Explore How Computers
Actually Work

Hands-on interactive tools and sandboxes to understand binary, data representation, algorithms, and computer systems for GCSE.

AQA GCSE (8525)

Searching & Sorting

Master Binary and Linear search, step through Bubble, Insertion, and Merge sort, compare efficiency side-by-side in race mode, and practice pass-by-pass tracing.

  • ✓ Linear Search (O(n)) & Binary Search (O(log n)) with interactive Low, Mid, High pointers and search-space halving
  • ✓ Step-by-step sorting animations with comparisons, swaps, and intuitive explanations
  • ✓ Algorithm race modes comparing best, average, and worst-case time complexities
Paper 1 Algorithms 3.1 Binary • Linear • Bubble • Merge AQA Core ★

Interactive Trace Table Lab

Master the guaranteed 4–6 mark Paper 1 exam question. Step through loops and conditions line-by-line while filling the trace grid.

  • ✓ Step-by-step code execution pointer synchronized with live variable inspector
  • ✓ Interactive exam trace table: fill cells and get instant mark-scheme feedback
  • ✓ Classic AQA traps: off-by-one loop bounds, integer division, and boolean logic
Paper 1 Design & Testing 3.2 Loops & Logic Guaranteed Exam Q

Numbers & Characters

Interactive 8-bit binary register, two's complement, binary arithmetic, bitwise logic (AND, OR, XOR), shifts, data units, and ASCII/Unicode text encoding.

  • ✓ 8-bit interactive register, +/-1 steppers, and 3-way Denary/Hex/Binary live converter
  • ✓ Addition with overflow alert, two's complement subtraction workbench, and bitwise logic masks
  • ✓ Data units scale (kB vs KiB) and live secret message character encoder
Paper 2 Numbers 3.3.1 Characters 3.3.2 AQA 8525 §3.3

Media Representation

Draw on a pixel grid to see bitmap binary, test sound sampling & quantization with a live musical Theremin, record your voice, and explore RLE compression.

  • ✓ Interactive drawing grid & large photo quantization (1-bit up to 24-bit True Colour)
  • ✓ Sound Theremin and 2.0s voice recorder demonstrating sampling rate and bit depth
  • ✓ Image & audio file size calculations with dual prefix breakdown (kB vs KiB) and RLE run tracker
Paper 2 Bitmaps 3.3.3 Sound 3.3.4 AQA 8525 §3.3

CPU Architecture & FDE Cycle

Step through the Von Neumann Fetch-Decode-Execute cycle, watch animated data-packets travel between registers, and benchmark CPU clock speed, cache, and cores.

  • ✓ Animated register data-flow: PC, MAR, MDR, ACC, CU, and ALU across Address, Data & Control buses
  • ✓ Step-by-step FDE stage tracer with clear AQA mark-scheme explanations
  • ✓ CPU Performance Sandbox: Clock Speed (GHz), Cache size (L1/L2), and Multi-Core bottlenecks
Paper 2 Hardware 3.4.1 Von Neumann Registers AQA 8525 §3.4

Relational Databases & SQL

Interactive SQL Studio with live clause tracer (FROM → WHERE → ORDER BY → SELECT), visual Primary/Foreign key schema, and exam practice challenges.

  • ✓ Interactive SQL engine testing the 4 AQA commands: SELECT, FROM, WHERE, ORDER BY
  • ✓ Linked two-table schema with Primary Key (PK) & Foreign Key (FK) relationship explorer
  • ✓ Warm-up to exam-level challenges with instant automated mark schemes & model answers
Paper 2 Databases 3.7 SQL Queries AQA 8525 §3.7