VGA over IO Board - sync based on speed?

[deepthaw]

I'm trying to get this working on a CRT VGA monitor, and I've noticed something weird.

If I use vga_scaler it looks like crap. If I disable it, it appears to be displaying at native resolutions, but the image is unstable.

What's extra weird, is the stability of the image is based on what speed I'm running it at. In MS-DOS at the lowest speed, I get an "OUT OF RANGE H: 18.7Khz V:35.8Hz" warning. As I increase the speed, the image gradually becomes more and more stable, with it being the most stable (but not quite perfect) at 100Mhz.

Any ideas? Running to a Dell E772c using the Analog IO Board via VGA. Using the latest cache 29.

[Schyz]

I experience the same issue, either I use vga_scaler or I get speed-dependant refresh rates.

EDIT: After updating MiSTer binary to a recent version I've noticed that the different frequencies behave much better, now I only have issues with 15MHz.

[Caldor]

Hmmm, I will try that then. For some reason when I switch to SVGA it shows... strange colors and such with no relation to the actual screen on the CRT, but it shows it without problem through HDMI at the same time. I made a short video of it.

But I will check if it works in a newer core. In Windows it helped to reduce the settings to 640x480 and 16 colors, but 256 colors and it stopped working. 60hz also does not work for the CRT, but variable works. I have not found a way to get the menu working before using a core. I think I need to look at the settings file. I tried different scripts for different display settings, but there was pretty much just two, optimal and compatible. I guess it might have to be more specific than that. It might also be a problem with the CRT I am using, but it seems unlikely, its pretty standard.

[JimBobMcGee]

Setting output to variable also helped me with my scaling issues. Thank you for this post!