Why Do Some Arcade Games Have a Garbled Display on My Arcade CRT?

[MrConkin]

Hey I'm pretty new to MiSTer. I have an arcade cabinet with a 29" CRT monitor that I've hooked a MiSTercade into. Loving it so far and almost have it set up to my liking. One issue I'm encountering is that some arcade games have a garbled picture when I load them. Even the MiSTer menu is garbled once I load the core. In some cases it's a mild (but still unplayable) vertical scroll and in others you can't even make out what is happening. Can anyone Eli5 what's happening here? Is it something I can address or is it that the specific cores I'm loading aren't compatible with my CRT due to region specifications or something? After doing some reading it seems like configuring a specific video_mode in the mister.ini file might help, but I have no idea what the series of numbers are used for there so any tips would be appreciated.

Here are a list of cores I'm experiencing issues with. It's not comprehensive, but maybe indicates a pattern:

• Bad Dudes vs. Dragonninja (US, Rev. 1)

• Dragon Breed (JP)

• Gaia Crusaders

• Gallop - Armed Police Unit (JP, M72 hardware)

• Indiana Jones

• Marble Madness (set 5 - LSI)

• Ninja Spirit (JP)

• Pang

• Prehistoric Isle in 1930 (W)

• R-Type (W)

• R-Type II (W)

• Robocop (W, Rev 4)

• Secret Agent (W, Rev 3)

• Super Pang (W, 900914)

• Thunder Heroes

• X Multiply (JP, M72 hardware)

[Lloyd2084]

MiSTer closely outputs the frequency and resolutions of original PCBs. If you had the PCBs in your cab you’d have to regularly tweak pots to get an image.

Simply tweak h / v hold until the picture stabilises.

There are options in the MiSTer menus to force non-native frequencies but I’ve never bothered with them as accuracy is more important to me.

[thorr]

You could try this in your MiSTer.ini... Create a section for each core with it's core name:

[corename]
refresh_min=59
refresh_max=60

I didn't personally try this, but it might work for you. Only do this for problematic cores. If you want to try them all at once, you could put [arcade] instead of the core name, but be sure not to leave it this way because then it would affect all arcade cores and you definitely don't want that.

Also, if there might be PAL/NTSC cores that you might need to switch the setting for in the core menu. For example the Commodore 64 core defaults to PAL and needs to be changed to NTSC in order to work on my NTSC screen.

[MrConkin]

MiSTer closely outputs the frequency and resolutions of original PCBs. If you had the PCBs in your cab you’d have to regularly tweak pots to get an image.

Simply tweak h / v hold until the picture stabilises.

There are options in the MiSTer menus to force non-native frequencies but I’ve never bothered with them as accuracy is more important to me.

My hero. I didn't realize different games would need different v holds. Tuned it a bit counter clockwise and it fixed all the games I was having issues with. Hoping it didn't mess with any of the ones that were working but we will see.

You could try this in your MiSTer.ini... Create a section for each core with it's core name:

[corename]
refresh_min=59
refresh_max=60

I didn't personally try this, but it might work for you. Only do this for problematic cores. If you want to try them all at once, you could put [arcade] instead of the core name, but be sure not to leave it this way because then it would affect all arcade cores and you definitely don't want that.

Also, if there might be PAL/NTSC cores that you might need to switch the setting for in the core menu. For example the Commodore 64 core defaults to PAL and needs to be changed to NTSC in order to work on my NTSC screen.

Tried the refresh change and it didn't work but thanks for the suggestion! I did see some PAL/NTSC settings so will look out for those if I'm seeing odd behaviour.