9608_s21_qp_12
A paper of Computer Science, 9608
Questions:
9
Year:
2021
Paper:
1
Variant:
2
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2
The following diagram shows four register notations and seven descriptions. Draw one line from each register notation to its most appropriate description. Register notation Description MDR CIR MAR PC Holds the op code and operand of an instruction ready for it to be decoded Holds the address of the next instruction to be read Holds flags that are set when the Arithmetic and Logic Unit (ALU) executes instructions Holds data read from, or to be written to, memory Holds the current value in the Index Register Holds the address where data is to be written to or read from Holds the result of the last instruction executed by the ALU
1. Theory Fundamentals  →  1.4. Processor fundamentals
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3
The table shows part of the instruction set for a processor. The processor has one general purpose register, the Accumulator (ACC), and an Index Register (. Instruction Explanation Op code Operand LDD Direct addressing. Load the contents of the location at the given address to ACC. LDI Indirect addressing. The address to be used is at the given address. Load the contents of this second address to ACC. STO Store the contents of ACC at the given address. ADD Add the contents of the given address to ACC. INC Add 1 to the contents of the register (ACC or . JMP Jump to the given address. CMP Compare the contents of ACC with the contents of . JPE Following a compare instruction, jump to if the compare was True. END Return control to the operating system. The current contents of the main memory are: Address Instruction LDI 103 CMP 101 JPE 59 ADD 102 STO 102 LDD 100 INC ACC STO 100 JMP 51 ADD 102 STO 102 END … Trace the program currently in memory using the following trace table. Instruction address ACC Memory address The instruction in memory address 50 needs to be changed to use direct addressing to load the contents of the memory location at address 100. Give the new instruction to replace LDI 103. Each instruction in the assembly language program is encoded in 16 bits (8-bit op code followed by an 8-bit operand). The instruction JPE 59 has the operand 59. Convert the operand 59 into 8-bit binary. Convert the denary value 59 into hexadecimal. The assembly language program uses direct and indirect addressing. Identify two other modes of addressing used in an assembly language program.
1. Theory Fundamentals  →  1.4. Processor fundamentals
Open
4
K2 Mountain Guiding is a company that runs courses teaching people how to climb mountains. The company uses a file-based approach to store and retrieve data. Describe three drawbacks of a file-based approach compared to a relational database. Drawback 1 Drawback 2 Drawback 3 Each course has a destination and a trip date, and is run by a guide. Customers can book a place on one or more courses. The following table shows part of the stored file: Customer name Customer date of birth Guide Destination Trip date Jay Patel 10/10/1976 Artem Elbrus 06/03/2023 Paul Schloss 10/04/1999 Kenton K2 01/03/2022 Mina Wang 03/03/2000 Kenton K2 01/03/2022 Paul Schloss 10/04/1999 Safia Mont Blanc 07/07/2024 Jay Patel 10/10/1976 Safia K2 04/04/2023 The company has decided to create a relational database to replace the current file-based approach. Identify three reasons why the data in this table is not in First Normal Form (1NF). The table, GUIDE_TABLE, is created. Each guide has a unique guide ID. Part of the table GUIDE_TABLE is shown: GuideID Guide DateOfBirth Gender Artem 07/03/1992 M Kenton 08/04/1984 M Safia 10/10/1999 F Write a Data Definition Language (DDL) statement to define the table GUIDE_TABLE.
1. Theory Fundamentals  →  1.8. Database and data modelling
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5
A web page includes HTML and JavaScript code. 04 Calculate area of a triangle: 06 Base 07 Height 08 Calculate 12 function area() { 13 var base = document.forms["Triangle"]["B"].value; 14 var height = document.forms["Triangle"]["H"].value; 15 if (base == "" || height == "") { 16 alert("Both values must be entered"); 17 return false; 18 } 19 else { 20 area = 0.5 * height * base; 21 alert("The area is: " + area); 22 } 23 } Give the three identifiers used in the JavaScript code. State the purpose of the code on line 08. The page is loaded and the values 2 and 8 are entered. State the output when the calculate button is clicked. State the meaning of the || operator in line 15 of the code. Data validation has been used in line 15 of the JavaScript code. Identify the type of data validation used in line 15. Identify two other data validation checks that could be used. Question 5 continues on the next page. Cambridge International Holidays allows customers to make holiday bookings on its website. Bochen visits the Cambridge International Holidays website to book a holiday. The sequence (1 to 8) below describes the steps that take place when he submits a booking. Four of the statements A, B, C, D, E and F are used to complete the sequence. A Any errors found at the server side are flagged, and step 1 is repeated. B HTML code is used on the client’s web browser to validate the form data. C PHP code is executed to generate a confirmation (HTML) web page that is returned to the client’s web browser. D The form data is transmitted to Cambridge International Holidays’ web server. E JavaScript code is executed to generate a confirmation (HTML) web page that is returned to the client’s web browser. F JavaScript code is executed on the client’s web browser to validate the form data. Write one of the letters (A, B, C, D, E or F) in the appropriate row to complete the sequence. Bochen completes the online booking and clicks ‘Submit’. Any errors found are flagged, and step 1 is repeated. PHP code is executed to perform extra data validation checks on the form data. The booking details are added to the database.
1. Theory Fundamentals  →  1.2. Communication and Internet technologies
Open
6
This question presents three scenarios. Tick (3) one box for each scenario to indicate whether you think the named person’s behaviour is ethical or unethical. Justify your choice. Latifah has changed jobs and has started to work for a new company. The company uses an Integrated Development Environment (IDE) to develop code. Latifah decides not to use the IDE that the company has because she is familiar with a different IDE. Ethical Unethical Justification Samid is in charge of a project to write a banking application. He is employing staff to work on the application. His daughter is a computer security expert. She is looking for a new job. Samid decides to employ his daughter. Ethical Unethical Justification Jason works for a social media company. He is concerned that users of the company’s social media website have not been told how their personal data is being used. Jason tells his manager his concerns. His manager tells him not to worry because there have been no complaints from the users. Jason takes no further action. Ethical Unethical Justification
1. Theory Fundamentals  →  1.7. Ethics and ownership
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7
Sam is a photographer. She has an image library of over 10 000 images. She stores the images on a high capacity magnetic hard disk. Explain why Sam would use the following utility software. Backup Defragmenter Disk repair The images are stored as bitmap files. Identify four items that will be stored in the header of a bitmap file. The bitmap images are compressed for use on a website. Tick (3) one box to select the most appropriate type of compression for the images used on the website and justify your answer. Lossy Lossless Justification
1. Theory Fundamentals  →  1.1. Information representation
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