Display problem

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clarkkent
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Display problem

Unread post by clarkkent »

I‘m new to miSTer and am right in the middle of configuring this and that.

I have display problems with the Amiga core.

My setup is a miSTer with 128 MB SDRAM connected with a HDMI-to-DVI cable to a Benq 912BL (a rare 19 inch monitor able to display 480i and 576i in 50 Hz). I‘m using the PAL mode to get butterly smooth scrolling.

In the MiSTer.ini I‘m using these settings:
video_mode = 1280x1024 60Hz
video_mode_ntsc = 720x480 60Hz
video_mode_pal = 720x576 50Hz
vsync_adjust = match core frequency
vscale_mode = use integer scale only
dvi_mode = on
everything else off

I‘m using BetterWB on a harddisk image and I have a second harddisk image with ClassicWB.

On BetterWB it works when using DoublePAL highres, I get a good undistorted picture in 640x512 and can start games via WHDload in PAL or NTSC. But the games have some graphics glitches with these setting.

But as soon as I want to use the MiSTer specific resolutions (as written in the instructions at the core github), my monitor doesn’t want to switch to a higher resolution than 720x576 (the resolution set is simply shown distorted in the 720x576 mode). Same on BetterWB and ClassicWB. The MiSTer display resolution info at the upper left corner always shows about 1500x280 or something (why?), which translates to 720x576.

Is there a way to force the Amiga core to use the requested resolutions but still able to use the 50 Hz mode for games? And why are the display modes that the display driver installs on the Amiga side using 150 Hz or more? These can not be displayed correctly in my opinion.
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Re: Display problem

Unread post by FoxbatStargazer »

Just to clarify are you asking about Render To Graphics support in the Amiga core? I don't know a ton about that feature, but what I do know is that Mister's scaled output cannot differ from whatever you set as the video_mode. So yeah if you tell it 576p, it will try to scale whatever to that.

Ideally your video_mode should be equal to your flat panel's full, native resolution. However some flat panels expect extended blanking to activate native PAL refresh. As an example, the included video_mode 0 is 720p@60hz (NTSC) and mode 7 is 720p@50hz (PAL). Even though the resolution is identical, and letting vsync_adjust=1 or 2 will let the core set the refresh rate, you still need to send mode 7 to some displays so that the extended blanking activates smooth PAL scrolling. There is also a pair for 1080p (8 and 9) and a few other resolutions. If one of these modes gets the scrolling right, you might look into creating a custom modeline matching your display resolution, and by tweaking the blanking settings yourself, you might get it to display 50hz proper.
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clarkkent
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Re: Display problem

Unread post by clarkkent »

I found a better solution:

Added different settings for the minimig core to the MiSTer.ini
video_mode_pal=7
vscale_mode=0

With these settings I can set a native 1280x720 resolution in Workbench and a correct aspect PAL mode with 50 Hz.

Only one thing:
There is no MiSTer graphics mode 1280x1024 in the Workbench monitor prefs available. Only 1024x768, 1280x720 and then 1600x1200 and higher - but no 1280x1024.
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