minimig AGA v1.2 for the MiST board released

There is a new release of minimig-AGA for the MiST board available, grab it on the minimig-mist page!

While the CPU is still not as stable as I’d like, the latest bitfield fixes by Till Harbaum fixed a lot of games and demos that didn’t work properly before. The OSD Turbo option is not needed or recommended for games or demos anymore, but could still be used for a little speed up in Workbench or programs. F11 key was fixed – when HRTmon is enabled, the F11 key enters the monitor program, when it is disabled, the F11 key acts as a normal Amiga HELP key. There is a CD32Pad option in the OSD, but I didn’t have time to fix the CD32 joypad emulation, so the option doesn’t have any effect for now. Initial support for programmable display modes (productivity modes, like 640x480x60Hz) is available in this core, but there are still some problems with them – some pixels are missing on the right edge of screen, and lowres sprites (mouse pointer) seem to have some problems – You can switch to hires pointer to get around this problem.

The planned ethernet support will unfortunately have to wait till the next release.

Please report any bugs or problems here: (if you have a Github account)
– or – (no account needed)

Here are all of the updates made in this release:

  • initial implementation of programmable display modes
  • OSD HRTmon enable / disable switch is working (ON – F11 acts as NMI and enters HRTmon, OFF – F11 is HELP key)
  • proper handling of CPU access to chipRAM & custom regs – CPU waits for free slot when turbo option is disabled
  • fixed playfield 2 color lut offset when playfield 2 has priority for OCS/ECS modes
  • some IRQ changes
  • added support for undocumented Agnus / Denise behaviour when BPL=7 in ECS/OCS mode (fixes demos like SushiBoyz by Ghostown, Sliced&Diced by Dekadence, etc)
  • blitter line mode fixed (fixes demos like SushiBoyz & Sunglasses by Ghostown, Vectorize by RSi, etc)
  • bitfield instructions fixed, barrel shifter implemented by Till Harbaum
  • fixed colortable for sprites (bplxor) – fixes Alien Breed 3D (and probably many others)
  • fixed keyboard rate
  • kickstart ROM is also uploaded to mirror position (E0)
  • fixed reset problems & fastRAM disappearing
  • added CPU CACR cache control, fixed reading CACR reg
  • added scanlines for non-doublescaned config
  • fixed video dithering – both spatial & random dithering weren’t working properly


13 thoughts on “minimig AGA v1.2 for the MiST board released

  1. Juri says:

    Ahhh that’s a great new! Finally games like the Mercenary saga are playable 😀
    is it possible to remap the HELP/HRTMON key to PAGEDOWN key?
    just to have the same keyboard configuration in mist & winuae ,maybe in the mist.ini file

    • Juri says:

      thank you it perfectly worked.
      oh btw, i do not know if it’s a bug or my samsung but i experienced a strange behaviour:
      try to load the game FRONTIER and watch the intro with scan lines enabled (black for better effect)
      the image is very shaky and sometime it look like an avi with high compression.
      could someone check it?

  2. Fenio says:

    DoomAttack works grat on Minimig v1.2 🙂
    My video with loading and gameplay
    If you want can be used to “user videos” on MiST Wiki.
    Free advertisement in youtube video description 🙂 Good things worth promoting.

  3. Hi!

    What about a new version of the Amiga AGA Core for MiST MPGA. Your currently version ist really good. Have you any informations for us?

    Thank you!


    • chaos says:


      a new version is coming for sure, but I can’t make any promises on the exact date. Expect something around end of summer, maybe sooner.

  4. Giovanni Medina says:

    this is probably a dumb question, but is it technically possible to make the amiga core better than the original through FPGA? Like improve upon the amiga’s shortcomings? Such as the processing speed, ram, etc. Would it also be possible to do the same with the SNES, if there were an FPGA core of it? If so, i wonder if it would be possible to make games such as starfox run at a constant or near 60fps instead of a 2-20fps.

    • chaos says:


      somethings can be updated to work faster in an FPGA, like the CPU core, but the amiga chipset can’t be updated much without breaking compatibility. Minimig is meant to be a more or less compatible replica of the Amiga chipset, so compatibility is more important than speed.

      I’m not too familiar with the SNES, I guess it depends on each particular game whether speeding up the CPU will increase the framerate.

  5. Mahen says:

    Hi Chaos ! I recently figured out that by combining an xbr filter with a scanlines filter, one could get an absolutely awesome picture on recent screens 🙂 Do you think it could be possible to achieve this in the Minimig core ? 🙂

    I don’t want to sound like a spoilt kid though 🙂 Love you work, definitely looking forward to an update 😉

    Please create a Patreon campaign !!

    • chaos says:


      I’m working toward it. The problem is the unstable CPU interface, and adding another Zorro expansion causes a completely unstable core. So I’ll have to rewrite the CPU interface and SDRAM cache first, before continuing work on the ethernet support.

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