Zac67 wrote:
I know that some Ramsey registers on the A3000 are only accessible while in supervisor mode - probably the same with Gayle here.
@CLS2086: the 020 has nothing to do with the amount of chipram.
@A6000: I'm not into 68k bus protocols any more, but that's very possible.
This sounds possible... in the schematics, it decodes only the two lower bits, so basically it can detect supervisor and user mode.
Coprocessor may also be a thing, since it has some signals on Gayle.
Thanks for the help to everybody. If someone confirm the answer, please post :-)