# dbreunig/nesformer

- Source: Simon Willison (LLMs)
- Published: 2026-10-30T21:59:22+00:00
- Category: Tech
- Original: https://simonwillison.net/2026/Oct/30/nesformer/
- Canonical: https://groundlevelnews.com/story/dbreunig-nesformer-1649c5/

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! In a comment on Hacker News Drew reveals the Opus 5.5 prompts he used to build this system: Read this article and any relevant source cod

_Ground Level News shows a short summary only; the full article and all rights belong to Simon Willison (LLMs)._