VGA video output with color classic, trying to get SVGA
I have now managed to get my Color Classic working with a cube video card. I had had lots of difficulty with this, fiddling with various ID lines and trying to imitate an Apple adapter- turns out it's easy, just leave all but the video and h/v sync lines unconnected. The computer then puts out 640x480@60hz, which works (finally!). 640x480@67hz works as well. Problem is, 800x600@56hz doesn't work, despite the fact that I've had the Color Classic display in that mode before, with an LC575 m/b if I recall correctly. The screen just goes blank before it automatically switches back (i.e. it's not just a bad picture, it's no picture at all). I am able to get 800x600@56hz from the video card just fine on a different PC monitor, and like I said the CC board has handled it in the past from a different source.
Anybody venture a guess why it won't work?