Different X modes on the Mac platform??

[Known Human Nick Rusnov <nick@intus.net>]

Wow, a previous poster referred to booting into different modes on a Mac.. I've
been trying to figure out how to, say, get X into the hires mode that MacOS can
do.

So, how do I do it? I've got a beige G3 mac, appearently with an ATY,mach64_3DU
(so says /proc/fb). How do I switch modes and or get fb stuff to work? Its stuck
in 832x624-173. 

thanks!
nick