Over in this post I have a weird old VGA card with custom ribbon connector to an LCD working finally, transplanted into a modern(ish) machine but powered off of the original PSU.

The card has 8 DIP switches on it that allow you to specify (among other things) what graphics mode it runs in... I have identified CGA, EGA, MGA, VGA, and VGA protected. When running in any of the non-VGA modes, console fonts in a modern Linux or FreeBSD or in FreeDOS are just fine, with noticeable chunkiness in CGA mode, for example. But in the VGA modes, the fonts become garbled:

You can see things happening when you type or when output appears (as much as you can get it to when you aren't exactly sure what you're typing, anyway). So it's "live", just not displaying right.

I believe this is maybe a font or character set issue, a mismatch between old hardware VGA modes and modern framebuffer-type console displays. Does anyone know how I could debug this? I could get into a bunch of Linux and FreeBSD kernel and other boot settings I've tried, but I'll hold off on that for now.