iMac rev. A video timings

[Benjamin Herrenschmidt]

> Strange. You could try adding
> 
> 	Option "UseFBDev"  "true"
> 
> to the /etc/X11/XF86Config-4 file (device section).
> 

This is a mach64 chip, XFree mach64 driver doesn't support UseFBDev
(the maintainer for this XFree driver hates fbdev's for some reason,
though it seems he also hates linux, so...)

Ben.