Understand the machine.
Make something with it.

Why we’re building this

Computers can feel like sealed boxes. We want readers to be able to open them up intellectually: to understand what a variable represents, how a loop runs, why a picture takes memory and what happens between pressing a key and seeing a response.

Vintage machines offer a manageable place to investigate. Their constraints make choices visible. We can follow a small program, examine its data and change something to find out whether our explanation holds.

That understanding gives us more freedom to create. It also helps when we return to modern tools: we can ask what an abstraction does for us, what it costs and when we need to look underneath it.

Learn by making and investigating

We are developing a games development and programming curriculum for children, parents, teachers and anyone curious about computing. You do not need to have owned an old computer, or to know its language before you begin.

Each game grows through guided, runnable stages. We explain the immediate programming and design choices, then connect them to fuller explanations. Small games have a place here: a good puzzle or a single room can give us something worthwhile to build, play and improve.

Foundations explores programming with pseudocode. The Craft brings together game-making ideas, including Maths for Games and Game Feel. System tracks put ideas to work in a particular language and machine. These shared subjects support your chosen route; they are not courses you must finish before making a game.

BASIC and assembly offer different ways in. Spectrum assembly does not require completing Spectrum BASIC. Across the curriculum, we choose languages and projects to suit the machine, and explain what transfers when you try another.

Different machines, different possibilities

The first focus is the ZX Spectrum, Commodore 64, Commodore Amiga and NES. The wider curriculum will explore other computers and consoles through the things they make possible and the choices behind their design.

Original hardware is a useful starting point. Expansions and successor machines can offer further subjects to investigate. When a project needs extra hardware, we will say what it provides and what the original machine still does. Modern development tools do not change the capabilities of the target.

The systems directory distinguishes current lessons from planned coverage. The curriculum is growing; a system page does not mean its teaching material is complete.

Follow the connections

The Vault is our encyclopaedia of computing: machines, games, people and the circumstances in which they worked. The Pattern Library collects practical techniques to adapt to your own projects, with their requirements and trade-offs.

From the Metal examines programming through concrete machine behaviour. Field Notes tells the stories behind our investigations. What’s New records useful additions and changes so you can find what has become available.

Work readers can question

We aim to make claims checkable. Historical accounts need sources; code needs more than a successful build. We distinguish what has been proposed, built or observed running, including the machine or emulator used to check it.

AI assists with development and drafting. Its output needs review and evidence, just as other contributions do. Our Sources & Standards explain the public bar. Corrections and questions help us improve both the material and our understanding.

Who’s behind it

I’m Steve Hill. Early experiences typing programs with my dad and experimenting on a Spectrum left me wanting to make computers do things. That curiosity is why I’m building Code198x.

The lessons are free to read, with original prose licensed underCC BY 4.0. The project is developed in the open. If you know a machine well, can help explain a subject or have worked through a lesson and found a problem, I’d like to hear from you.

Join the discussion, explore ways to contribute, or find a place to start learning.