Instructions:
- Answer all questions. Write your answers in the spaces provided.
- The number of marks available is shown in brackets for each question.
- For extended writing questions, quality of explanation and use of technical vocabulary will be considered.
- Suggested time: 50 minutes.
Section A - Short answer (20 marks)
1 Registers[4 marks]
Complete the table. Write the correct register name or its purpose.
| Register | Purpose |
|---|
| Stores the address of the next instruction to be fetched from memory. |
| Memory Data Register (MDR) | |
| Accumulator (ACC) | |
| Stores the address of the memory location currently being accessed. |
2 FDE Cycle[3 marks]
Describe what happens during the fetch-decode-execute cycle. Give three distinct points.
3 CPU Components[1 mark]
State the purpose of the CPU.
4 True / False[5 marks]
Tick (✓) one box in each row to show whether each statement is True or False.
| Statement | True | False |
|---|
| The ALU performs arithmetic calculations and logical comparisons. | | |
| RAM is non-volatile and retains data when the power is off. | | |
| In Von Neumann architecture, programs and data share the same memory. | | |
| An SSD uses spinning magnetic platters to store data. | | |
| Cache stores frequently used instructions closer to the CPU than RAM. | | |
5 CPU Performance[3 marks]
Give three characteristics of a CPU that can affect its performance.
6 Storage[4 marks]
Describe two differences between RAM and ROM.
Section B - Apply (14 marks)
7 Clock Speed[3 marks]
The specification of two computers is shown below.
Computer A: Clock speed 3.6 GHz, 4 cores, 6 MB cache
Computer B: Clock speed 1.8 GHz, 4 cores, 6 MB cache
(a) Explain why Computer A is likely to run programs faster than Computer B.[2 marks]
(b) State what is meant by a clock speed of 3.6 GHz.[1 mark]
8 Multi-core & Cache[4 marks]
(a) Explain how cache memory improves the performance of the CPU.[2 marks]
(b) Explain how a dual-core processor can improve performance compared to a single-core processor.[2 marks]
9 Virtual Memory & Storage[4 marks]
Riya uses her computer for video editing. She often has several large applications open at the same time and finds her computer slows down significantly.
(a) Explain what virtual memory is and why it is causing Riya's computer to slow down.[2 marks]
(b) Riya is considering replacing her HDD with an SSD. Give two reasons why this could improve performance for video editing.[2 marks]
10 Storage & Registers[3 marks]
A student says: "The Program Counter is the part of the CPU that counts how many programs the computer has run."
State whether this is correct or incorrect and explain what the Program Counter actually does.
Section C - Extended writing (6 marks)
11 Extended Writing[6 marks]
A school is replacing its ageing computers. The IT manager wants to choose upgrades that will give the biggest improvement in performance for students running programming software and watching video content.
Identify at least three possible upgrades and explain how each would improve performance. In your answer, use correct technical vocabulary and clearly link each upgrade to its effect on the computer's performance.