I can add a little bit in the way of early deployments of Wayne's
solenoid system.  Shortly after the University of Maryland, College
Park, Maryland, established the International Piano Archives at
Maryland (IPAM), they acquired a Bösendorfer 290 SE ("Stahnke
Equipped") piano to add to their then-respectable harem of reproducing
pianos, which included (if memory serves correctly) a mid-size (5' 8")
Knabe Ampico "B", a similar sized Chickering Ampico "A", a Steck
Duo-Art, a Steinway upright Duo-Art and a Welte (Green? Red?)
Vorsetzer.  Only the Bösendorfer and Knabe remain.

The Kimball Company in French Lick, Indiana, was then the agent and
distributor for Bösendorfer and so, in addition to my maintenance
activities for the pneumatic instruments, I was pressed into service in
trying to solve a problem with the SE.  I don't recall the exact nature
of the issue but I believe it involved some aspect of the sustaining
pedal.

After weeks of component replacement and head-scratching, I somehow
discovered that a strap mounting screw had pierced between two outer
conductors of one of the ribbon cables, shorting the two wires
together.  There were some red faces at Kimball following that.

Although there were grand plans to have visiting artists record on
the SE, the only one I remember was Oscar Peterson, whose recording may
have predated the cable fix.  Maybe that's why the performance will
peel the paint off of the wall.  I believe the piano is still playing
from it's original computer and operating system which probably makes
it the only computer on the entire U of M campus still operating under
DOS.

John Grant
Baltimore, Maryland