Research NES/Famicom hardware details from NESdev first, with curl and mirror fallbacks, and Mesen implementation only when specs are incomplete.
Use this skill whenever you need details about any part of NES or Famicom hardware. This includes CPU, PPU, APU, DMA, controller ports, cartridge bus behavior, memory maps, timing, electrical quirks, mappers, and console-model differences. Prefer source-backed answers, be thorough, and never guess when the documentation is missing or incomplete.
Define the target precisely before researching.
Start with NESdev as the primary source.
Use this retrieval order when accessing NESdev content.
curl.nes.science mirror, starting from Special_AllPages.xhtml and then opening the relevant .xhtml page.If specification coverage is missing or incomplete, inspect Mesen carefully.
SourMesen/Mesen2 and focus on Core/NES/.When sources disagree or remain ambiguous, report that directly.
Produce a detailed, source-backed answer.
Never guess.
references/source-priority.md: source order, retrieval tips, and Mesen lookup starting points.Researching $4016 / $4017 controller-port behavior:
start with NESdev controller and register pages, then follow links for open bus, expansion-device wiring, and console-model differences.
Researching an APU frame counter detail:
start with NESdev APU and frame-counter pages, then inspect Core/NES/APU/ in Mesen2 only if the written specification leaves a behavior unclear.
Researching a mapper quirk:
start with the mapper page on NESdev, follow board-specific links, then inspect Core/NES/Mappers/ or related mapper factory files in Mesen2 if the written documentation is incomplete.