Greg Mayman wrote in a message to Roy J. Tellason:


 GM> Natty! I have detailed diagrams of similar things operated by
 GM> pneumatics that were used on pipe organs about 100+ years ago.
 GM> Although they only had two positions, on or off.

If you're interested in knowing about it, a lot of the old pneumatic
controls on pipe organs are still in use.  I played one this week.  Works
nicely, but it's scheduled for conversion to electronic/electromagnetic
operation some time this year.

    Everett 
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