The /NuBus signal addressing, or the lack of decoding thereof, would be your current problem. The NuBus Adapter conflicts with the Video SubSystem of the SE/30.
The "custom NuChip 30 and associated transceivers" could be the problem, as they're used on the IIci and the IIsi Adapter. Both are faster, and more capable I/O buses than the SE/30's, but I really doubt that the speed aspect is your problem.
The IIsi, and very likely the IIci, has the ability to do burst transfers across the PDS when operating as bus master. The SE/30 lacks this feature and I'm guessing the Mac II, IIx and IIcx also lack this feature. These earlier/slower members of the Mac II family used the original NuChip ASIC and transceivers, probably without the ability to do burst transfers over their '030 I/O System (essentially one big "PDS") as well.
What may become necessary to do NuBus on the SE/30, would be to design a NuBus Adapter based on the old NuChip Chipset.
Dunno, more fine reading of the Docs kinda research necessary to come up with a real solution.
Look at it this way NuChip < NuChip 30 < The IIfx NuBus Chipset < The NuBus 90 ChipSet for the Quadra and X100 PPC series.
Backwards compatibility of the ChipSets ain't very likely in my book . . . :-/
My NuBus Adapter is AWOL for the moment, but it only has a socket for the CoPro, IIRC.
What was the rate of the oscillator you under-clocked for the SE/30 trials? 10MHz?
What other thread? :?:
The "custom NuChip 30 and associated transceivers" could be the problem, as they're used on the IIci and the IIsi Adapter. Both are faster, and more capable I/O buses than the SE/30's, but I really doubt that the speed aspect is your problem.
The IIsi, and very likely the IIci, has the ability to do burst transfers across the PDS when operating as bus master. The SE/30 lacks this feature and I'm guessing the Mac II, IIx and IIcx also lack this feature. These earlier/slower members of the Mac II family used the original NuChip ASIC and transceivers, probably without the ability to do burst transfers over their '030 I/O System (essentially one big "PDS") as well.
What may become necessary to do NuBus on the SE/30, would be to design a NuBus Adapter based on the old NuChip Chipset.
Dunno, more fine reading of the Docs kinda research necessary to come up with a real solution.
Look at it this way NuChip < NuChip 30 < The IIfx NuBus Chipset < The NuBus 90 ChipSet for the Quadra and X100 PPC series.
Backwards compatibility of the ChipSets ain't very likely in my book . . . :-/
My NuBus Adapter is AWOL for the moment, but it only has a socket for the CoPro, IIRC.
What was the rate of the oscillator you under-clocked for the SE/30 trials? 10MHz?
What other thread? :?: