Cambridge A Level Computer Science 9608 — 2017 May/June Paper 1 · Variant 1

This document consists of 15 printed pages and 1 blank page. DC (NH/FC) 129906/4 © UCLES 2017 [Turn over * 9 4 5 0 3 2 9 4 9 1 * COMPUTER SCIENCE 9608/11 Paper 1 Theory Fundamentals May/June 2017 1 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 in the spaces at the top of this page. 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. The maximum number of marks is 75. Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level

2 9608/11/M/J/17 © UCLES 2017 1 A hospital is divided into two areas, Area A and Area B. Each area has several wards. All the ward names are different. A number of nurses are based in Area A. These nurses always work on the same ward. Each nurse has a unique Nurse ID of STRING data type. A-NURSE A-WARD (a) Describe the relationship shown above. … …[1] (b) A relational database is created to store the ward and nurse data. The two table designs for Area A are: A-WARD(WardName, NumberOfBeds) A-NURSE(NurseID, FirstName, FamilyName, …) (i) Complete the design for the A-NURSE table. [1] (ii) Explain how the relationship in part (a) is implemented. … … … …[2] (c) In Area B of the hospital, there are a number of wards and a number of nurses. Each Area B ward has a specialism. Each Area B nurse has a specialism. A nurse can be asked to work in any of the Area B wards where their specialism matches with the ward specialism. The relationship for Area B of the hospital is: B-NURSE B-WARD (i) Explain what the degree of relationship is between the entities B-NURSE and B-WARD. … …[1]

3 9608/11/M/J/17 © UCLES 2017 [Turn over (ii) The design for the Area B data is as follows: B-NURSE(NurseID, FirstName, FamilyName, Specialism) B-WARD(WardName, NumberOfBeds, Specialism) B-WARD-NURSE( … ) Complete the attributes for the third table. Underline its primary key. [2] (iii) Draw the relationships on the entity-relationship (E-R) diagram. B-NURSE B-WARD B-WARD-NURSE [2] (d) Use the table designs in part (c)(ii). (i) Write an SQL query to display the Nurse ID and family name for all Area B nurses with a specialism of ‘THEATRE’. … … …[3] (ii) Fatima Woo is an Area B nurse with the nurse ID of 076. She has recently married, and her new family name is Chi. Write an SQL command to update her record. UPDATE … SET … WHERE … [3]

4 9608/11/M/J/17 © UCLES 2017 2 (a) (i) The following sequence of steps (1 to 7) describe how a single page is printed on a laser printer. The statements A, B, C and D are used to complete the sequence. A The paper passes through a fuser, which heats up the paper. The toner melts and forms a permanent image on the paper. B The electrical charge is removed from the drum and the excess toner is collected. C The image is converted on the drum into an electrostatic charge. D The oppositely-charged paper picks up the toner particles from the drum. After picking up the toner, the paper is discharged to stop it clinging to the drum. Complete the sequence by writing one of the letters A, B, C or D on the appropriate row. 1. A laser beam and a rotating mirror are used to draw an image of the page on the photosensitive drum. 2. … 3. Electrostatic charge attracts toner. 4. The charged paper is rolled against the drum. 5. … 6. … 7. … [3] (ii) A computer user has a laser printer to print letters and documents. The user also prints digital photographs taken using a digital camera. State the most suitable type of printer for printing the photographs. …[1] (b) The user is considering the purchase of a new laptop computer. She has read many product reviews and knows that there are different types of internal secondary storage available. List two options for internal secondary storage. Option 1 … Option 2 … Describe one advantage of one of the options. Advantage of choosing option 1 / 2 (circle) … …[3]

5 9608/11/M/J/17 © UCLES 2017 [Turn over Question 3 begins on page 6.

6 9608/11/M/J/17 © UCLES 2017 3 (a) A computer has a microphone and captures a voice recording using sound recording software. Before making a recording, the user can select the sampling rate. Define the term sampling rate. Explain how the sampling rate will influence the accuracy of the digitised sound. Sampling rate … … … Explanation … … [2] (b) The computer also has bitmap software. (i) Define the terms pixel and screen resolution. Pixel … … Screen resolution … … [2] (ii) A picture has been drawn and is saved as a monochrome bitmap image. State how many pixels are stored in one byte. …[1] (iii) A second picture has width 2048 pixels and height 512 pixels. It is saved as a 256-colour image. Calculate the file size in kilobytes. Show your working. … … … … … …[3]

7 9608/11/M/J/17 © UCLES 2017 [Turn over (iv) The actual bitmap file size will be larger than your calculated value. State another data item that the bitmap file stores in addition to the pixel data. … …[1]

8 9608/11/M/J/17 © UCLES 2017 4 The following table shows part of the instruction set for a processor. The processor has one general purpose register, the Accumulator (ACC) and an Index Register (IX). Instruction Explanation Op code (mnemonic) Operand Op code (binary) LDM #n 0000 0001 Immediate addressing. Load the denary number n to ACC. LDD <address> 0000 0010 Direct addressing. Load the contents of the location at the given address to ACC. LDI <address> 0000 0101 Indirect addressing. At the given address is the address to be used. Load the contents of this second address to ACC. LDX <address> 0000 0110 Indexed addressing. Form the address from <address> + the contents of the Index Register (IX). Copy the contents of this calculated address to ACC. LDR #n 0000 0111 Immediate addressing. Load number n to IX. STO <address> 0000 1111 Store the contents of ACC at the given address. The following diagram shows the contents of a section of main memory and the Index Register (IX). (a) Show the contents of the Accumulator (ACC) after each instruction is executed. IX 0 0 0 0 0 0 1 1 (i) LDM #500 ACC …[1] (ii) LDD 500 ACC …[1] (iii) LDX 500 ACC …[1] (iv) LDI 500 ACC …[1] Address Main Memory contents 495 13 496 86 497 92 498 486 499 489 500 496 501 497 502 499 503 502

9 9608/11/M/J/17 © UCLES 2017 [Turn over (b) Each machine code instruction is encoded as 16-bits (8-bit op code followed by an 8-bit operand). Write the machine code for the following instructions: LDM #17 LDX #97 [3] (c) Using an 8-bit operand, state the maximum number of memory locations, in denary, that can be directly addressed. …[1] (d) Computer scientists often write binary representations in hexadecimal. (i) Write the hexadecimal representation for this instruction: 0 0 0 0 0 1 1 1 1 1 0 0 0 0 1 0 …[2] (ii) A second instruction has been written in hexadecimal as: 05 3F Write the equivalent assembly language instruction, with the operand in denary. …[2]

10 9608/11/M/J/17 © UCLES 2017 5 A computer receives data from a remote data logger. Each data block is a group of 8 bytes. A block is made up of seven data bytes and a parity byte. Each data byte has a parity bit using odd parity. The parity byte also uses odd parity. The following table shows a data block before transmission. Bit position 0 is the parity bit. Bit position Data bytes Parity byte 0 1 1 0 1 1 0 0 7 6 5 4 3 2 1 0 1 1 0 0 1 1 0 1 0 0 1 0 0 0 0 0 1 0 0 1 1 1 0 A 1 1 0 0 0 0 1 0 1 1 0 0 0 0 1 0 1 1 0 0 0 1 1 B 0 0 0 0 0 0 0 0 (a) (i) Describe how the data logger calculates the parity bit for each of the bytes in the data block. … … …[2] (ii) State the two missing parity bits labelled A and B. A = … B = … [1] (iii) Describe how the computer uses the parity byte to perform a further check on the received data bytes. … … …[2]

11 9608/11/M/J/17 © UCLES 2017 [Turn over (b) (i) A second data block is received as shown in the following table. There are errors in this data block. Identify and then circle two bits in the table which must be changed to remove the errors. Bit position 0 1 0 1 1 0 0 0 7 6 5 4 3 2 1 0 1 0 0 0 1 1 0 0 0 0 1 0 0 0 0 0 0 0 1 1 0 1 0 1 1 1 1 1 0 0 0 1 1 1 0 0 0 0 1 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 1 [2] (ii) Explain how you arrived at your answers for part (b)(i). … … … …[3]

12 9608/11/M/J/17 © UCLES 2017 6 (a) The operating system (OS) contains code for performing various management tasks. The appropriate code is run when the user performs various actions. Draw a line to link each OS management task to the appropriate user action. Main memory management Input/Output management Secondary storage management Human computer interface management The user moves the mouse on the desktop The user closes the spreadsheet program The user selects the Save command to save their spreadsheet file The user selects the Print command to output their spreadsheet document OS management task Action [3] (b) A user has the following issues with the use of his PC. State the utility software which should provide a solution. (i) The hard disk stores a large number of video files. The computer frequently runs out of storage space. Utility software solution …[1] (ii) The user is unable to find an important document. He thinks it was deleted in error some weeks ago. This must not happen again. Utility software solution …[1] (iii) The operating system reports ‘Bad sector’ errors. Utility software solution …[1] (iv) There have been some unexplained images and advertisements appearing on the screen. The user suspects it is malware. Utility software solution …[1]

13 9608/11/M/J/17 © UCLES 2017 [Turn over 7 The design of a web-based application can require the use of client-side scripting. (a) Describe what is meant by client-side scripting. … … … …[2] (b) A user requests a web page by keying the Uniform Resource Locator (URL) into the address bar of their web browser. The requested page contains a client-side script. Describe the sequence of steps leading to the display of the web page on the computer screen. … … … … … … … …[4]

14 9608/11/M/J/17 © UCLES 2017 (c) A web page used for data capture consists of: • two text boxes for the entry of: • a product code • the number of items to be purchased. • a button which is clicked when the user wants to submit this order. Study the following web page. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 <html> <head> <title>Untitled Document</title> <script language="JavaScript"> function myButton_onmousedown() { var Message1 = "ERROR – Order refused"; var Message2 = "Product code OK"; var x = document.forms["form1"]["txtProductCode"].value; if (x == "") { alert(Message1) } else { alert(Message2) } } </script> </head> <body> <form name = form1> <label>Product code: </label> <input type="text" name="txtProductCode" > <label>Number: </label> <input type="text" name="txtNumber" size = "5" > <p> <label>Submit order: </label> <input type="button" name="btnSubmit" Value = "Submit" onMouseDown = "myButton_onmousedown()" > </p> </form> </body> </html>

15 9608/11/M/J/17 © UCLES 2017 (i) The developer has used three variables in the JavaScript code. State the identifiers used. 1 … 2 … 3 … [2] (ii) The button has an event whose identifier is onMouseDown. When the submit button is clicked, some code is executed. State the line numbers that contain this code. From line … to line … [1] (iii) The JavaScript code uses a selection statement. State the line number that contains the condition. Line number: … [1] (iv) Describe the purpose of the validation check that the code performs. … …[1] (v) Name and describe two other types of validation check that could be appropriate for this data capture form. Validation check: … Description … … Validation check: … Description … … [4]

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® IGCSE is a registered trademark. This document consists of 8 printed pages. © UCLES 2017 [Turn over Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level COMPUTER SCIENCE 9608/11 Paper 1 Written Paper May/June 2017 MARK SCHEME Maximum Mark: 75 Published 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 should be read in conjunction with the question paper and the Principal Examiner Report for Teachers. Cambridge will not enter into discussions about these mark schemes. Cambridge is publishing the mark schemes for the May/June 2017 series for most Cambridge IGCSE®, Cambridge International A and AS Level and Cambridge Pre-U components, and some Cambridge O Level components.

9608/11 Cambridge International AS/A Level – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 2 of 8 Question Answer Marks 1(a) Many-to-one 1 1(b)(i) A-NURSE(NurseID, FirstName, FamilyName, WardName) 1 1(b)(ii) • The primary key WardName in the A-WARD table « 1 • « links to the foreign key WardName in the A-NURSE table. 1 2 1(c)(i) Many-to-many relationship 1 1(c)(ii) B-WARD-NURSE(WardName, NurseID) Both attributes (with no additions) 1 Joint primary key correctly underlined 1 2 1(c)(iii) B-WARD-NURSE B-NURSE B-WARD Correct relationship between B-NURSE and B-WARD-NURSE 1 Correct relationship between B-WARD and B-WARD-NURSE 1 2 1(d)(i) SELECT NurseID, FamilyName 1 FROM B-NURSE 1 WHERE Specialism = 'THEATRE'; 1 3 1(d)(ii) UPDATE B-NURSE 1 SET FamilyName = 'Chi' 1 WHERE NurseID = '076'; 1 3

9608/11 Cambridge International AS/A Level – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 3 of 8 Question Answer Marks 2(a)(i) 1 A laser beam and a rotating mirror are used to draw an image of the page on the photosensitive drum. 2 C // The image is converted on the drum into an electrostatic charge. 3 Electrostatic charge attracts toner. 4 The charged paper is rolled against the drum. 5 D // The oppositely-charged paper picks up the toner particles from the drum. After picking up the toner, the paper is discharged to stop it clinging to the drum. 6 A // The paper passes through a fuser, which heats up the paper. The toner melts and forms a permanent image on the paper. 7 B // The electrical charge is removed from the drum and the excess toner is collected. C in the correct place 1 DA, 1 AB 1 3 2(a)(ii) Inkjet printer 1 2(b) Hard disk drive // HDD 1 Solid state drive //SSD // flash memory 1 One from: Hard disk Inexpensive per unit of storage 1 Larger storage capacity than flash drive 1 Solid state storage No moving parts / noise 1 Robust 1 Low latency // Fast read/write time 1 3

9608/11 Cambridge International AS/A Level – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 4 of 8 Question Answer Marks 3(a) Sampling rate The number of samples taken per unit time // the number of times the amplitude is measured per unit time 1 Increasing the sampling rate will increase the accuracy / precision of the digitised sound // Increasing the sampling rate will result in smaller quantisation errors. 1 2 3(b)(i) Pixel Smallest picture element which can be drawn 1 Screen resolution The number of pixels which can be viewed horizontally and vertically on the screen // or by example - A typical screen resolution is 1680 pixels × 1080 pixels. 1 2 3(b)(ii) 8 1 3(b)(iii) Working: Max two from: • Number of pixels is 2048 × 512 1 • One pixel will be stored as one byte 1 • Number of kilobytes = (2048 × 512) / 1024 1 Answer: One mark: Number of kilobytes = 1024 KB 1 3 3(b)(iv) One from: • Confirmation that the file is a BMP 1 • File size 1 • Location/offset of image data within the file 1 • Dimensions of the image in pixels // image resolution 1 • Colour depth (bits per pixel) 1 • Type of compression used, if any 1 1

9608/11 Cambridge International AS/A Level – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 5 of 8 Question Answer Marks 4(a)(i) 500 1 4(a)(ii) 496 1 4(a)(iii) 502 1 4(a)(iv) 86 1 4(b) 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 1 0 0 0 0 0 1 1 0 0 1 1 0 0 0 0 1 Both correct op codes 1 Operand 0001 0001 1 Operand 0110 0001 1 3 4(c) 256 1 4(d)(i) 07 C2 07 1 C2 1 2 4(d)(ii) LDI 63 LDI 1 63 1 2

9608/11 Cambridge International AS/A Level – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 6 of 8 Question Answer Marks 5(a)(i) • Count the number of one bits in the first seven bit positions 1 • Add a 0 or 1 to bit position 0, to make the count of one bits an odd number 1 2 5(a)(ii) A = 1 B = 1 1 5(a)(iii) Two from: • A parity bit is worked out for each column 1 • The computer checks the parity of each bit position in parity byte // the computer generates copy of the parity byte and compares 1 • If incorrect parity then there is an error in the data received // No parity error means no error in the data received 1 • The position of the incorrect bit can be determined 1 2 5(b)(i) 2 5(b)(ii) Three from: • Consider each row in sequence 1 • Identify any row with incorrect parity 1 • Repeat the process for each column in sequence 1 • Identify where a row and column with incorrect parity intersect 1 3

9608/11 Cambridge International AS/A Level – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 7 of 8 Question Answer Marks 6(a) One mark for each correct line from each left hand box to max three marks. 3 6(b)(i) File compression software 1 6(b)(ii) Backup software 1 6(b)(iii) Disk repair software 1 6(b)(iv) Anti-virus software 1 The user selects the Save command to save their spreadsheet file The user selects the Print command to output their spreadsheet file The user closes the Spreadsheet program

9608/11 Cambridge International AS/A Level – Mark Scheme PUBLISHED May/June 2017 © UCLES 2017 Page 8 of 8 Question Answer Marks 7(a) Two from: • The user’s web browser is the client software 1 • The requested web page has program code / script embedded within it 1 • This code is interpreted by the web browser 1 2 7(b) Four from: • The browser parses the URL to obtain the Domain Name 1 • The browser software passes the Domain Name to the nearest Domain Name Server (DNS) 1 • The DNS stores a list of Domain Names and matching IP addresses 1 • The DNS Name Resolver looks for the Domain Name in its database 1 • If found the corresponding IP address is returned to the originator 1 • If not found the request is forwarded to another higher level DNS 1 • The original DNS adds the returned IP address to its cache 1 • The original DNS returns the IP address to the originator 1 • The browser uses the IP address to request the required web page from the web server 1 • The web server retrieves the page and delivers it to the originator 1 • The browser software interprets the script and displays the web page 1 Max 4 7(c)(i) Message1, Message2 1 x 1 2 7(c)(ii) 6 – 19 1 7(c)(iii) 11 1 7(c)(iv) Checks that the product code has not be left blank // presence check on product code 1 7(c)(v) Two checks from: One mark for check and one mark for description • Range check 1 Check the number entered is (say) between 1 and 100 1 • Format check 1 Checks the product code is a particular format // Checks the number has digit characters only // by example 1 • Length check 1 The number of items has exactly five characters 1 • Existence check 1 To ensure the product code has been assigned 1 Max 4