The recent post about the mystery perforator is really not a mystery at
all.  The whole thing, minus the electronics, was built by the American
Automatic Typewriter Company of Chicago, Illinois.  The pictures are
interesting but I would certainly like to see a piano roll made with the
machine.

It actually was designed to replicate rolls for the Autotypist automatic
typewriting machine which was vacuum operated and used many player piano
type components.

I serviced one for years here in San Antonio, Texas.  Its purpose was
to duplicate a roll for the Autotypist so the operator would not have
to type a number of rolls to place on multiple machines in her care.

Paper advance was via a large ratchet wheel which was advanced by a
rather large pneumatic operating on 4.5 inches of _mercury_ -- not water
-- vacuum.  You did not have to concern yourself with paper buildup as
the only music produced was the clatter of the typewriter.

They were built like tanks with all hard rock maple components and were
designed to last forever.  The first word processing machines killed the
demand for them and the magnetic cartridge typewriters produced by "Big
Blue" assured their demise.

Ed Gaida
San Antonio, Texas