I picked up a 512K Mac system board at the recycler's earlier (hopefully
it's just a "stray" that had been sitting around on a shelf for years, and
someone didn't just trash a complete machine)
It would be fun to see if it powers up, but - for whatever reason - it has
no ROMs. Before I wonder about all the other potential problems, will the
Plus ROMs work? Wikipedia suggests that the Plus firmware was identical to
that fitted to the 512Ke, but the article's open to interpretation over
whether the only difference between a 512K and a 512Ke was the firmware and
the fitting of an 800K drive.
cheers
Jules