> I rebuilt my kernel by applying the 'madhatter patch' to "mac68k/machdep.c"
> and commenting out an 'if sentence' of "dev/grf_iv.c." The 'if sentence' is
> described in "grfiv_match()" function as follows:
> 
> /*
>         if (sense == 0)
>             found = 0;
> */
> 
> I also confirm to work fine with 832x624 resolution (640x480 maybe). If
> 'madhatter patch' is not applied and only above hacking is applied, then
> X11 works fine with 1024x768 resolution but not with 832x624 resolution.

Ok, looks like we need both the madhatter patch and the above comment and
Quadra video should work fine. Could somebody do a send-pr. I've never had
luck when it comes to having things "stick" in the kernel :-)