Probably this problem is independant of OS-9 but I don't really know.
The MVME335 is located in A16 (short IO of the VMEbus and not in A24): $FFFF.xxxx. It's jumpered to $FFFF.F8xx. Observation: I cannot use $FFFF.00xx because the MVME177 occupies the first 16bytes. This is not documented. I don't know the cause of this unexpected behaviour. But I
see also some other strange behaviour: In Rombug I want to read the
address space of the MVME335. "d $ffff.f800" displays the first 16
bytes, than Bus error. I can read the following 16bytes by typing "d ffff.f810" and so on. There is always a bus error after reading 16 bytes
(a single cache line?).
1. Do you have an addressing overlap?
2. Are you requesting, e.g., a 16-bit transfer from a device that
only supports 8-bit transfers?
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