While I've been toying with internal video stuff I've noticed that the same
exact config (my little 100 meg test zip) that will run X on machines like
my IIvx or the Quadras will blow up on mapping the video buffer on machines
like AV's.

What's going on? I checked the address and it looks valid (0xBnnnnn or
something like that). I've also heard of similar problems on machines
like the 630's.

I think it might be the kernel has some kind of lock on the memory already
but I'm not sure. Any ideas?