There were a few cool display modes you could make with VGA if you punched the CRTC the right way. I liked using 400x300 256 colors at 87Hz. You needed a d

There were a few cool display modes you could make with VGA if you punched the CRTC the right way. I liked using 400x300 256 colors at 87Hz. You needed a decent monitor to handle it. If you swapped pixels of similar luminosity every other frame, you get a bunch of new colours looking fairly solid. If you swapped between large luminosity values then you get a 44Hz shimmer.