> > I have two -3/260s with, I think, 64M each
>
> TME emulates a Sun3 with the Carrera motherboard (Sun 3/75,
> 3/140, 3/150, 3/160, 3/180), and it was my guess that the
> Carrera motherboard had a 32Mb limit ...

Those are true VME-bus systems (not power-only VME like the 3/60),
so the motherboard's onboard limit is most likely immaterial.  The
architectural limit would have come from the addressing capacity
of the processor/MMU, or the VME bus itself, whichever was less.
The practical limit would likely have arisen from the number and
capacity of memory boards that would physically fit in the cabinet
(or that the power and cooling mechanisms could handle :)

I was at one time aware of a sun3, probably a /460 or some such,
which had an astonishing 1+ GB of disk -- likely one of the 3 or
so largest sun3 disk farms in town at the time.  Dunno how much
main memory it had, but I suppose it would have been at least an
order of magnitude less than the total disk space, maybe 128MB.