The main twist: I decided to see how far I could get using Claude Code for the firmware. That and the web emulator were written almost entirely using Claude Code (Opus 4.5). I've kept the full prompt history here: https://github.com/gzalo/microcomputer/blob/main/ai_prompts....
It was able to create the emulator in just a few prompts! It really surprised me that it was able to make a WebAssembly version from the same code (compiled with emscripten) and get the physical layout of the panel from a given photo. It also created some simple working examples using 8086 instructions!
Repository: https://github.com/gzalo/microcomputer