a grid made up of white and black squares. The white squares are to be filled with letters to form words across the grid and down the grid. The crossword puzzle designer provides clues for each word. Words consist of at least 2 letters. The square where a word starts, across or down, is numbered. The numbering starts at the top left of the grid and is consecutive, row by row. Here is an example of a crossword grid: (a) Zara is given a grid design of white and black squares. This design does not yet contain numbers. Zara wants to write a program to set up a data structure for the grid data. The data for each square will represent either: a white square a black square a white square with a number (i) A white square with a number is represented by the integer value of the number. Suggest a suitable value to represent: A white square... A black square... [2] (ii) Write program code to declare the data structure with identifier Puzzle for a grid design of size squares. Programming language [3] 9691/22/M/J/16

73 9 (iii) Initially, all squares are to be white squares. Write program code to initialise Puzzle. Programming language... Code [3] (iv) The seventh square in the first row of the example crossword grid is black. Write program code for the assignment statement to set the corresponding element of Puzzle to represent black. Programming language [2] Where there are other black squares in the design, Zara writes additional assignment statements. (b) The next stage for Zara is to design a procedure that numbers the relevant white squares. A word begins in a square if the square is: a white square, and the first of a sequence of at least 2 white squares across or down Zara starts to write the pseudocode for the procedure CheckForStartOfWord. This will check whether a square at ThisRow and ThisColumn is the start of a word. (i) Complete the pseudocode for the global declarations. CONSTANT WHITE =...// value from part(a)(i) CONSTANT BLACK =...// value from part(a)(i) [2] 9691/22/M/J/16 [Turn over

74 10 (ii) Complete the pseudocode: PROCEDURE CheckForStartOfWord(Puzzle, ThisRow, ThisColumn, Across, Down) Across FALSE // will change to TRUE // if a word across starts in this square Down IF Puzzle[ThisRow, ThisColumn] =... ENDIF THEN // this square is white // check for sequence across IF ThisColumn < 11 // check not in last column ENDIF THEN // check this is the first column or a black square to the left IF (ThisColumn = 1 OR Puzzle[ThisRow, ThisColumn - 1] = BLACK) // check that the square to the right is white AND (Puzzle[...] = WHITE) THEN Across TRUE... // check for sequence down IF ThisRow < 11 // check not in last row ENDIF THEN // check this is the first row or a black square above IF (ThisRow =... OR Puzzle[... ] = BLACK) // check that the square below is white AND (...) THEN ENDIF Down... ENDPROCEDURE [8] 9691/22/M/J/16

75 11 (iii) The procedure CheckForStartOfWord(Puzzle, ThisRow, ThisColumn, Across, Down) has five parameters. Parameters can be passed by reference or by value. For each parameter, tick ( ) to show how it should be passed. Parameter By reference By value Puzzle ThisRow ThisColumn Across Down [3] (c) Zara wants her program to number the squares where a word starts. She also wants the program to create two lists, AcrossList and DownList. AcrossList will contain the numbers of the starting squares of words going across. DownList will contain the numbers of the starting squares of words going down. Note that a square can be a starting square for a word going across and a word going down. The same number would therefore be contained in both lists. For example, the given puzzle has these lists. Squares numbered 5, 12 and 17 are starting squares for words going across and words going down AcrossList DownList /22/M/J/16 [Turn over

76 12 Z ara designs this part of the program by writing pseudocode. Convert this pseudocode into program code. NextNumber 1 // first number for numbering starting squares a 1 // pointer to first element of AcrossList d 1 // pointer to first element of DownList FOR ThisRow 1 TO 11 FOR ThisColumn 1 TO 11 CALL CheckForStartOfWord(Puzzle, ThisRow, ThisColumn, Across, Down) IF Across = TRUE THEN AcrossList[a] NextNumber // update AcrossList a a + 1 ENDIF IF Down = TRUE THEN DownList[d] NextNumber // update DownList d d + 1 ENDIF IF Across = True OR Down = TRUE THEN Puzzle[ThisRow, ThisColumn] NextNumber // number the square NextNumber NextNumber + 1 ENDIF ENDFOR ENDFOR 9691/22/M/J/16

77 13 Programming language... Code [8] 9691/22/M/J/16 [Turn over

78 14 (d) The pseudocode Zara wrote in part (b) and part (c) has some features that make it easier to read and understand. State four such features [4] (e) Zara wants to save the contents of the data structure Puzzle to a sequential file Puzzle.TXT Write program code for the procedure SavePuzzleToFile(Puzzle). Programming language... Code [5] 9691/22/M/J/16

79 15 (f) One of Zara s friends suggests that the number of squares for a word should be counted. Zara decides that she needs a function to count the number of squares for a word going across. She needs another function to count the number of squares for a word going down. The program will call the function CountSquaresAcross when ThisRow and ThisColumn refer to a square that is the start of a word across. Write pseudocode for the function CountSquaresAcross. Declare any local variables required. FUNCTION CountSquaresAcross(Puzzle, ThisRow, ThisColumn) RETURNS INTEGER... [7] 9691/22/M/J/16

80 16 BLANK PAGE 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. To avoid the issue of disclosure of answer-related information to candidates, all copyright acknowledgements are reproduced online in the Cambridge International Examinations Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at after the live examination series. 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. 9691/22/M/J/16

81 Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level * * COMPUTING 9691/23 Paper 2 May/June hours 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 an HB pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, glue or correction fluid. DO NOT WRITE IN ANY BARCODES. Answer all questions. 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. This document consists of 16 printed pages. DC (LK/JG) /3 [Turn over

82 2 1 Zara wants to write a temperature conversion program. The program is to output a table to show Fahrenheit temperatures and their Celsius equivalents. She writes the program specification: input lower bound and upper bound of Fahrenheit temperatures (whole numbers only) input temperature interval (whole number only) output conversion table (Celsius temperatures rounded to the nearest whole number) Example conversion table with lower bound 50, upper bound 90 and interval 5: Conversion Table Fahrenheit Celsius : : : : The steps to convert a Fahrenheit temperature to a Celsius temperature are: subtract 32 from the Fahrenheit temperature multiply by 5 divide by 9 (i) Zara writes pseudocode that uses the variables in the identifier table below. Complete the identifier table. Identifier Data type Explanation LowerTemp UpperTemp Interval Fahrenheit Result Lower bound value of Fahrenheit temperatures Upper bound value of Fahrenheit temperatures The interval between two successive Fahrenheit temperatures in the table The Fahrenheit temperature value to be converted Value of conversion to Celsius before rounding Celsius The rounded Result [2] 9691/23/M/J/16