Cambridge A Level Computer Science 9608 — 2019 Oct/Nov Paper 1 · Variant 2

This document consists of 14 printed pages and 2 blank pages. DC (SC/CB) 171631/1 © UCLES 2019 [Turn over * 5 3 3 9 7 0 9 6 4 6 * COMPUTER SCIENCE 9608/12 Paper 1 Theory Fundamentals October/November 2019 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 Assessment International Education Cambridge International Advanced Subsidiary and Advanced Level

2 9608/12/O/N/19 © UCLES 2019 1 (a) The diagram shows different types of software on the left, and descriptions on the right. Draw a line from each type of software to its correct description. Type of software Description Operating system Utility program Library program Compiler Provides a ready-built routine that can be imported into a program Provides an interface between the user and the hardware Converts source code into a low-level language Creates a new document for the user to edit An additional program that helps to maintain or configure the system [4] (b) Describe the purpose of disk repair software. … … … … … … [3]

3 9608/12/O/N/19 © UCLES 2019 [Turn over 2 (a) Draw a logic circuit to represent the following logic expression: X = NOT (A AND B) AND (C XOR D) A B X D C [4] (b) Complete the truth table for the logic expression: X = NOT (A AND B) OR (A AND (B XOR C)) A B C Working space X 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 [4]

4 9608/12/O/N/19 © UCLES 2019 3 A web page includes the following JavaScript and HTML code. 01 <html> 02 <body> 03 04 <form> 05 <p><input type="text" id="textBox1"></p> 06 <button id = "button1" onclick="multiply()">First</button> 07 <button id = "button2" onclick="addition()">Second</button> 08 </form> 09 10 </body> 11 <script> 12 function multiply(){ 13 value1 = document.getElementById("textBox1").value; 14 value1++; 15 alert(parseInt(value1)* parseInt(value1)); 16 } 17 18 function addition(){ 19 value1 = document.getElementById("textBox1").value; 20 alert(parseInt(value1) + parseInt(value1)); 21 } 22 </script> 23 </html> (a) Name two identifiers used in the JavaScript code. 1 … 2 … [2] (b) The number 9 is typed into textBox1. Write the value that is output after button1 is pressed. … [1] (c) State the purpose of the code in line 14. … … [1]

5 9608/12/O/N/19 © UCLES 2019 [Turn over (d) Line 20 is replaced with: 20 alert(value1 + value1); Describe how this will affect the program. … … … … [2]

6 9608/12/O/N/19 © UCLES 2019 4 Anushka needs to store information about bookings at a sports club. (a) Anushka has a file-based storage system. She wants a relational database. (i) Describe the features of a relational database that address the limitations of Anushka’s file-based system. … … … … … … … … [4] (ii) The relational database design needs to be normalised. The following statements describe the three stages of database normalisation. Complete the statements by filling in the missing words. For a database to be in First Normal Form (1NF) there must be no … groups of attributes. For a database to be in Second Normal Form (2NF), it must be in 1NF, and contain no … key dependencies. For a database to be in Third Normal Form (3NF), it must be in 2NF, and all attributes must be fully dependent on the … … . [4]

7 9608/12/O/N/19 © UCLES 2019 [Turn over (b) The normalised relational database, SPORTS_CLUB, has the following table design. MEMBER(MemberID, FirstName, LastName, MembershipType) SESSION(SessionID, Description, SessionDate, SessionTime, NumberMembers) TRAINER(TrainerID, TrainerFirstName, TrainerLastName) MEMBER_SESSION(MemberID, SessionID) SESSION_TRAINER(SessionID, TrainerID) (i) Anushka has designed an entity-relationship (E-R) diagram for SPORTS_CLUB. Complete the entity-relationship (E-R) diagram. MEMBER MEMBER_SESSION SESSION TRAINER SESSION_TRAINER [2] (ii) Anushka first needs to create the database that she has designed. Write a Data Definition Language (DDL) statement to create the SPORTS_CLUB database. … … [1]

8 9608/12/O/N/19 © UCLES 2019 (iii) The table shows some sample data for the table SESSION. SessionID Description SessionDate SessionTime NumberMembers 21PL Pilates junior 04/04/2020 18:00 15 13AE Aerobics senior 04/04/2020 19:00 20 33WG Weightlifting advanced 04/04/2020 10:00 10 Write a DDL script to create the table SESSION. … … … … … … … … … … [5] (iv) Write a Data Manipulation Language (DML) script to return the first name and last name of all members who have Peak membership type. … … … … … [3]

9 9608/12/O/N/19 © UCLES 2019 [Turn over 5 Mica has created some software and has copyrighted it. She wants to stop other people from copying and changing it illegally. (a) Identify two ways Mica can prevent illegal copies of the software being installed. 1 … … 2 … … [2] (b) Identify one way Mica can distribute the software without the source code. … … [1] (c) Mica is releasing the software under a commercial licence. (i) Give two benefits to Mica of using a commercial licence. 1 … … 2 … … [2] (ii) Name two other types of software licence. 1 … … 2 … … [2]

10 9608/12/O/N/19 © UCLES 2019 6 Dominic uses a tablet computer to complete work. He records videos of his work to send to his colleagues to watch at a later date. (a) The tablet computer has input and output devices. (i) The table lists four devices built into the tablet. Tick (✓) one or more boxes for each device to identify whether it is an input device, an output device or both. Device Input Output Touchscreen Webcam Microphone Fingerprint scanner [2]

11 9608/12/O/N/19 © UCLES 2019 [Turn over (ii) An external speaker is plugged into the tablet computer. The sequence of steps 1 to 7 describes the internal operation of the speaker. The statements A, B, C, D and E are used to complete the sequence. Letter Statement A Changes in the audio signal cause the direction of the electrical current to change. This determines the polarity of the electromagnet. B The vibration creates sound waves. C An electric current is sent to the speaker. D The electromagnet is repelled by, or attracted to the permanent magnet. E The electric current passes through the coil. Write one of the letters A to E in each appropriate row to complete the sequence. 1 … 2 … 3 The current in the coil creates an electromagnetic field. 4 … 5 … 6 The movement of the coil causes the diaphragm to vibrate. 7 … [4]

12 9608/12/O/N/19 © UCLES 2019 (b) The tablet computer’s secondary storage is solid state (flash) memory. (i) Give one reason why the tablet computer needs secondary storage. … … [1] (ii) Describe solid state memory. … … … … … … [3] (c) The tablet computer has RAM and ROM memory. State the purpose of RAM and ROM memory in the computer. RAM … … ROM … … [2] (d) Dominic’s tablet captures a video of Dominic to send to other people. The video is made of a sequence of images and a sound file. (i) Describe how the images and sound are encoded into a digital form. Images … … … … Sound … … … … [4]

13 9608/12/O/N/19 © UCLES 2019 [Turn over (ii) The sequence of images and the sound file create a video. This is sent over the Internet as a video stream. The video stream can use interlaced encoding or progressive encoding. Describe the terms interlaced encoding and progressive encoding. Interlaced encoding … … … … Progressive encoding … … … … [4] (e) Dominic sends his videos to his colleagues over the Internet using bit streaming. (i) Describe how the video is sent using bit streaming. … … … … … … … … [4] (ii) Circle either Real-time or on-demand to identify whether the video will be sent using real-time or on-demand bit streaming. Justify your choice. Real-time / on-demand Justification … … … … [2]

14 9608/12/O/N/19 © UCLES 2019 (iii) Describe the following video terms. Temporal redundancy … … … … Spatial redundancy … … … … [2]

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16 9608/12/O/N/19 © UCLES 2019 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 Assessment International Education Copyright Acknowledgements Booklet. This is produced for each series of examinations and is freely available to download at www.cambridgeinternational.org after the live examination series. Cambridge Assessment International Education is part of the Cambridge Assessment Group. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which itself is a department of the University of Cambridge. BLANK PAGE

This document consists of 10 printed pages. © UCLES 2019 [Turn over Cambridge Assessment International Education Cambridge International Advanced Subsidiary and Advanced Level COMPUTER SCIENCE 9608/12 Paper 1 Written Paper October/November 2019 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 International will not enter into discussions about these mark schemes. Cambridge International is publishing the mark schemes for the October/November 2019 series for most Cambridge IGCSE™, Cambridge International A and AS Level components and some Cambridge O Level components.

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 2 of 10 Generic Marking Principles These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alongside the specific content of the mark scheme or generic level descriptors for a question. Each question paper and mark scheme will also comply with these marking principles. GENERIC MARKING PRINCIPLE 1: Marks must be awarded in line with: • the specific content of the mark scheme or the generic level descriptors for the question • the specific skills defined in the mark scheme or in the generic level descriptors for the question • the standard of response required by a candidate as exemplified by the standardisation scripts. GENERIC MARKING PRINCIPLE 2: Marks awarded are always whole marks (not half marks, or other fractions). GENERIC MARKING PRINCIPLE 3: Marks must be awarded positively: • marks are awarded for correct/valid answers, as defined in the mark scheme. However, credit is given for valid answers which go beyond the scope of the syllabus and mark scheme, referring to your Team Leader as appropriate • marks are awarded when candidates clearly demonstrate what they know and can do • marks are not deducted for errors • marks are not deducted for omissions • answers should only be judged on the quality of spelling, punctuation and grammar when these features are specifically assessed by the question as indicated by the mark scheme. The meaning, however, should be unambiguous. GENERIC MARKING PRINCIPLE 4: Rules must be applied consistently e.g. in situations where candidates have not followed instructions or in the application of generic level descriptors. GENERIC MARKING PRINCIPLE 5: Marks should be awarded using the full range of marks defined in the mark scheme for the question (however; the use of the full mark range may be limited according to the quality of the candidate responses seen). GENERIC MARKING PRINCIPLE 6: Marks awarded are based solely on the requirements as defined in the mark scheme. Marks should not be awarded with grade thresholds or grade descriptors in mind.

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 3 of 10 Question Answer Marks 1(a) 1 mark per correct line 4 1(b) 1 mark per bullet point to max 3 Disk repair: • Checks for any errors / inconsistencies / bad sectors on the disk • Resolves any errors on the disk • Retrieves files / data from a damaged disk // re-constructs directory // recovers disc when data corrupt • Marks bad sectors on the disk // marks bad sectors as unusable 3 Type of software Description An additional program that helps to maintain or configure the system Creates a new document for the user to edit Converts source code into a low-level language Provides an interface between the user and the hardware Provides a ready-built routine that can be imported into a program Compiler Library program Utility program Operating system

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 4 of 10 Question Answer Marks 2(a) 1 mark per gate 4 2(b) 1 mark for each pair of answers A B C Working space X 0 0 0 1 0 0 1 1 0 1 0 1 0 1 1 1 1 0 0 1 1 0 1 1 1 1 0 1 1 1 1 0 4 Question Answer Marks 3(a) 1 mark per bullet point • multiply • addition • value1 2 3(b) 100 1 3(c) To increment the value in value1 (by one) 1

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 5 of 10 Question Answer Marks 3(d) 1 mark per bullet point to max 2 • value1 will still be a string // No conversion to integer • it will concatenate the digits together rather than add • by specific example e.g. if 3 is input, 33 will be output rather than 6 2 Question Answer Marks 4(a)(i) 1 mark per bullet point, max 3 marks from any group to max 4 • Multiple tables are linked together • « which eliminates / reduces data redundancy / duplication • « and increases data integrity / consistency • « which reduces compatibility issues • « so data need only be updated once • « and associated data will be automatically updated // referential integrity can be enforced • « which eliminates unproductive maintenance // which makes it easier to maintain the data • Program-data independence means that • « the structure of data can change and does not affect program • « the structure of programs can change and does not affect data • « the data can be accessed by any appropriate program • Allows concurrent access to data • « by the use of record locking • « by restricting over-writing changes • Complex queries can be more easily written • ... to search / find specific data // specific example related to the sports club • Different users can be given different access rights • « which improves security • Different users can be given different views of the data • ... so they do not see confidential information • « and data privacy is maintained • « accept a valid example related to the sports club 4 4(a)(ii) 1 mark for each word in the correct position For a database to be in First Normal Form (1NF) there must be no repeating groups of attributes. For a database to be in Second Normal Form (2NF), it must be in 1NF, and contain no partial key dependencies. For a database to be in Third Normal Form (3NF), it must be in 2NF, and all attributes must be fully dependent on the primary key. 4

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 6 of 10 Question Answer Marks 4(b)(i) 1 mark for SESSION to MEMBER_SESSION (one-to-many) 1 mark for TRAINER to SESSION_TRAINER (one-to-many) 2 4(b)(ii) CREATE DATABASE SPORTS_CLUB; 1 4(b)(iii) 1 mark per bullet point • CREATE TABLE SESSION and ( ); • SessionID as char(4) / varchar / varchar(4) / text and Description as varchar / varchar(x) / char(x) / text • SessionDate as date and SessionTime as time • NumberMembers as integer / integer(2) / int / int(2) • SessionID set as a Primary Key Example 1: CREATE TABLE SESSION( SessionID Char(4), Description Varchar, SessionDate Date, SessionTime Time, NumberMembers Integer, PRIMARY KEY (SessionID) ); Example 2: CREATE TABLE SESSION( SessionID Char(4)NOT NULL PRIMARY KEY, Description Varchar, SessionDate Date, SessionTime Time, NumberMembers Integer); 5

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 7 of 10 Question Answer Marks 4(b)(iv) 1 mark per bullet point • Select FirstName and comma and LastName • From MEMBER • Where MembershipType = "Peak" SELECT FirstName, LastName FROM MEMBER WHERE MembershipType = "Peak"; 3 Question Answer Marks 5(a) 1 mark per bullet point to max 2 • Encryption • Assign a unique code so it will not install without this // product key • Limit the number of times that version of the software can be installed • Set a time limit within which the software must be installed 2 5(b) • Provide an .exe file // Compile the source code // Use a compiler 1 5(c)(i) 1 mark per benefit to max 2 • So that she can sell the software for a fee // make money from the software • A commercial licence prohibits unauthorised/further copies being made and/or distributed • A commercial licence prohibits any changes to the software 2 5(c)(ii) 1 mark per bullet point to max 2 • Open Source • Free Software • Shareware • Freeware 2

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 8 of 10 Question Answer Marks 6(a)(i) 1 mark for touchscreen being both 1 mark for remaining 3 devices Device Input Output Touchscreen 9 9 Webcam 9 Microphone 9 Fingerprint scanner 9 2 6(a)(ii) 1 mark for any 1 correct letter in the correct position 2 marks for any 2 correct letters in the correct positions 3 marks for any 3 correct letters in the correct positions 4 marks for 5 correct letters in the correct positions C An electric current is sent to the speaker. E The electric current passes through the coil. The current in the coil creates an electromagnetic field. A Changes in the audio signal cause the direction of the electrical current to change. This determines the polarity of the electromagnet. D The electromagnet is repelled by, or attracted to the permanent magnet. The movement of the coil causes the diaphragm to vibrate. B The vibration creates sound waves. 4 6(b)(i) To store files / software long term 1 6(b)(ii) 1 mark per bullet point to max 3 • No moving parts • Solid state memory is non-volatile • Makes use of blocks / arrays of • « Semiconductors // NAND gates // NOR gates // transistors // integrated circuits • SSD Controller manages the components • Uses a grid of columns and rows that has two transistors at each intersection • One transistor is called a floating gate • The second transistor is called the control gate • Memory cells store voltages which can represent either a 0 or a 1 • Essentially the movement of electrons is controlled to read/write • Not possible to overwrite existing data // it is necessary to first erase the old data then write the new data in the same location 3

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 9 of 10 Question Answer Marks 6(c) 1 mark per bullet point to max 2 • RAM stores currently running parts of files / programs / processes / OS • ROM stores boot up instructions / OS kernel // data permanently // store the firmware for the tablet 2 6(d)(i) 1 mark per bullet point to max 4 Max 3 for image Max 3 for sound Images • The images are stored as bitmaps • Each image is made up of pixels • « each pixel is of a single colour • Each colour has a unique binary number • Store the sequence of binary numbers for each image / frame // store the binary value of each pixel Sound • Measure the height/amplitude of the sound wave • A set number of times per second // at regular time intervals • Each amplitude has a unique binary number • Store the sequence of binary numbers for each sample 4 6(d)(ii) 1 mark per bullet point max 2 for each coding term. Interlaced encoding • The data from a single frame are encoded as two separate fields • One containing the data for the even numbered rows / lines and the other has the data for the odd numbered rows / lines • The image is rendered by alternating between the even field and the odd field of each successive frame • The viewer sees data from two frames simultaneously • The rate of picture display (the field rate) is twice the rate of image frame display (the frame rate) • Produces what appears to the eye to be a high refresh rate • Halves the transmission bandwidth requirements Progressive encoding • Stores the data for an entire frame • Displays all the frame data at the same time • The rate of picture display is the same as the frame rate • High bandwidth requirements 4

9608/12 Cambridge International AS/A Level – Mark Scheme PUBLISHED October/November 2019 © UCLES 2019 Page 10 of 10 Question Answer Marks 6(e)(i) 1 mark per bullet to max 3 • The data is compressed before transmitting • The video is transmitted continuously as a series of bits • The video is hosted on a media server • On download, the server sends the data to a buffer on the client computers // The buffer stores the data from the server • The recipient / user’s software receives bit stream from the buffer 4 6(e)(ii) 1 mark for: On-demand 1 mark for justification from: • The video does not need to be broadcast live // the video is already recorded • Dominic’s colleagues will watch the video at a later date // at their convenience 2 6(e)(iii) 1 mark per description Temporal Redundancy • Pixels in a sequence of consecutive video frames have the same value in the same location Spatial Redundancy • A sequence of consecutive pixels in a single video frame have the same value 2