Edexcel GCSE Computer Science revision

Topic 1: Computational thinking

There are 7 parts: we start with computational thinking and algorithms, and finish with Boolean logic.

1. 1.1Computational thinking and algorithmsFree 31 questions
2. 1.2Writing algorithms in pseudocode and flowcharts (exam reference languages)Free 20 questions
3. 1.3Trace tables, dry-running and finding errors in algorithms26 questions
4. 1.4Searching algorithms: linear and binary search62 questions
5. 1.5Sorting algorithms: bubble, insertion and merge sort31 questions
6. 1.6Comparing the efficiency of algorithms23 questions
7. 1.7Boolean logic: AND, OR, NOT, XOR gates, truth tables, logic diagrams and expressions58 questions

Topic 2: Data

There are 6 parts: we start with binary, hexadecimal and units, and finish with compression in practice.

1. 2.1Binary, hexadecimal and unitsFree 70 questions
2. 2.2Binary addition and binary shiftsFree 69 questions
3. 2.3Representing negative numbers: sign and magnitude, two's complement61 questions
4. 2.4Text, images, sound and compression72 questions
5. 2.5Calculating file sizes for text, images and sound, and converting units66 questions
6. 2.6Compression in practice: run-length encoding and Huffman coding68 questions

Topic 3: Computers

There are 9 parts: we start with hardware, the CPU and memory, and finish with programming languages and IDE tools (editors, error diagnostics, debuggers, run-time environment).

1. 3.1Hardware, the CPU and memoryFree 44 questions
2. 3.2Von Neumann architecture and the fetch-decode-execute cycle with registersFree 29 questions
3. 3.3Factors affecting CPU performance: clock speed, cores and cache31 questions
4. 3.4Primary memory: RAM, ROM and virtual memory41 questions
5. 3.5Secondary storage: magnetic, optical and solid state, and choosing storage74 questions
6. 3.6Embedded systems and input/output devicesFree 27 questions
7. 3.7Operating systems and utility software33 questions
8. 3.8Software, translators and logic28 questions
9. 3.9Programming languages and IDE tools (editors, error diagnostics, debuggers, run-time environment)32 questions

Topic 4: Networks

There are 7 parts: we start with networks and protocols, and finish with firewalls, anti-malware, access levels and penetration testing.

1. 4.1Networks and protocolsFree 65 questions
2. 4.2Network types (LAN, WAN, PAN) and topologies (star, bus, mesh)Free 65 questions
3. 4.3Network hardware and transmission media: wired, Wi-Fi and Bluetooth69 questions
4. 4.4Protocols and the TCP/IP layers: HTTP, HTTPS, FTP, SMTP, IMAP, POP34 questions
5. 4.5IP and MAC addresses, DNS and packet switching37 questions
6. 4.6Client-server, peer-to-peer, the cloud and virtual networks82 questions
7. 4.7Firewalls, anti-malware, access levels and penetration testing39 questions

Topic 5: Issues and impact

There are 9 parts: we start with environmental impacts, and finish with protecting systems.

1. 5.1Environmental impacts: energy use, e-waste and sustainable technology32 questions
2. 5.2Ethical, legal and environmental impacts16 questions
3. 5.3UK legislation: Data Protection Act 2018, Computer Misuse Act 1990, Copyright, Designs and Patents Act 198830 questions
4. 5.4Software licensing: open source and proprietary33 questions
5. 5.5Case studies: privacy and surveillance, AI and bias, autonomous vehicles, the digital divide39 questions
6. 5.6Cyber security26 questions
7. 5.7Social engineering: phishing, pharming, blagging and shoulderingFree 37 questions
8. 5.8Malware and network attacks: brute force, denial of service, SQL injection, data interception79 questions
9. 5.9Protecting systems: strong passwords, biometrics, two-factor authentication and encryption29 questions

Topic 6: Problem solving with programming

There are 10 parts: we start with programming fundamentals, and finish with evaluating solutions and exam technique for code and extended-response questions.

1. 6.1Programming fundamentals27 questions
2. 6.2Arrays (1D and 2D) and recordsFree 26 questions
3. 6.3String manipulation, random numbers and file handling27 questions
4. 6.4Subroutines: functions, procedures, parameters and local/global scope26 questions
5. 6.5Defensive design: input validation, sanitisation, authentication and maintainable code33 questions
6. 6.6Syntax, logic and runtime errors, and designing test plans (normal, boundary, invalid, erroneous data)35 questions
7. 6.7Translating a specification into a working programFree 31 questions
8. 6.8Debugging and tracing unfamiliar programs30 questions
9. 6.9Implementing searching and sorting algorithms in code25 questions
10. 6.10Evaluating solutions and exam technique for code and extended-response questions17 questions

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