AQA GCSE Computer Science

Revision topics

One topic at a time: what the specification asks for, what it doesn’t, worked examples, and the mistakes that cost marks. Free to read, no account needed.

Revision Checklist →Every spec point as an “I can…” statement to tick off.Character Encoding →Interactive 7-bit ASCII table, Bit-5 case switcher (±32), sequential alphabet offsets, and Unicode explorer.Representing Images →Interactive pixel canvas, binary & hex scanline decoder, and broken metadata simulator.Representing Sound →Interactive sound wave sampling, quantisation visualizer, Web Audio synthesis, and ADC/DAC challenges.Hex & Nibbles →Interactive 8-bit binary to hex nibble-splitter and base-16 converter.Two’s Complement →Interactive 8-bit signed converter with place-value breakdown (-128 to +127).Binary Shifts →Interactive logical left (×2ⁿ) and right (÷2ⁿ) shift visualizer with overflow warnings.Binary Addition →Interactive column addition visualizer for 2 or 3 binary numbers with register overflow detection.File Size Calculator →Interactive image and sound file size calculator with exam working.Python & SQL Cheat Sheet →Printable desk reference for AQA Paper 2: built-ins, string slicing, 2D arrays, and SQL queries.Top 20 Exam Trapdoors →Examiner report analysis of the 20 most frequent mistakes where students lose 15+ marks.Grade Boundaries →Official AQA 8525 grade thresholds & mock exam predictor.

Data Representation

Computational Thinking

Computer Systems

More topics are added as each video lesson is released. See everything the course covers →