I have been testing lots of old cards lately, and I was just tinkering with a pile of old Paradise PVGA1A ISA 256K VGA cards. I was running through Checkit! tests on each card to be sure they were working properly, but one gave me a funky screen for one of the text modes. Basically, everything was huge and partially cut off, and text was very dark blue on black, when it was supposed to be a medium gray on black. I realized that the switches on the back of the card were set differently on this card so I set them to match the others and it fixed the issue. Long story short, with the help of this page I realized that... big surprise... the default settings (marked with a *) worked the best.
The one that seemed to cause problems was SW1/2 "VGA MODE SWITCHING CONFIGURATION ". Now, my question is... why is "PS/2 Style" the default and the least problematic mode? Why does the "PC\AT Style" setting cause issues with certain DOS text modes? I know that sometimes this third party documentation (most of it coming from TH99) can be incorrect, so I'm leaning toward it being a case of them just mislabeling the settings. Still, if anyone knows why this might be accurate I'd love to know. 😀
I don't think it matters too much, but I'm using a 440BX system with DOS 7.1 (98SE) and the display is a Dell Ultrasharp 2001FP.
By the way, I am absolutely LOVING the 2001FP for working with old video cards. It seems to handle almost everything I throw at it, and even when a certain mode is misaligned or doesn't look right the auto-alignment works amazingly well and even has a single button right on the face of the monitor to correct alignment instantly. Since it is also 4:3, I would consider this a nearly perfect LCD for testing retro gear. A CRT certainly blows it away in many aspects, but if I'm not going for a great gaming experience and just want reliable testing with lots of flexibility, lower power consumption and a small footprint, this is just great.
Now for some blitting from the back buffer.