Cambridge IGCSE Computer Science (9-1) 0984 — 2025 May/June Paper 1 · Variant 1

This document has 12 pages. Any blank pages are indicated. [Turn over Cambridge IGCSE™(9–1) COMPUTER SCIENCE 0984/11 Paper 1 Computer Systems May/June 2025 1 hour 45 minutes You must answer on the question paper. No additional materials are needed. INSTRUCTIONS ● Answer all questions. ● Use a black or dark blue pen. You may use an HB pencil for any diagrams or graphs. ● Write your name, centre number and candidate number in the boxes at the top of the page. ● Write your answer to each question in the space provided. ● Do not use an erasable pen or correction fluid. ● Do not write on any bar codes. ● Calculators must not be used in this paper. INFORMATION ● The total mark for this paper is 75. ● The number of marks for each question or part question is shown in brackets [ ]. ● No marks will be awarded for using brand names of software packages or hardware. * 9 9 8 8 9 1 8 9 0 4 * DC (PQ) 353938 © UCLES 2025 ,










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2 0984/11/M/J/25 © UCLES 2025 1 The size of a file can be measured using different data storage units. (a) Tick (3) one box to show the smallest data storage unit. A byte B gibibyte (GiB) C kibibyte (KiB) D nibble [1] (b) State how many tebibytes (TiB) are equal to 2 pebibytes (PiB). … [1] Working space … … … (c) The size of a file needs to be reduced. (i) Give the name of the process that is used to reduce the size of a file. … [1] (ii) One reason the size of a file may need reducing is so that it has a shorter transmission time. Give one other reason why the size of a file may need reducing. … … [1] 2 A clothes store has a ticket system to allow customers to speak to a personal shopper. The ticket displays a ticket number in hexadecimal, for example 11B. (a) The ticket system has an output device that creates a paper ticket. Identify an appropriate output device to produce the paper ticket. … [1] * 0000800000002 * ,










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3 0984/11/M/J/25 © UCLES 2025 [Turn over (b) Each ticket number is stored as a binary number in the ticket machine. (i) Two ticket numbers are 14B and 97A. Convert the two ticket numbers from hexadecimal to binary. 14B … 97A … [2] Working space … … … … (ii) Give two reasons why the ticket number is displayed as hexadecimal instead of binary. 1 … … 2 … … [2] (c) The ticket numbers could also be represented as denary. (i) Convert the two ticket numbers from hexadecimal to denary. 02C … 10B … [2] (ii) Convert the two denary numbers into hexadecimal. 109 … 415 … [2] Working space … … … … * 0000800000003 * ,










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4 0984/11/M/J/25 © UCLES 2025 3 An image is converted to binary to be represented by a computer. Complete the table with the missing terms and definition about representing an image. Term Definition … This is the smallest component of an image. resolution … … … … This is the number of bits used to create each colour in an image. … This is additional data that is stored with an image that can provide information such as the time and date the image was taken. [4] 4 A restaurant has an electronic ordering system. The system allows customers to select the food they want to order. The data for the order is transmitted across their network to a computer in the restaurant kitchen. (a) The data is sent using serial full-duplex data transmission. (i) Give two reasons why serial full-duplex is a suitable data transmission method for the data. 1 … … 2 … … [2] (ii) Give one improvement that would be made to the data transmission if parallel transmission is used instead of serial transmission. … … [1] * 0000800000004 * ,










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5 0984/11/M/J/25 © UCLES 2025 [Turn over (b) A checksum is used to check the data for errors after transmission. (i) Describe the process of the checksum error detection method. … … … … … … … … … … [5] (ii) Identify one other error detection method that could be used to check for errors in the data. … [1] (c) A customer can also order food from home using the internet. The data for their order is broken down into packets and transmitted across the internet to the computer in the restaurant kitchen. (i) Tick (3) one box to show which item would not be included in a packet’s header. A destination address B originator’s address C packet number D payload [1] (ii) The packets of data may need to be reordered when they arrive at the computer in the restaurant kitchen. Explain why the packets of data may need to be reordered. … … … … [2] * 0000800000005 * ,










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6 0984/11/M/J/25 © UCLES 2025 5 Data is processed by the central processing unit (CPU) in a computer that has a Von Neumann architecture. (a) Complete the table with the missing terms and definitions about processing data. Term Definition current instruction register (CIR) … … … … This is a processing unit within the CPU that can fetch, decode and execute instructions. … This is a list of all the commands that can be processed by the CPU. cache … … … accumulator … … … [5] (b) Identify the component in the CPU that is responsible for decoding an instruction. … [1] (c) Explain how the clock speed can affect the performance of a CPU. … … … … … … [3] * 0000800000006 * ,










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7 0984/11/M/J/25 © UCLES 2025 [Turn over 6 Data can be encrypted using asymmetric encryption. (a) Complete the paragraph about asymmetric encryption. Use the terms from the list. Some of the terms in the list will not be used. You may use a term more than once. algorithm binary cipher text compression error hardware hexadecimal meaningless plain text private public readable transmission unreadable Data is encrypted using an encryption key. This is a type of … that scrambles the … and turns it into … . This makes the data … . A … key is used to encrypt the data. This key cannot be used to decrypt the data. A … key is used to decrypt the data. Any device is able to request the … key, but only your device knows the … key. [8] (b) Data can also be encrypted using symmetric encryption. Give one reason why a person would use asymmetric encryption instead of symmetric encryption. … … [1] * 0000800000007 * ,










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8 0984/11/M/J/25 © UCLES 2025 7 A student’s computer has primary storage. One example of primary storage is random access memory (RAM). (a) Identify one other example of primary storage. … [1] (b) Explain why RAM is an example of primary storage and not secondary storage. … … … … … … [3] (c) The student is editing a large video file for a project and during this process the RAM becomes full. This makes the computer crash. Describe how virtual memory could be used in this process to stop the computer crashing. … … … … … … [3] (d) The computer uses solid-state (flash memory) storage. (i) Give two features of solid-state (flash memory) storage. 1 … … 2 … … [2] (ii) Give two examples of solid-state (flash memory) storage. 1 … 2 … [2] * 0000800000008 * ,










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9 0984/11/M/J/25 © UCLES 2025 [Turn over 8 A robot is used to move car parts in a factory. (a) One characteristic of the robot is that it has a mechanical structure. Give one other characteristic of a robot. … … [1] (b) The robot has firmware. State what is meant by firmware. … … [1] (c) Interrupts are generated when the robot is operating in the factory. Give two examples of interrupts that may be generated when the robot is in operation. 1 … 2 … [2] (d) Give two advantages to the workers in the factory of using robots to move the car parts. 1 … … 2 … … [2] (e) The robots have the ability to automatically adapt their own processes. State the name of the ability described. … [1] * 0000800000009 * ,










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10 0984/11/M/J/25 © UCLES 2025 9 Each employee in a finance company has a computer and an electronic account. (a) Each computer has an operating system. One function of the operating system is to manage memory. Describe the role of the operating system in managing memory. … … … … … … [3] (b) The finance company is concerned that a hacker may perform a brute-force attack to gain access to an employee’s account. (i) Describe how the hacker would perform the brute-force attack. … … … … [2] (ii) Give three cyber security solutions that could be used to help prevent a brute-force attack from being successful. 1 … 2 … 3 … [3] (c) The company uses a digital currency to purchase a new car. (i) State what is meant by a digital currency. … … [1] (ii) The digital currency uses a process that involves a digital ledger. The ledger has time stamped transactions that cannot be altered. Give the name of this process. … [1] * 0000800000010 * ,










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12 0984/11/M/J/25 © UCLES 2025 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 Cambridge Assessment. Cambridge Assessment is the brand name of the University of Cambridge Local Examinations Syndicate (UCLES), which is a department of the University of Cambridge. BLANK PAGE * 0000800000012 * ,









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This document consists of 13 printed pages. © Cambridge University Press & Assessment 2025 [Turn over Cambridge IGCSE™ (9–1) COMPUTER SCIENCE 0984/11 Paper 1 Theory May/June 2025 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 May/June 2025 series for most Cambridge IGCSE, Cambridge International A and AS Level components, and some Cambridge O Level components.

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 2 of 13 Generic Marking Principles These general marking principles must be applied by all examiners when marking candidate answers. They should be applied alon gside the specific content of the mark scheme or generic level descriptions 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.

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 3 of 13 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 thre sholds or grade descriptors in mind.

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 4 of 13 Annotations guidance for centres Examiners use a system of annotations as a shorthand for communicating their marking decisions to one another. Examiners are trained during the standardisation process on how and when to use annotations. The purpose of annotations is to inform the standard isation and monitoring processes and guide the supervising examiners when they are checking the work of examiners within their team. The meaning of annotations and how they are used is specific to each component and is understood by all examiners who mark the component. We publish annotations in our mark schemes to help centres understand the annotations they may see on copies of scripts. Note that there may not be a direct correlation between the number of annotations on a script and the mark awarded. Similarly, the use of an annotation may not be an indication of the quality of the response. The annotations listed below were available to examiners marking this component in this series. Annotations Annotation Meaning Correct point Incorrect point Unclear response Follow through Repetition Ignore Benefit of doubt given Benefit of doubt not given Content of response too vague Not answered question

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 5 of 13 Annotation Meaning Omission Section not relevant Section incorrect Highlighter Information copied from the text Page or response seen by examiner Annotation guidance: / separates alternative words or phrases within a marking point // separates alternative answers within a marking point Underline actual word given must be used by candidate (grammatical variants accepted) Max indicates the maximum number of marks that can be awarded ( ) the word / phrase in brackets is not required, but sets the context Note: No marks are awarded for using brand names of software packages or hardware

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 6 of 13 Question Answer Marks 1(a) D 1 1(b) 2048 1 1(c)(i) (Data) Compression 1 1(c)(ii) Any one from: • Less bandwidth required to transmit the file • Less storage space needed to store the file • To meet email file size limit • To use less data allowance 1 Question Answer Marks 2(a) Printer 1 2(b)(i) 0001 0100 1011 1001 0111 1010 2 2(b)(ii) Any two from: • Easier/quicker for the customer to understand/read/remember • Takes up less space on the ticket // Shorter representation 2 2(c)(i) 44 267 2 2(c)(ii) (0)6D 19F 2

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 7 of 13 Question Answer Marks 3 One mark for each correct term or definition. Term Definition pixel It is the smallest component of an image. resolution The number of pixels high by the number of pixels wide // The number of pixels in an image colour depth // bit depth This is the number of bits that are used to create each colour in an image. metadata // header This is additional data that is stored with an image that can provide information such as the time and date the image was taken. 4 Question Answer Marks 4(a)(i) Two from (one mark for serial, one mark for full-duplex): serial • Serial is suitable as data may be travelling a long distance (over 5 metres). • Serial is suitable to make sure that bits don’t arrive skewed/arrives in order. • Serial is suitable as there is less chance of error. • Serial has sufficient transmission speed as not much data being sent. full-duplex • Full-duplex is suitable as data needs to go between customer and kitchen computer // data needs to go in both directions // so notification of errors can be sent back to customer. 2 4(a)(ii) The data may be transmitted faster. 1

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 8 of 13 Question Answer Marks 4(b)(i) Any five from: • The checksum is calculated from/using the data. • … using an algorithm // by example. • The (checksum) value is transmitted with the data. • The (checksum) value is recalculated after transmission/by recipient. • If the checksum values do not match, an error is detected // If the checksum values match, no error is detected … • … request for data to be resent if there is an error. 5 4(b)(ii) Any one from: • Parity byte/block check • Echo check 1 4(c)(i) D 1 4(c)(ii) Any Two from: • The packets arrive in the wrong order. • Each packet could take a different route. • Some packets may take longer than others to be transmitted. • Some packets may not arrive/be corrupted and need to be requested again. 2

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 9 of 13 Question Answer Marks 5(a) Term Definition current instruction register (CIR) stores the instruction that is being decoded/executed core This is a processing unit within the CPU that can fetch, decode and execute instructions. instruction set This is a list of all the commands that can be processed by the CPU. cache stores frequently used data/instructions accumulator stores the result of interim calculations 5 5(b) Control unit // CU 1 5(c) Three from: • On each clock pulse, an FDE cycle is performed. • The clock speed is the number of FDE cycle performed in a second // The clock speed is the number of times the clock pulses per second/per unit of time. • If clock speed is increased more FDE cycles can be performed in a second // If clock speed is decreased fewer FDE cycles can be performed in a second. • If clock speed is increased, it can improve the performance of the CPU // If clock speed is decreases it decreases the performance of the CPU. 3

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 10 of 13 Question Answer Marks 6(a) One mark for each correct term in the correct position • algorithm • plain text • cipher text • meaningless • public/private • private/public (must be opposite of MP5) • public • private Data is encrypted using an encryption key. This is a type of algorithm that scrambles the plain text and turns it into cipher text. This makes the data meaningless. A public/private key is used to encrypt the data. This key cannot be used to decrypt the data. A private/public key is used to decrypt the data. Any device is able to request the public key, but only your device knows the private key. 8 6(b) Any one from: • The process is more secure. • Do not need to worry about key exchange. 1

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 11 of 13 Question Answer Marks 7(a) Any one from: • Read only memory // ROM • Cache 1 7(b) Any three from: • RAM is directly accessed by the CPU. • … whereas secondary storage is not directly accessed by the CPU. • All secondary storage is non-volatile storage. • … whereas RAM is volatile storage. 3 7(c) Any three from: • Virtual memory can act as an extension to the RAM . • The secondary storage device is partitioned to create the virtual memory. • Pages can be transferred from the RAM to the virtual memory … • … to stop the RAM getting full // … when the RAM is full. 3 7(d)(i) Any two from: • It has no moving parts. • It uses semiconductor chips. • It uses NAND/NOR/Flip-flops technology. • It uses cells and transistors (that are laid out in a grid). • It uses control gates and floating gates. • Stores data as electrical charges. 2 7(d)(ii) Any two from: • Solid-state drive // SSD • USB flash memory drive • SD card 2

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 12 of 13 Question Answer Marks 8(a) Any one from: • It has electrical components. // by example • It is programmable. • It can move. 1 8(b) Any one from: • Permanent instructions/software that are programmed into/stored in the ROM. • Instructions/software that allow hardware to be controlled/managed. • Instructions/software that provides the operating system with a platform to run on. 1 8(c) Any two from: Examples: • user input // by example • encountering an obstacle • emergency stop • hardware error • software error • battery low • component overheating • two processes accessing the same location 2 8(d) Any two from: Examples: • Workers don’t need to lift heavy machinery • The workers are less likely to injure themselves • The workers don’t need to be in any dangerous environments in the factory • The workers don’t need to perform boring/repetitive tasks such as moving car parts • Workers can focus on having higher expertise skills • Create new jobs for workers to maintain the robots. 2

0984/11 Cambridge IGCSE (9–1) – Mark Scheme PUBLISHED May/June 2025 © Cambridge University Press & Assessment 2025 Page 13 of 13 Question Answer Marks 8(e) Machine learning 1 Question Answer Marks 9(a) Any three from: Examples: • To make sure memory is used efficiently • Allocates/deallocates memory to processes • Checks that the processes being actioned have enough memory available • Moves data to and from memory/between memory and storage • Makes sure that two processes do not try and access the same memory location • Creates a memory partition • Creates virtual memory • Transmits pages between RAM and VM 3 9(b)(i) Any two from: • Try to find out/guess a password • … by repeatedly entering different combinations/passwords • Could use software to do it automatically 2 9(b)(ii) Any three from: • Strong passwords // passwords that are long and have a combination of letters, numbers and symbols • Two-step verification // two-factor authentication • Biometric password • Limiting the number of login attempts 3 9(c)(i) A currency that only exists electronically/virtually 1 9(c)(ii) Blockchain 1