The Classroom
Tools, simulators and games
Learn by doing. Everything runs in your browser. Free tools are open to everyone; premium tools open with any unlocked level.
Pseudocode Runner
Write Cambridge pseudocode, run it, and watch a trace table fill in line by line. Perfect for checking your exam answers.
Assembly Simulator
Step through the fetch-decode-execute cycle with a real instruction set. Watch registers and memory change.
Sorting & Searching Visualiser
Bubble, insertion and selection sort, linear and binary search, animated step by step with a running count.
Number System Converter
Binary, denary, hexadecimal and octal with the working shown, plus two's complement.
Logic Lab
Type a Boolean expression, get the full truth table, and try the circuits examiners love.
File Size Calculator
Image, sound and text file sizes from the numbers in the question, with every step and unit.
Cipher Lab
Encrypt and decrypt with a Caesar cipher, break it by trying every key, and see text as binary.
Error Detection Lab
Parity bits, checksums and check digits: flip a bit and see whether it is caught.
Binary Blitz
Convert as many numbers as you can in 60 seconds. Beat your best score and keep your streak alive.
Gate Showdown
A fast quiz on logic gates and truth tables. Build a streak and learn the gates by heart.
Flashcards
Revise key terms card by card. Shuffle, mark what you know and focus on what you do not.