General Certificate of Secondary Education (GCSE) Computer Science Syllabus

Computer Science syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Computer Science in General Certificate of Secondary Education (GCSE), not a summary of it.

1. 1

   Computer Systems and Architecture

   3 topics

   • The CPU
     • Von Neumann architecture
     • Fetch-decode-execute cycle
     • Registers and factors affecting performance
   • Memory and storage
     • RAM, ROM and virtual memory
     • Secondary storage types
   • Systems software
     • Operating systems
     • Utility software
2. 2

   Data Representation

   4 topics

   • Number systems
     • Binary, denary and hexadecimal conversion
     • Binary arithmetic and shifts
   • Characters and text
     • ASCII and Unicode
   • Images and sound
     • Bitmap images and resolution
     • Sound sampling
   • Data compression
     • Lossy and lossless compression
3. 3

   Networks and Cyber Security

   3 topics

   • Networks
     • LAN, WAN and topologies
     • Protocols and the TCP/IP model
     • The internet and DNS
   • Network security
     • Threats: malware, phishing and social engineering
     • Protection methods and encryption
   • Wired and wireless connectivity
     • Network hardware
     • Wireless standards
4. 4

   Algorithms and Computational Thinking

   3 topics

   • Computational thinking
     • Decomposition and abstraction
     • Algorithmic thinking
   • Searching and sorting
     • Linear and binary search
     • Bubble, merge and insertion sort
   • Algorithm representation
     • Pseudocode and flowcharts
     • Trace tables
5. 5

   Programming and Software Development

   3 topics

   • Programming fundamentals
     • Variables, constants and data types
     • Sequence, selection and iteration
     • Operators and string manipulation
   • Data structures and subprograms
     • Arrays and records
     • Functions and procedures
     • File handling
   • Robust and testable code
     • Validation and authentication
     • Testing and error types
6. 6

   Impacts of Technology

   3 topics

   • Ethical and legal issues
     • Data Protection Act and Computer Misuse Act
     • Copyright and licensing
   • Environmental and cultural impacts
     • Sustainability and e-waste
     • Digital divide and privacy
   • Artificial intelligence and emerging technology
     • Automation and machine learning
     • Societal impact of new technology

Computer Science flashcards for General Certificate of Secondary Education (GCSE)

23 of 89 cards from the Computer Science deck — real questions with worked answers.

1. What are the three main functions of the CPU in the fetch-decode-execute cycle?

   Fetch the next instruction from memory, decode it (work out what it means), and execute it (carry out the instruction). The cycle then repeats.

2. What is the purpose of the Program Counter (PC) in the CPU?

   It holds the memory address of the next instruction to be fetched. It is incremented after each fetch (or changed by a jump instruction).

3. What does the Memory Address Register (MAR) hold, and what does the Memory Data Register (MDR) hold?

   The MAR holds the address of the memory location being read from or written to. The MDR holds the data or instruction that has just been fetched from, or is about to be written to, that location.

4. What is the role of the Accumulator (ACC) in the CPU?

   It is a register inside the ALU that temporarily stores the results of calculations and logical operations.

5. Name three factors that affect CPU performance.

   Clock speed (number of cycles per second), number of cores, and cache size.

6. State the three characteristics of Von Neumann architecture relevant to the CPU.

   Both data and instructions are stored in the same memory, instructions are processed sequentially, and the CPU uses registers (PC, MAR, MDR, ACC, CIR) to manage the fetch-decode-execute cycle.

7. What is the purpose of cache memory, and why is it faster than RAM?

   Cache stores frequently used instructions and data close to the CPU so they can be accessed quickly. It is faster because it is smaller and physically closer to (or on) the CPU than main memory (RAM).

8. What is the key difference between RAM and ROM?

   RAM is volatile (loses contents when power is off) and can be read from and written to. ROM is non-volatile (keeps contents without power) and is read-only, typically storing the boot/startup instructions.

9. What is virtual memory and when is it used?

   Virtual memory is a portion of secondary storage (the hard disk) used as if it were RAM when RAM is full. Data is moved between RAM and the disk to free up space, though this is slower.

10. Compare the three main categories of secondary storage: magnetic, optical, and solid state.

    Magnetic (e.g. HDD) uses magnetised platters - high capacity, cheap, but has moving parts. Optical (e.g. CD/DVD) uses pits/lands read by laser - low capacity, portable. Solid state (e.g. SSD/USB) uses flash memory - fast, no moving parts, durable, but more expensive per GB.

11. Give three characteristics used to evaluate a storage device.

    Capacity (how much it can store), speed (read/write rate), and durability/portability/cost per gigabyte.

12. What is the difference between system software and application software?

    System software manages the computer and provides a platform for other programs (e.g. operating system, utilities). Application software lets the user perform specific tasks (e.g. word processor, browser).

13. List five functions of an operating system.

    Memory management, process/CPU management, peripheral and device management (via drivers), file management, and user interface provision (plus user/account management and security).

14. What is the role of a device driver?

    It is software that allows the operating system to communicate with and control a specific hardware device (e.g. printer, graphics card).

15. Name three examples of utility system software.

    Encryption software, defragmentation software, and data compression/backup software.

16. Why does defragmentation software improve performance on a magnetic hard disk?

    It reorganises fragmented files so the parts of each file are stored contiguously, reducing the read/write head movement needed to access them and speeding up access.

17. Convert the binary number $1011\,0110_2$ to denary.

    $128 + 32 + 16 + 4 + 2 = 182$, so $1011\,0110_2 = 182_{10}$.

18. Convert the denary number $217$ to an 8-bit binary number.

    $217 = 128 + 64 + 16 + 8 + 1$, giving $1101\,1001_2$.

19. Convert the hexadecimal number $\text{2F}_{16}$ to denary.

    $2 \times 16 + 15 = 32 + 15 = 47$, so $\text{2F}_{16} = 47_{10}$.

20. Why is hexadecimal commonly used in computing instead of binary?

    It is more compact and easier for humans to read and write - one hex digit represents exactly 4 bits (a nibble), so long binary numbers become much shorter and less error-prone.

21. What is the result of the binary addition $0101\,1100_2 + 0011\,0101_2$ in 8 bits?

    $1001\,0001_2$ (which is $92 + 53 = 145$ in denary).

22. What happens, and what is the term, when a binary addition produces a result too large for the available number of bits?

    An overflow occurs - the carry out of the most significant bit is lost, giving an incorrect result. The condition is called overflow.

23. Performing a binary shift left by 2 places on an unsigned number has what arithmetic effect?

    It multiplies the number by $2^{2} = 4$. Each left shift multiplies by 2; vacated positions are filled with 0s.

See more Computer Science flashcards →

Planning Computer Science for General Certificate of Secondary Education (GCSE)

Computer Science (General Certificate of Secondary Education (GCSE)) FAQ