Why the UNC exists

I write software with AI agents all day (mostly Claude Code). I'm good at it and I like it.

But I miss something. The UNC 64 is my attempt to get it back.

When I was a kid, a computer was a thing you could understand completely. The manual told you where everything lived. If you were patient you could hold the whole machine in your head: every byte of memory, every instruction, every trick someone printed in a magazine.

Nobody holds a modern system in their head. I sure as hell don't hold mine.

That's fine for work. For fun, I want the other thing.

So I'm building a computer.

It's called the UNC 64, made by United Northern Computers, a company that never existed. It's a fantasy 8-bit machine in the spirit of the Commodore 64, the ZX Spectrum and the Apple II (my own was an Amiga 500, inherited from my uncle. Yes, that's where the story comes from). It's emulated for real. Everything on its screen is computed by a CPU I'm designing.

What's the game?

You, a modern-day software engineer, inherit your uncle's old computer. You switch it on and wake up in 1984, at the same desk.

There's a monthly computer magazine, a tape deck, a ring binder full of the uncle's notes and a lot of programs to write. Sixteen of them carry the story.

What's decided?

• A fantasy CPU in the 6502 family. About 35 instructions, a fast page and a fixed cycle table you can count on.
• You start on a UNC 16: 16K of memory, a green monochrome screen, a beeper and a tape deck. You earn your way to the full 64K, one upgrade at a time.
• Integer BASIC in ROM and a line editor like the one on the C64. No filesystem. Programs live on tape.
• Puzzles are checked against a spec and scored in cycles. Leaderboards from day one.
• No deadlines and no fail states. Sleep, and the next issue of the magazine arrives.

Built with AI? Yes. All of it.

Let's be upfront about this: the whole thing is built with AI assistance. The emulator, the BASIC, the assembler, the manual and the game.

I already know how to program games. Learning that again is not why I'm here.

The point is to relive the feeling of exploring and learning an 8-bit computer from the 6502 family. That, plus making the design decisions: what the CPU does, what the manual says, what the machine is allowed to be.

The agents type. I decide.

Why a devlog?

This project is how I'm relearning computers from the bottom up.

I've read Petzold's Code, worked through Easy 6502, played a lot of PICO-8 and watched more Ben Eater than is healthy. Next up: the CPU core in Rust, with a test for every instruction.

These memos are where I write down what I learn. There's no release date. I'm building this on evenings and weekends and it takes as long as it takes.

Let's see how far this goes! 🚀

Viljami