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Code Quest

From the transistor to the program.

The map

A computer is built in layers: switches, gates, circuits, a processor, programs. Follow the stages in order; every course shows its lessons and your progress.

Set your level to get a personal starting point.

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Sparks1-bitBuilders4-bitCoders8-bitEngineers32-bitArchitects64-bit

Each stage is a wider word: from 1 bit, a single switch, to the 64 bits of a modern processor.

  1. 1
    Stage 1 · 1-bit

    Sparks · Ages 7–10 · first steps

    On and off, pictures made of switches, and giving a robot exact instructions.

    🔌Inside the MachineA computer only knows two things: on and off. Everything else is built from them.
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    🤖Giving InstructionsA computer does exactly what it is told. Learn to tell it exactly.
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  2. 2
    Stage 2 · 4-bit

    Builders · Ages 10–13

    Counting in binary, letters as numbers, logic gates and a circuit that adds.

    🔢The Secret Code of ComputersNumbers, letters and emoji: everything becomes 0s and 1s.
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    🚦Logic: Machines that DecideThree tiny rules, AND, OR and NOT, are enough to build a calculator.
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  3. 3
    Stage 3 · 8-bit

    Coders · Ages 13–16

    How a transistor works, gates made of transistors, memory, and your first real programs.

    ⚛️The Transistor: the Switch that Changed EverythingOpen the most manufactured object in history and see how it really works.
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    0/3 lessonsStart
    🐍Your First ProgramsFour ideas, variables, decisions, loops and functions, are behind every program ever written.
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  4. 4
    Stage 4 · 32-bit

    Engineers · Ages 16–18

    Inside the processor, machine code, compilers, searching, sorting and big O.

    🧠How a CPU WorksFetch, decode, execute: three steps, repeated billions of times a second.
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    🪜From Code to MachineFollow one line of Python all the way down to moving electrons.
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    ⏱️Algorithms: Thinking FastA better idea beats a faster computer.
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  5. 5
    Stage 5 · 64-bit

    Architects · Ages 18+ · advanced

    Turing machines, the limits of chips, the call stack and floating-point numbers.

    ♾️The Limits of ComputationWhat no program can ever do, and how small a switch can get.
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    🧬How Programs Really RunThe call stack and floating-point numbers: two things every expert must see clearly.
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A side quest for everyone

For everyone

The story of computing and the people who invented it.

📜The Story of ComputingTwelve centuries from the first algorithm to a computer in every pocket.
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⏳Read the history