What is Insert Coin.
Insert Coin is a diagnostic chat for pinball and arcade machine repair. You paste in a symptom like “left flipper feels weak”, “STTNG resets when I drop the ball”, “Galaga blank at boot”, and get a step-by-step diagnosis grounded in the actual operations manual for that title, with citations.
Pinball and arcade repair is a closed domain with decent public manuals, deeply specific questions, and a community that already knows the answers. Insert Coin isn't here to displace forum experts. It's here to make the answers they've already given easier to find.
Think of this less like a finished product and more like an open lab notebook. Things move, and answer quality is improving but uneven. The honest assessment of where it stands is on the pricing page. The same architecture extends to any machine with a manual: jukeboxes, synths, appliances, test gear. Arcade is chapter one.
How answers are built
1. Ingest. Operations manual PDFs are OCR'd, layout-parsed, and split into page-bounded, heading-aware chunks. Each chunk is embedded and stored in a vector database.
2. Retrieve. Your question gets embedded too. We pull the closest chunks by cosine similarity, scoped to the machine you tagged with #code.
3. Answer. The retrieved sections are handed to the language model as grounding context. It writes a step-by-step plan and cites the manual sections it leaned on.
4. Learn. When you bless an answer, it becomes a verified prior that surfaces on similar future questions. Decades of public Usenet archives get distilled into the same shape. We don't scrape Pinside, KLOV, or any private forum, only public archives published for preservation.