Minimig on v2

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Don't Panic. Please wash hands.
  • What level of CPU is a realistic goal for this? Could it do a 68020 or 030

    The Minimig core already has a 68020-level CPU (though not perfectly compatible) which runs at roughly 40MHz '030 speeds.


    The fastest CPU I've seen running this kind of FPGA so far is a pipelined MIPS core complete with branch prediction, roughly comparable speed-wise to a first generation Pentium. The Vampire's CPU core runs on a comparable (though larger) FPGA, and is, I believe, faster still.

  • I get an error whilst trying to run the Minimig core.


    I get a red screen after loading the kick.rom file and an error message saying "Exiting bootloader..." --> "Incompatible Menue firmware!".


    I've used the mot recent 2019-03-21 files. And a 1.3 kick rom image from Amiga Forever.

    OK that's strange - after the "Exiting bootloader..." line appears it shouldn't be possible for the incompatible firmware message to appear, because at that point the boot code should vanish from the Amiga's memory map, and hand over to the newly-uploaded Kickstart.


    Standard advice when hitting problems with an FPGA core is to try a different SD card. I don't think it will help in this case, but just to be sure, could you try it?


    Also, could you try this .rbf file instead? It's exactly the same thing but compiled with different optimisation settings, which re-rolls the dice regarding the minimig core's build-to-build stability issues. If this behaves in exactly the same way, then report back and I'll see what else we can try.


    Is anyone else having problems?

  • Thank you for your quick reply. I tried a different SD cart like you suggested, but that didn't make any difference. Also with the new .rbf file the same issue occurs.


    Maybe, I'm doing something wrong? I'm quite new to this ;)


    This is what I have done:

    I've put both the menu software and a kick.rom file in the root of the SD card.

    I have flashed the core in slot 1 (B) with the ChaCo software, while the TCv2 was connected to the C64 and the SD Card was removed. I didn't select any other options in the ChaCo software. After the flashing was done, I turned the TCv2 off.

    After turning on the power of the C64, I started the core with pressing B. If I go to the menu of cores, I see the core listed, but nothing happens when I press return.

  • you also need the OSD_CA01.sys in the root of the SD card, perhaps it should go into the distributed zip :)

    Yes, indeed - a corrupted OSD_CA01.sys file could cause this, so definitely worth trying the attachment here. But I suspect it's not that - I'll do a build with the Action Replay disabled, since I remember that module causing me grief a few years back.


    Thanks for testing.

  • @robinsonb5. Many thanks for all the work. Is there something a site or pdf from a how to install... and requirements for the minimig core? As far as I can understand I followed the known instructions but nothing happens when I turn on the TC V2.

    Many thanks.

  • @robinsonb5. Many thanks for all the work. Is there something a site or pdf from a how to install... and requirements for the minimig core? As far as I can understand I followed the known instructions but nothing happens when I turn on the TC V2.

    Many thanks.

    The Chameleon's user manual is here: http://wiki.icomp.de/wiki/Chameleon#User_Information


    You should flash the .rbf file to a core slot - ideally slot 1 or higher. (Correct me if I'm wrong, Jens / Tobias - flashing a core to slot 0 will replace the default C64 core?)


    The OSD_CA01.sys file needs to go on the SD card along with a kickstart ROM file, called kick.rom


    By default the Minimig core puts out a scandoubled PAL video signal, 31Khz horizontal, 50Hz vertical scanrates, and not all monitors can cope with that. Try holding down F1 on the PS/2 keyboard while pressing the reset button to force scandoubled NTSC mode (60Hz) which more monitors can cope with, F3 for 480i NTSC video, or F4 for 576i PAL video.

  • Using the sys file that Tobias posted did the trick. It also is different in size from the one from the zip file from retroramblings. Now to find a proper keyboard that works :)

  • Quote

    You should flash the .rbf file to a core slot - ideally slot 1 or higher. (Correct me if I'm wrong, Jens / Tobias - flashing a core to slot 0 will replace the default C64 core?)

    yep. of course if thats what you want to do - you can still do it. but you cant start other cores (except with chaco) then :)

  • yep. of course if thats what you want to do - you can still do it. but you cant start other cores (except with chaco) then :)

    RIght, that's what I thought. I was confused because out-of-the-box the "Launch core" menu (and chacocmd --info) shows slot zero as "empty" rather than occupied by the C64 core. I suspect that might result in people replacing the C64 core without meaning to.

  • @robinsonb5. Thanks for the feedback. The manual I found before.
    The part I was missing for myself was this: "By default the Minimig core puts out a scandoubled PAL video signal, 31Khz horizontal, 50Hz vertical scanrates, and not all monitors can cope with that. Try holding down F1 on the PS/2 keyboard while pressing the reset button to force scandoubled NTSC mode (60Hz) which more monitors can cope with, F3 for 480i NTSC video, or F4 for 576i PAL video.


    This pointed me to the right way. Many thanks

  • sing the sys file that Tobias posted did the trick. It also is different in size from the one from the zip file from retroramblings. Now to find a proper keyboard that works :)

    That's great news! Could you do me a favour, though - could you try re-downloading from retroramblings, and testing again with a fresh copy of the firmware from the zip file? It should work, so I suspect either the download got corrupted or truncated, or the file got corrupted when written to SD card.

  • Quote

    I was confused because out-of-the-box the "Launch core" menu (and chacocmd --info) shows slot zero as "empty" rather than occupied by the C64 core. I suspect that might result in people replacing the C64 core without meaning to.

    Yeah, it seems jens accidently used a very old chacocmd (which didnt update the core info text) to flash them.

  • I did just that of course, but forgot to mention it. Sorry. The one from retro ramblings is 68.91 kb and the other one is 57.36 kb. Hope that helps. Thanks!

    Hmmm, very strange - that version definitely works here. What platform are you using to extract the zipfile?

  • I don't know if it's allowed or interesting to post the following.

    @robinsonb5


    Finally I got your core working. Very nice. The 3.1.4. rom is also working fine.






    Just 2 questions if I may:


    - Is it possible to get the Amiga OS on full screen? At the startup from the minimig core and the Amiga OS there are black borders on the screen.

    I tried with the F1, F2, F3, F4 keys but I don't get it better as on the picture. Perhaps it's my old monitor?

    - I use the TC v2 in stand alone mode (for now). Do you know if it's possible to boot straightly in the minimig core instead of via the TC menu?

    Many thanks

  • Just 2 questions if I may:


    - Is it possible to get the Amiga OS on full screen? At the startup from the minimig core and the Amiga OS there are black borders on the screen.

    It's not possible to adjust this from within the core - but does your monitor not have sizing options on its control panel? If there's no horizontal size look for a pixel clock option - this sometimes adjusts the horizontal size as a side-effect.


    On workbench you can always use the overscan prefs to use more of the screen.