CRT VGA Setup using Expansion IO Board (INI File)

NovaCoder
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CRT VGA Setup using Expansion IO Board (INI File)

Unread post by NovaCoder »

I've been playing around with virtual Amiga 1200 hooked up to a CRT via the IO Board.

I have to change the MiSTer.INI

forced_scandoubler=1

To get it to display anything at all on the CRT.

After that it appears to work fine, PAL games and demos run at the expect 50 Hz for the desired smooth scrolling but I've noticed that certain Amiga screen modes (eg HAM8) just result in a black screen with no out of range errors shown by my monitor. This also happens if I try and view a picture using a separate Screen or if I'm using the 486 DOS core to display the command prompt (just get a black screen).

If I then change this setting:

vga_scaler=1

It will now correctly display HAM8 screen modes and pictures in a separate Screen (and display the DOS command prompt using the 486 core) BUT now everything is running at 60 Hz, even in PAL mode??

Anyone know how to setup the MiSTer properly to display on a CRT?

Thanx

NovaCoder
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Re: CRT VGA Setup using Expansion IO Board (INI File)

Unread post by NovaCoder »

I have managed to get somewhere with this by using a different config for different cores (override).

Still not perfect though..

I have found that if I put the Amiga in 'NTSC' mode in the core menu it fixes all of the 'black screen' issues in the MiniMig core but of course all PAL games now run at 60Hz which isn't what I want.

I think this is a bug in the MiniMig core, at first I thought it was a problem with my monitor but now I think this 'black screen of Doom' is a bug.

I will carry on fiddling around in the persecute of salvation.
NovaCoder
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Re: CRT VGA Setup using Expansion IO Board (INI File)

Unread post by NovaCoder »

Update:

I've just thought of a workaround to my problem.

You can specify that WHLDLOAD using a PAL screen mode even when running on an NTSC Amiga 1200 so in theory if I sent the core menu to NTSC and then WHDLOAD to PAL it should resolve the black screen issues and still run games at a smooth 50Hz.
akeley
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Re: CRT VGA Setup using Expansion IO Board (INI File)

Unread post by akeley »

I presume you are connecting to PC CRT monitor?
NovaCoder
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Re: CRT VGA Setup using Expansion IO Board (INI File)

Unread post by NovaCoder »

akeley wrote: Sat Sep 05, 2020 8:09 am I presume you are connecting to PC CRT monitor?
Yep CRT VGA PC monitor in full effect.

It seems that the MinMig core has a problem displaying interlaced screens (including HAM8) on a CRT, I just get a black screen with no out of range messages

Everything else is working now that I've tweak the INI file, PAL games are 50Hz and are perfect. Other cores (eg Genesis/SNES) are running at 640x480 60Hz and looking lovely on the old CRT :mrgreen:

I can't quite get a perfect Workbench screen mode, even after a lot of fiddling around with overscan settings that best I can manage is an off centered VGA Only + Multiscan 640x480 display, when we eventually get an RTG driver that will be a non-issue :idea:
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