changed hardware - HD 3870 not running

[zuz242]

as i had a perfect running system, i had to "upgrade" my graphics

my former gforce 8600gt ran "out of the box", my new ati hd 3870 doesn´t..

i tried installing (on an eternal hdd this time) both zeph 10.5.2 and leo4all with ati 3780 support
ticked but to no avail.

so i wonder how:

1. get osx to boot at all, basic vesa graphics (only tried install without any gfx drivers, -x bootup)
2. fixing / installing ati driver for my sapphire HD 3870 ultimate (passive card, not based on reference
layout). maybe different device id?

thanks in advance

zuz