Drew Breunig embedded a working NES 6502 CPU emulator into the weights of Qwen3.5-4B, enabling users to run NES ROMs like Super Mario Bros directly inside the model. Inspired by Divyansh Agrawal's qwenputer, the project was built using Claude Opus 5.5 prompts and passes a 15-year-old NES CPU conformance suite.
Background
Building on the trend of embedding hardware emulators into neural network weights, popularized by Divyansh Agrawal's qwenputer project, this work extends the concept to a full NES CPU emulation within an open-weight model.
- Source
- Simon Willison
- Published
- Oct 31, 2026 at 05:59 AM
- Score
- 6.0 / 10