Rebuild an old game's source code with AI models
A developer used OpenAI, Anthropic and Google models to reconstruct Civilization 1's source; it builds with 1991-era tools into a byte-for-byte match, apart from a four-byte fix.
Done with Other
What they did
A developer directed AI models from OpenAI, Anthropic and Google to turn the 1991 Civilization program back into readable C code. He pointed them at an earlier project, OpenCiv1, then edited the output. He built it with the original-era Microsoft compiler in an emulator and checked the result against the real game file. The AI also helped write a technical book about the game.
How it went
He reports the rebuilt program matches the original byte for byte, except a four-byte fix for a likely post-build patch. He also used the code to make a modern version of the game.
Worth knowing
The author credits OpenCiv1 with most of the work and warns the names and comments are guesses, so a matching program does not prove this is the original source.
Try it yourself
Help me reconstruct readable source code for [old program name and version]. Use [existing reverse-engineering project or notes] as a starting point. Work one function at a time: write the code, build it with [period compiler/toolchain], and compare the output with the original file. Keep a log of which parts match and which don't. Show me your plan first and pause after each batch of functions for my review.
Swap the highlighted [parts] for your own details.
Source: Hacker News · crc32 (sjmelia) · Oct 20, 2026
Written with AI assistance from the original post and checked against our editorial guidelines. Results are as reported by the source, not independently verified. Spotted a mistake? Tell us.
