>Hmm, from reading ite_rt.c, I get that the chip uses the read/write
>cycles of the CPU, could it be that the Retina required some sort of
>wait-states at the speed your CPU is running (which is?) which your
>accellerator doesn't adhere to?  If so just slowing down the code in
>screen_up would suffice, maybe redo those "addqb"s to a load'n'store
>pair?  I'm way off my competence platform here, HW-knowhow has never
>been my best skill.

My '040 runs at 33 MHz. Those 'addqb' statements in the code you mentioned,
are they a sort of 'wait loop' or what ? 
When I still had my 25 Mhz '030 it worked ok. So maybe it is the fact that my
CPU is 'too fast' now ;^)

Can I just add some more of those 'addqb' statements to check this ??

/John