Level:
Correct: 0
Incorrect: 0
Marks: 0/0
Exam Practice
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Cambridge IGCSE Computer Science (Paper 1) Smart practice A mixed round aimed at your weak spots
Unit 1
Data representation
Number systems
Binary, denary and hexadecimal conversions
0%
Uses of hexadecimal
0%
Binary addition and overflow
0%
Logical binary shifts
0%
Two's complement
0%
Text, sound and images
Character sets: ASCII and Unicode
0%
Representing sound
0%
Representing images
0%
Data storage and compression
Data storage units and file size calculations
0%
Data compression
0%
Unit 2
Data transmission
Types and methods of data transmission
Packets and packet switching
0%
Methods of data transmission
0%
The USB interface
0%
Methods of error detection
Parity, checksum and echo check
0%
Check digits and ARQ
0%
Encryption
Encryption
0%
Unit 3
Hardware
Computer architecture
The CPU, Von Neumann architecture and the FDE cycle
0%
Cores, cache and clock speed
0%
Instruction sets and embedded systems
0%
Input and output devices
Input devices
0%
Output devices
0%
Sensors
0%
Data storage
Primary storage: RAM and ROM
0%
Secondary storage: magnetic, optical and solid-state
0%
Virtual memory and cloud storage
0%
Network hardware
Network hardware: NIC, MAC and IP addresses, routers
0%
Unit 4
Software
Types of software and interrupts
System software, application software and operating systems
0%
Firmware and interrupts
0%
Programming languages, translators and IDEs
High-level languages, low-level languages and assembly language
0%
Compilers and interpreters
0%
Integrated development environments (IDEs)
0%
Unit 5
The internet and its uses
The internet and the world wide web
The internet, the world wide web, URLs and HTTP(S)
0%
Web browsers, locating web pages and cookies
0%
Digital currency
Digital currency and blockchain
0%
Cyber security
Cyber security threats
0%
Keeping data safe: security solutions
0%
Unit 6
Automated and emerging technologies
Automated systems
Automated systems
0%
Robotics
Robotics
0%
Artificial intelligence
Artificial intelligence
0%
Avg
score:
–
Topics
done:
0/39

Firmware and interrupts

Practise 29 exam-style questions on Firmware and interrupts for Cambridge IGCSE Computer Science (Paper 1). Write your answer as you would in the exam and get it marked in seconds against the mark scheme, point by point, with an AI tutor on hand if you get stuck.

  • 29 questions
  • 1–6 marks each
  • Instant marking
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20 questions, marked as you go

Sample questions with model answers

Here are 4 of the questions in this topic, each with a model answer, an explanation of why it earns the marks and the mark scheme an examiner would use.

Question 1

1 mark

State when the processor checks whether an interrupt has been received.

Model answer

At the end of each fetch-decode-execute cycle.

Explanation

The processor finishes the instruction it is working on and then checks for interrupts before starting the next cycle. This way no instruction is left half done when the processor switches to the interrupt service routine.

Mark scheme
  1. 1 mark

    At the end of each fetch-decode-execute cycle

    accept at the start of each FDE cycle / between instructions; do not accept 'all the time' or 'when it is idle'

Question 2

2 marks

Describe the role of the bootloader when a computer is switched on.

Model answer

The bootloader is firmware that runs on the hardware as soon as the computer is switched on. It loads the operating system from secondary storage into RAM and then hands control over to the operating system.

Explanation

The operating system is stored on a hard disk or SSD, and RAM is empty at switch-on. The bootloader, kept in ROM, bridges that gap by loading the operating system, which is why the OS is said to run on the firmware.

Mark scheme
  1. 1 mark

    It is the first program to run (on the hardware) when the computer is switched on

    max 2

  2. 1 mark

    It loads the operating system from secondary storage into RAM

    accept 'starts the operating system'

  3. 1 mark

    It then passes control to the operating system

  4. 1 mark

    It may check that the hardware is working (POST)

Question 3

3 marks

A printer runs out of paper while it is printing a document.

Describe how an interrupt is generated and what happens as a result.

Model answer

The printer generates a hardware interrupt by sending a signal to the processor. The processor saves its current task and runs the interrupt service routine, which displays a message asking the user to add more paper. Printing is paused until paper is loaded, and the processor returns to its other tasks.

Explanation

Describe both halves: how the interrupt is generated (the device sends a signal to the processor) and what happens as a result (the ISR alerts the user and the processor carries on). This is a hardware interrupt because a device caused it.

Mark scheme
  1. 1 mark

    The printer sends an interrupt signal to the processor (a hardware interrupt)

    max 3

  2. 1 mark

    The processor saves its current task and runs the interrupt service routine

  3. 1 mark

    A message is displayed telling the user to add paper

  4. 1 mark

    Printing is paused until paper is added, while the processor carries on with other tasks

  5. 1 mark

    When paper is added, printing continues

Question 4

4 marks

Describe two differences between firmware and an operating system.

Model answer

Firmware is stored in ROM on the hardware itself, whereas the operating system is stored on secondary storage and loaded into RAM. Also, the firmware (bootloader) runs directly on the hardware and starts the computer, whereas the operating system runs on the firmware and manages the whole system and the applications.

Explanation

A difference needs both sides: what firmware is like and what the operating system is like. The syllabus layering gives an easy one: the bootloader runs on the hardware, but the operating system runs on the firmware.

Mark scheme
  1. 1 mark

    Firmware is stored in ROM / flash memory on the hardware

    max 4: two differences, each needing both sides for 2 marks

  2. 1 mark

    whereas the operating system is stored on secondary storage (HDD / SSD) and loaded into RAM

  3. 1 mark

    Firmware (the bootloader) runs directly on the hardware

  4. 1 mark

    whereas the operating system runs on the firmware

  5. 1 mark

    Firmware provides low-level control of the hardware / starts the computer

  6. 1 mark

    whereas the operating system manages the whole system, e.g. files, memory, the interface, and runs applications

  7. 1 mark

    Firmware is rarely changed / not normally changed by the user

  8. 1 mark

    whereas the operating system is updated regularly / can be changed or replaced by the user

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