9618_w22_qp_12
A paper of Computer Science, 9618
Questions:
10
Year:
2022
Paper:
1
Variant:
2
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1
Draw one line from each utility software to its most appropriate purpose. Utility software virus checker disk formatter backup defragmentation disk repair Purpose to reorganise files so they are contiguous to scan for malicious program code to decrease the file size to create copies of files in case the original is lost to initialise a disk to check for and fix inconsistencies on a disk Compilers and interpreters translate programs written in a high-level language into a low-level language. State two drawbacks of using a compiler compared to an interpreter during program development. Explain why high-level language programs might be partially compiled and partially interpreted.
5. System Software  →  5.1. Operating Systems
5. System Software  →  5.2. Language Translators
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3
A greenhouse has an automatic window. The window (operates according to the following criteria: Parameter Description of parameter Binary value Condition T Temperature Too high Acceptable W Wind speed Too high Acceptable R Rain Detected Not detected M Manual override On Off The window opens (X = 1) if: • the temperature is too high and the wind speed is acceptable • and • rain is not detected, or the manual override is off. Draw a logic circuit to represent the operation of the window. X T W R M Complete the truth table for the logic expression: X = NOT (A OR B OR C) AND (B NOR C) A B C Working space X Embedded systems contain Read Only Memory (ROM) and Random Access Memory (RAM). Explain the reasons why ROM is used in an embedded system.
3. Hardware  →  3.2. Logic Gates and Logic Circuits
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5
A relational database, GARDEN, has the following tables: OWNER(OwnerID, FirstName, TelephoneNo, TreeID, TreePosition) TREE(TreeID, ScientificName, MaxHeight, FastGrowing) The database is not in Third Normal Form (3NF). Explain how the database can be normalised to 3NF. Write the Structured Query Language (SQL) script to add a new record in the table TREE to store the following data: Attribute Value TreeID LOW_1276 ScientificName Salix_Alba MaxHeight 30.00 FastGrowing TRUE State what is meant by a candidate key in a relational database. Describe, using an example, what is meant by a data dictionary. Describe what is meant by a logical schema.
8. Databases  →  8.1. Database Concepts
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6
A student uses a networked laptop computer to send an email to a colleague. Explain how a digital signature ensures the email is authentic. Describe how a firewall protects the data on the computer. The student records a sound file. Explain the effect of increasing the sampling rate on the accuracy of the sound recording. Explain the effect of decreasing the sampling resolution on the file size of the sound recording.
1. Information representation  →  1.2. Multimedia Sound
6. Security, privacy and data integrity  →  6.1. Data Security
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7
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 (. Instruction Explanation Opcode Operand LDM #n Immediate addressing. Load the number n to ACC LDD Direct addressing. Load the contents of the location at the given address to ACC LDX Indexed addressing. Form the address from + the contents of the index register. Copy the contents of this calculated address to ACC LDR #n Immediate addressing. Load the number n to IX STO Store the contents of ACC at the given address ADD Add the contents of the given address to the ACC ADD #n Add the denary number n to the 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 CMI Indirect addressing. The address to be used is at the given address. Compare the contents of ACC with the contents of this second address JPE Following a compare instruction, jump to if the compare was True JPN Following a compare instruction, jump to if the compare was False END Return control to the operating system can be an absolute or symbolic address # denotes a denary number, e.g. #123 B denotes a binary number, e.g. B01001101 Trace the program currently in memory using the trace table, stopping when line 90 is executed for a second time. Address Instruction LDR #0 LDX 110 CMI 102 JPE 91 CMP 103 JPN 84 ADD 101 STO 101 JMP 86 INC ACC STO 101 LDD 100 INC ACC STO 100 INC IX JMP 76 END … … Instruction address ACC IX Memory address The following table shows another part of the instruction set for the processor. Instruction Explanation Opcode Operand AND #n Bitwise AND operation of the contents of ACC with the operand AND Bitwise AND operation of the contents of ACC with the contents of XOR #n Bitwise XOR operation of the contents of ACC with the operand XOR Bn Bitwise XOR operation of the contents of ACC with the binary number n XOR Bitwise XOR operation of the contents of ACC with the contents of OR #n Bitwise OR operation of the contents of ACC with the operand OR Bitwise OR operation of the contents of ACC with the contents of LSL #n Bits in ACC are shifted logically n places to the left. Zeros are introduced on the right-hand end LSR #n Bits in ACC are shifted logically n places to the right. Zeros are introduced on the left-hand end can be an absolute or symbolic address # denotes a denary number, e.g. #123 B denotes a binary number, e.g. B01001101 The contents of memory addresses 50 and 51 are shown: Memory address Data value The current contents of the ACC are: Show the contents of the ACC after the execution of the following instruction. XOR B00011111 The current contents of the ACC are: Show the contents of the ACC after the execution of the following instruction. AND 50 The current contents of the ACC are: Show the contents of the ACC after the execution of the following instruction. LSL #3 The current contents of the ACC are: Show the contents of the ACC after the execution of the following instruction. OR 51 Write the register transfer notation for each of the stages in the fetch-execute cycle described in the table. Description Register transfer notation Copy the address of the next instruction into the Memory Address Register. Increment the Program Counter. Copy the contents of the Memory Data Register into the Current Instruction Register.
4. Processor Fundamentals  →  4.2. Assembly Language
4. Processor Fundamentals  →  4.1. Central Processing Unit (CPU) Architecture
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8
The following bitmap image has a resolution of 4096 × 4096 pixels and a colour depth of 24 bits per pixel. The image is displayed on a monitor that has a screen resolution of 1920 × 1080 pixels. Tick (3) one box in each row to identify the effect of each action on the image file size. Action Increases the file size Decreases the file size No change to the file size Change the colour depth of the image file to 16 bits per pixel. Change the screen resolution to 1366 × 768 pixels. Change the colour of the rectangle from black to red. State two benefits of creating a vector graphic instead of a bitmap image. A second bitmap image is stored using a colour depth of 8 bits per pixel. The file is compressed using run-length encoding (RLE). The table shows the compressed and uncompressed values for parts of the image file. Each colour of the pixel in the image is represented by a hexadecimal value. Complete the table. The first row has been completed for you. Uncompressed image RLE compressed image EA F1 F1 F2 F2 F2 EA 1EA 2F1 3F2 1EA 2AB 2FF 11D 167 32 32 80 81 81 RLE is an example of lossless compression. Explain why lossless compression is more appropriate than lossy compression for a text file.
1. Information representation  →  1.3. Compression
1. Information representation  →  1.2. Multimedia Graphics
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10
A Local Area Network (LAN) consists of four computers, one server and a switch. The LAN uses a star topology. Complete the following diagram to show how the hardware is connected. Server Computer Computer Computer Computer Switch A router is attached to one of the devices on the LAN shown in part to connect the LAN to the internet. Identify the device. Give a reason for your choice. Device Reason Describe the role and function of the router in the network.
2. Communication  →  2.1. Networks including the internet
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