Thanks for your hint.

>> I had a similar problem when I downgraded from PicassoIV
>> to CV64

Was it causing a: Exception 3 - Store to a not existing Page ?

Shouldn't MorphOS fail in a more graceful way and just
say: mode not supported?

Which is actually what happens if you try to replace
CVision3D with CVision3D.Z3 (instead of Z2) on A1200
+ Zorro2 busboard:

"Hello, Ambient here. I couldn't open a screen..."

I am going to definitely try your suggestion, it could
take a while cause to reopen a Micronik tower and
safely remove all the precious Amiga parts twice
(grex in, grex out once again) it's not an easy task!

In the meanwhile, is there a way I could hexedit the
ambient prefs? Or could somebody just send me
a safe config file with sensible screen mode for CV3D
for me to test before the week-end? Thanks a lot!

Is there a way to force a mode from "startup" ?

btw: should I chaneg something in the CVision3D.info too?
the one that comes with MorphOS 1.4.5 PowerUP has :

BITMAPCACHE=YES
PACKED24=NO
BOOTLOGO=YES
SCROLLMASK=NO

Is thak OK?

@Buleste

Did you try Crumb suggestion too?

How do people that just have a Zorro2 + CV3D setup
(and no g-rex, etc.) setup sort it out? Thanks!

Ciao,
-max