30 October 2026
Developer embeds a working NES CPU emulator inside Qwen model weights
First reported
Simon Willison ran this on .
- Drew Breunig built a NES 6502 processor emulator directly into the weights of Qwen3.5-4B, a small open AI model from Alibaba.
- The result lets the model run classic NES game files such as Super Mario Bros, though it runs very slowly.
- It is a playful proof of concept, following an earlier project of the same kind, and the author published the prompts he used to build it.
How it was covered
Simon WillisonDaily notes and links
The Qwen-based NES emulator project, its inspiration, the Hacker News comment with Opus prompts, and a proposed follow-up on FPGA-style chip emulation