How interchangeable are the CPUs in the Wallstreets? Can I drop a CPU from a second series into a first series Wallstreet?
I believe you can
Nope. The Rev 1's have 83 MHz buses, the Rev 2's have 66 Mhz buses. Go figure.
I think they also had a differnet cache.
I believe the only REAL issue is ROM revisions. PDQ supported features not available on the WS I (like interpolated resolutions on the LCD).
AFAIK, the CPUs should be electronically compatible. However, I've never tried it, and I urge you not to do so unless you can afford a new Wallstreet. When I've asked this question before, I've always gotten nebulous answers. That leads me to believe that few people have actually TRIED to swap CPUs and just believed Apple that it can't be done.
We DO know that the ROMs are a problem, though. That's the whole reason for different versions of CPU upgrades between the WS I and WS II...