1 hour 30 minutes You must answer on the question paper. No additional materials are needed. INSTRUCTIONS ● Answer all questions. ● Use a black or dark blue pen. ● 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. ● You may use an HB pencil for any diagrams, graphs or rough working. ● 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. ,



 






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1 (a) A student creates sound recordings. Making changes to a sound recording may impact the accuracy of the resulting sound file or the size of the file. Draw two lines from each change to the impacts it has on the sound file. Impact the file size gets bigger no change in the file size the file size gets smaller the accuracy of the sound file improves no change to the accuracy of the sound file the accuracy of the sound file worsens Change increase the duration of the recording increase the sampling rate decrease the sampling resolution [3] (b) The file names of the sound recordings are stored using the ASCII character set. Explain how text is represented by the ASCII character set. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (c) Give two differences between the ASCII and UNICODE character sets. 1 ................................................................................................................................................ ................................................................................................................................................... ................................................................................................................................................... 2 ................................................................................................................................................ ................................................................................................................................................... ................................................................................................................................................... [2] * 0000800000002 * ,



 






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1 1 0 1 0 1 1 1 1 1 [2] (b) Draw a logic circuit for the logic expression: X = NOT (((A AND B) OR C) AND (C NOR D)) X D C B A [2] * 0000800000004 * ,



 






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1 ................................................................................................................................................ ...................................................................................................................................................

1 ................................................................................................................................................ ................................................................................................................................................... ................................................................................................................................................... ...................................................................................................................................................

1 ................................................................................................................................................ ................................................................................................................................................... ...................................................................................................................................................

1 TO LENGTH(x) IF MID(x, INDEX, 1) = "@" THEN FLAG TRUE ENDIF NEXT INDEX IF NOT FLAG THEN OUTPUT "Invalid" ENDIF [3] * 0000800000014 * ,



 





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1 ................................................................................................................................................ ...................................................................................................................................................

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2 (a) Data in a computer system is represented in binary. Put one tick (3) in each row to identify the minimum number of bits used to store each example of data. Example of data Number of bits

2 ................................................................................................................................................ ...................................................................................................................................................

2 ................................................................................................................................................ ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... [4] * 0000800000008 * ,



 






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2 ................................................................................................................................................ ................................................................................................................................................... ................................................................................................................................................... [4] * 0000800000013 * ,



 





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2 ................................................................................................................................................ ................................................................................................................................................... [2] (b) Explain how a programmer benefits from using program libraries during program development. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (c) A programmer is developing an Operating System (OS). Identify two types of software licence the programmer can use to allow other people to edit and redistribute the OS. 1 ................................................................................................................................................ 2 ............................................................................................................................................... [2] (d) Memory management is one key management task performed by an OS. Give three other key management tasks that are performed by an OS. 1 ................................................................................................................................................ 2 ................................................................................................................................................

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3 (a) Complete the truth table for the following logic expression: X = (A NOR B) NAND (C XOR B) A B C Working space X 0 0 0

3 ................................................................................................................................................ ................................................................................................................................................... [3] (b) Give one drawback of using a wireless network. ................................................................................................................................................... ............................................................................................................................................. [1] (c) Complete the table by writing the name of the type of memory technology for each description. Description Memory technology A read only memory where the contents can be erased using a voltage pulse. The contents can be changed multiple times without physically removing the memory. A read only memory where the contents are erased using ultraviolet (UV) light. The memory must be physically removed to be reprogrammed. A read only memory where the contents can be written only once after manufacture. [3] * 0000800000005 * ,



 






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3 Darwin Acula F No Write a Structured Query Language (SQL) script to define the table STAFF. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4] (c) Products are given a rating between 1 and 10 inclusive. Write an SQL script to return only the ProductID, ProductName and ComplaintDetails for all products with a rating of 5 or less. The results need to be displayed in descending order of rating. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [5] * 0000800000007 * ,



 






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3 ................................................................................................................................................ [3] * 0000800000015 * ,



 





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4 A network engineer is setting up a Local Area Network (LAN) in an office. The network uses both wired and wireless connectivity. (a) Give three advantages of a wireless network compared to a wired network.

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5 A company creates a relational database to store data about its customers. The database, REVIEWS, stores data about the customers, products, complaints and staff. The database has four tables: CUSTOMER(CustomerID, CustomerFirstName, CustomerLastName, CustomerEmail) PRODUCT(ProductID, ProductName, ProductDetail, Price, Rating) COMPLAINT(ComplaintID, ProductID, CustomerID, ComplaintDetails, StaffID) STAFF(StaffID, StaffFirstName, StaffLastName, Department, RemoteWorker) (a) Complete the entity‑relationship (E‑R) diagram for the database REVIEWS. CUSTOMER PRODUCT COMPLAINT STAFF [3] * 0000800000006 * ,



 






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6 The following table shows part of the instruction set for a processor. The processor has two registers: the Accumulator (ACC) and the Index Register (IX). Instruction Explanation Opcode Operand LDM #n Immediate addressing. Load the number n to the ACC AND #n / Bn / &n Bitwise AND operation of the contents of the ACC with the operand AND <address> Bitwise AND operation of the contents of the ACC with the contents of <address> XOR #n / Bn / &n Bitwise XOR operation of the contents of the ACC with the operand XOR <address> Bitwise XOR operation of the contents of the ACC with the contents of <address> OR #n / Bn / &n Bitwise OR operation of the contents of the ACC with the operand OR <address> Bitwise OR operation of the contents of the ACC with the contents of <address> CMP #n Compare the contents of the ACC with number n CMP <address> Compare the contents of the ACC with the contents of <address> LSL #n Bits in the ACC are shifted logically n places to the left. Zeros are introduced on the right‑hand end LSR #n Bits in the ACC are shifted logically n places to the right. Zeros are introduced on the left‑hand end <address> can be an absolute or symbolic address # denotes a denary number, e.g. #127 B denotes a binary number, e.g. B10010001 & denotes a hexadecimal number, e.g. &4A The current contents of main memory are shown: Address Data 0000 0011 1010 1110 1100 1100 1111 1111 1100 1100 * 0000800000010 * ,



 






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7 9618/13/O/N/25 (b) Some example data from the STAFF table is shown. StaffID StaffFirstName StaffLastName Department RemoteWorker

7 A digital video camera records students in a classroom. The data is transferred from the digital video camera over the internet to a server. Artificial Intelligence (AI) is used to analyse the video on the server to identify when students are interacting with the lesson and the teacher. (a) Describe one ethical impact of this use of AI in the classroom. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (b) A video is made of many bitmap images called frames. 30 frames are recorded every second. Each frame is 4000 pixels wide by 3000 pixels high. The video records using 16‑bit colour depth. Calculate an estimate for the file size for one second of the video in gigabytes. Show your working. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... File size ................................ gigabytes [2] (c) Identify and describe one method of data verification that can be used when transferring data from the digital video camera to the server. Method ...................................................................................................................................... Description ................................................................................................................................ ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... [3] * 0000800000012 * ,



 





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8 9618/13/O/N/25 (d) A Database Management System (DBMS) is used to maintain and manage the database. Describe two ways in which the DBMS can be used to ensure the security of the customer data.

8 Compilers and interpreters are used to translate programs written in a high‑level language into a low‑level language. (a) State two disadvantages of using a compiler compared to an interpreter during program development.

9 9618/13/O/N/25 Question 6 starts on the next page. * 0000800000009 * ,



 






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11 9618/13/O/N/25 (a) Complete the table by writing the contents of the ACC after the execution of each instruction. Current contents of the ACC Instruction Contents of the ACC after the execution of the instruction 0000 1111 AND 101 0000 0000 LDM #100 0000 0001 XOR &F1 0001 0001 CMP 101 [4] (b) The Von Neumann model for a computer system uses registers. Describe the role of the Memory Address Register (MAR) and Memory Data Register (MDR) in the fetch‑execute (F‑E) cycle. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [4] (c) Assembly language instructions are grouped. Complete each statement by writing the name of the appropriate instruction group. Loading data into the accumulator is an example of an instruction in the ............................................................... group. Incrementing the index register is an example of an instruction in the ............................................................... group. Branching to another address is an example of an instruction in the ............................................................... group. [3] * 0000800000011 * ,



 





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13 9618/13/O/N/25 (d) Describe two reasons why the server that stores the videos uses magnetic hard disks instead of solid state (flash) memory.

14 9618/13/O/N/25 (e) The table contains three algorithms that perform data validation. The third algorithm uses the functions MID and LENGTH. The functions MID and LENGTH are defined as follows: • MID(ThisString : STRING, x : INTEGER, y : INTEGER) RETURNS STRING returns a string of length y starting at position x from ThisString • LENGTH(ThisString : STRING) RETURNS INTEGER returns the integer value representing the length of ThisString Complete the table to identify the method of data validation for each algorithm. Each method of data validation must be different. Algorithm Method of data validation INPUT x IF x < 1 or x > 26 THEN OUTPUT "Invalid" ENDIF INPUT x IF x <> 'R' AND x <> 'G' AND x <> 'B' THEN OUTPUT "Invalid" ENDIF INPUT x FLAG FALSE FOR INDEX

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16 9618/13/O/N/25 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 * 0000800000016 * ,



 





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24 64 the hexadecimal value F139 16 000 000 unique amplitude values an IPv4 address 256 unique colours an IPv6 address the denary value 65 000 [3] (b) Convert the denary number –108 into a 12‑bit two’s complement binary number. ............................................................................................................................................. [1] (c) A three‑place arithmetic shift to the right is performed on the following two’s complement negative integer. Show the result of this arithmetic shift. 10010011 ............................................................................................................................................. [1] (d) Convert the following positive binary integer into hexadecimal. 1110001100111011 ............................................................................................................................................. [1] * 0000800000003 * ,



 






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