Ask API. GET https://whichemulator.wtf/ask answers questions from the same data as this page, and it is the only place the setup steps are published. It takes the question as q and, optionally, this page's path as page, and returns JSON with answer, sources and follow_ups, or Markdown with Accept: text/markdown. No key needed.
curl -G 'https://whichemulator.wtf/ask' --data-urlencode 'q=How do I set up Stella for the Atari 2600?' --data-urlencode 'page=/atari2600/'Questions it answers:
Guide: /skill.md. This page as Markdown: /atari2600.md
Atari Video Computer System, Atari, 1977. Atari VCS.
whichemulator.wtf calls its recommendation for each system the Gold Cartridge pick. For the Atari 2600, the Gold Cartridge pick is Stella.
Stella has been the answer for the 2600 for over twenty years, and it is still maintained. It is cycle-exact, handles every odd bankswitching scheme and controller, and has a debugger homebrew developers rely on. Nothing else comes close for everyday play.
Runs on Windows · Mac · Linux. Open source. Download: https://stella-emu.github.io
No BIOS needed.
The 2600 has no frame buffer, so games draw the picture line by line while the beam moves. That makes timing everything, and Stella gets it right. It also knows about paddles, keypads, driving controllers and the Supercharger, so the strange corners of the library work too.
It is still the emulator the homebrew scene tests against, which is why new 2600 games tend to work in it first.
Setup steps for Stella are published only by the Ask API: How do I set up Stella for the Atari 2600?
Reference: WEM-ATARI2600-5XXA