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Old 15 April 2013, 08:52   #2055
Join Date: Jun 2010
Location: out in the wild
Posts: 1,133
Originally Posted by keropi View Post
thanks for the explanation, but still after switching to "Hires" I get this on a 1024x768/60hz screen:
You set the width to 512, so Indivision must put 256 pixels left and 256 pixels on the right in order to get the 1024 pixels "left to right" that the output screenmode is supposed to have.

Further, you have switched line doubling to "on" with every other line at 75% brightness. However, you already have an interlace screen that puts over 530 lines into the framebuffer. After line doubling, this is 1060 lines. Naturally, this does not fit on a 768-line screen, so it's cropped at the bottom. Switch off line doubling for interlace, and you'll see the rest of the screen.

Originally Posted by keropi View Post
I have set the width to 664 and for some reason height was 572
If I put height=534 (the actual native resolution is 664x534) then the screen does not receive a usable image.

If I put height=535 then I get this , with the image shifting to the right (still missing from left and lots from bottom)
You are missing lots of pixels on the left, because your output window has an offset set to 68. This means: The left 68 pixels are put in memory, but they are not displayed.

This - in combination with other settings - is causing "not usable display", because you are already in a tight corner setting here: If the output stage of Indivision AGA MK2 finds that the line in memory has ended, then it ends the actual output line in order not to display any memory-crap (people complained about this before). This will cause the output frequency to be higher than calculated, and it may exceed the capability of your monitor.

Let's do some calculation:
there are 664 pixels in the line buffer. You skip 68 of them, so 594 pixels remain to be displayed. You still tell the flixerfixer to display 664, but this amount it just not available in the framebuffer (there's nothing to display at the end of the line!). It may actually be an FPGA core bug that the right black border is not displayed in that case, causing even shorter lines and even more critical frequencies. I'll investigate that.

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