Radeon with dual DAC - how to trap/start flat driver

I’m trying to start Photon on Radeon 9250. I know this is not supported
chipset, but flat driver would be enough. This card has dual DAC so it
appears as two video cards in system. Crttrap cannot switch monitor back
on after running but writes trap file. There are entries in trap file
only for only one video card and only low resolution vga (no flat, no
radeon). Is there any way to try to trap (and then use) the second card
(I suspect that first card/DAC is in some way non standard)?

TIA,
Greg Wróbel