AGA MK2cr - Native resolutions?

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Don't Panic. Please wash hands.
  • Is there any way to set the AGA Mk2cr to use native resolutions just scan doubled & flicker-fixed? Maybe limited to the analogue VGA lines? From the best I can determine the maximum actual video signal is roughly 1500x568 (PAL Super Hi-Res interlace) with the native screen modes (NTSC & PAL.) In the case of my machine, it is actually 1500x484 (NTSC.) Though, in theory, my system can operate in pseudo-PAL mode with a resolution of 1500x568, the clock crystal will still be NTSC though.

    Since I cannot figure out how to set up scaling, which I prefer to avoid anyway, and I'll be attaching this to a CRT monitor (which should be able to handle those resolutions - according to the manual,) a native resolution mode would be appreciated. The only limitation of the monitor is that it cannot go below 30 Hz, so the scandoubler is a must.

  • You cannot set up scaling, as Indivision AGA MK2cr is not a scaler. It is a frame buffer with built-in flicker fixer.

    If you use a CRT monitor, please make sure to switch off DVI signals, as those may interfere with the analogue output with certain DVI-I->VGA adaopters. Some (very cheap) adapters do not properly terminate the DVI signals, causing vertical stripes in the picture.

    For each input mode (Amiga screen mode) you can select/edit a VGA output mode with the config tool. If you want to use such a big overscan area, you will need to configure an output mode with sufficient screen size and output clock rate first, then assign it to the SHires-PAL mode that you'd like to use as "source".

    While your on-board crystal is NTSC, the flicker fixer does not care. It will generate a multiple of that clock rate for the output and not look at the actual NTSC or PAL encoding. Luckily, Lisa presents the pixel data "in clear text" at the output pins where Indivision grabs the picture data, so it's perfectly fine to choose a PAL mode on an NTSC board.

    You might want to try HighGFX before you fiddle with your own output. This produces a good aspect ratio - definitely better than the aspect ratio you're planning.


  • The only reason I brought up scaling is that I could not find an output resolution that matched the input resolution. Anything smaller would cut off part of the screen, and everything larger would leave it floating with a black border. OK, didn't see where I could add to the VGA modes. That was the answer I was looking for, thank you :)

    Just to note, I'm not actually using those really high resolutions, I was just listing them as the normal limits as far as I can find. I usually go with Hi-Res interlaced overscanned to 640x480 (for Mac emulation for the most part.)

  • Hello,

    I use Amiga´s PAL Interlaced mode, mapped as 1280x1024 60Hz VGA mode. That my 17" 4:3 LCD monitor (native resolution 1280x1024) displays perfectly as full screen, exactly 2x pixel size of Amiga, so it´s sharp.

    Is it possible to define non-interlaced Amiga PAL (e.g. 320x256) such way it is diplayed the same way - full screen on my monitor ?

    Thanks for any advice.

  • A 320x256 screen should be able to use the exact same setting as your other PAL setting; just copy that mode, maybe add scanlines (instead of line doubling), and you should be done. Indivision AGA does not make a difference between lored, hires or S-Hires. It will always take SHires pixels, so a lores resolution from the Amiga results in Indivision AGA seeing four identical pixels next to each other.

  • The last reply was more than 365 days ago, this thread is most likely obsolete. It is recommended to create a new thread instead.