Developer embeds NES emulator in Qwen3.5-4B weights
What happened
On 31 October 2026, Simon Willison reported that Drew Breunig, inspired by qwenputer, embedded a working NES 6502 CPU emulator in the model weights of Qwen3.5-4B, under the project name dbreunig/nesformer. According to the report, NES ROMs such as Super Mario Bros can now be run inside Qwen, but slowly. Progress remains at the stage where the demo runs with limited speed, and the report does not mention further optimisation or release plans.
Written by AI from the reports · updated 1 h ago
Timeline
Follow the reports to see the event from each side.
- Simon Willisondbreunig/nesformer
dbreunig/nesformer Inspired by qwenputer by Divyansh Agrawal, Drew Breunig baked a working emulator for a Nintendo Entertainment System 6502 CPU into the weights of Qwen3.5-4B. You can now play NES ROMs such as Super Mario Bros (very slowly) running inside Qwen!
Heat of this event
Not enough continuous observations yet to draw a trend.