What was done
hivvu and Claude Code disassembled MICRO.EXE and rewrote it routine by routine as a browser game with its own physics, renderer and OPL2 sound sequencer. It reads your own copy of the game data.
hivvu rebuilt Codemasters' Micro Machines (PC, 1994) as a TypeScript program that runs in a browser. The README says he and Claude disassembled the original MICRO.EXE and rewrote it routine by routine, so the page runs the game's own logic, physics and sprite renderer rather than an emulator. It reads the player's own installed copy of the game.
How it was done
Claude Code, using Fable 5.1 and Opus 5 models per the README, read the disassembly, wrote the transliterations and built the capture tooling. A Python transliteration of the physics is checked against ground truth captured by driving DOSBox-X headless, and tests replay those traces. The author decided what to attack next and what counted as proof, and chased cases where a trace diverged at some step. The sound comes from a from-scratch YM3812 (OPL2) written in TypeScript and driven by the game's own sequencer data.
Results
The README lists the Codemasters intro byte for byte, the menus, all 26 Challenge races with the championship, Head to Head for one or two players, all nine rounds and their terrain, music and effects, cheats and keyboard, gamepad and mouse controls. The PC speaker driver is missing. A widescreen option shows more track at several sizes. The code is GPL-3.0 and no game data is included.