A2600: Atari VCS core update

I’ve updated the Atari VCS core for the MiST and added F4 bank switching. F4 is the standard Atari scheme for 32kb roms.
Additionally I’ve replaced the 6502 core with the core from Peter Wendrich with his permission. It’s supposed to support illegal opcodes which may help with some previously not working roms.
Unfortunately my test roms (atarsi, bang!, Donkey Kong homebrew) didn’t work properly but the changes won’t harm either 🙂
Grab it from the MiST FPGA Google repository as usual.

8 thoughts on “A2600: Atari VCS core update

  1. Atmosfear says:

    Nice Work! With the new core we have now 66 more Games that are now playable. Overall we have now 335 Games playable and 108 Games Non Playable BUT there are many which start but the Controls are not working. So they are alot of Games which use the Atari Paddle i think, like Atari Circus, Breakout and so on.
    The new core also breaks 5 Games: Indy 500, Skiing, Stampede, Stepplechase and Tennis.
    Thanks again for this Update.

    • WiSo says:

      Thanks for the update! 66 more working vs 5 game broken is okay but not really nice. Wonder why this is because the new cpu core should be more compatible. Are there any documentations about the paddles?

  2. WiSo says:

    Thanks, I’ll have a look later. From a quick glance at link 1 it looks similar to the Apple analog joystick and might be doable.

  3. WiSo says:

    Just a short update. Didn’t had much time to work on it. Stampede works fine for me. Indy 500 works as well but not really steerable. And for Circus there’s a joystick version 🙂

  4. Hi, I’m working on a different Atari core (XL/XE). Peter Wendrich’s 6502 core is what I use too – it is really very accurate, he did a great job. I think I fixes one or two small bugs but nothing major, they are probably in his latest version by now. Paddles are just a variable resistor (500Kohm iirc) and the computer times how long it takes to reach logic high. I guess you know, but Till is going to add support for the 2600daptor. So real ones will be usable.

    I’ve almost got a 5200 core ready. Perhaps we can have an integrated build (as well) which is the 5200 + cx55 😉

    • WiSo says:

      Great work with your Atari core. The paddle implementation is probably similar to what I’ve done for the apple core. I’m short on time these days so till was fine to do it.
      Afaik Peter’s core has also the advantages that it supports “illegal” opcodes which the original 2600 core doesn’t.

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