William Donzelli wrote:
   That would be nice to see ... are there any
valve computers
  up and running still? 
 In Britain and Germany, at least. I know of none in North America. 
 
Does the CHM have a complete 'large'-category tube system that could
conceivably be made to run again?
When I spoke to Paul Pierce a few years ago he hoped to get his 709 running
again, but I think he was viewing it as a retirement project.
I would hope some of those smaller drum machines (Bendix, LGP-xx, etc) which
are still around in some number would run again. (Yes, there's the one in
Germany). IIRC, Tom Jennings had an LGP-<something> he was working on.