I decided to figure out once and for all what's going on with fbdev on the 730 systems.
It appears at this point that it's not linuxbios. It is fbdev in combination with sisfb_lite. If I build a normal kernel with fbdev, and boot under normal bios, X11 won't run at all. If I just turn off fbdev, then X11 runs fine. Now to see what's going on there ... ron
