Courses
Every course is free and open. Filter by stage, or follow the map from the first switch to the processor.
Inside the Machine
A computer only knows two things: on and off. Everything else is built from them.
Giving Instructions
A computer does exactly what it is told. Learn to tell it exactly.
The Secret Code of Computers
Numbers, letters and emoji: everything becomes 0s and 1s.
Logic: Machines that Decide
Three tiny rules, AND, OR and NOT, are enough to build a calculator.
The Transistor: the Switch that Changed Everything
Open the most manufactured object in history and see how it really works.
Your First Programs
Four ideas, variables, decisions, loops and functions, are behind every program ever written.
How a CPU Works
Fetch, decode, execute: three steps, repeated billions of times a second.
From Code to Machine
Follow one line of Python all the way down to moving electrons.
Algorithms: Thinking Fast
A better idea beats a faster computer.
The Limits of Computation
What no program can ever do, and how small a switch can get.
How Programs Really Run
The call stack and floating-point numbers: two things every expert must see clearly.
The Story of Computing
Twelve centuries from the first algorithm to a computer in every pocket.