Greetings MMDers,  On 19 Nov last year, having built a 16-note air/steam
calliope, I contacted MMD requesting ideas on how to automate it through
a MIDI system.  My thanks to Robbie Rhodes, Mike Knudsen, Harald Mueller
and John Wale who gave good advice: I now have a much admired
workable system.

The jw MTP1 32-note board is ideal and a simple DC power supply easy
to make with today's selection of transistors and other components.
The 24-volt solenoids were free from a discarded 20-sheet paper sorter
off a copier.  Although the solenoids were rated at 0.7A I found they
had enough pull at 18V which met the .5A recommended output to the
MTP1.

I have a Mac iBook and downloaded a programme, Intuem 2, from the 'Net
which drives MIDI formatted tunes to the MTP1 through a USB device.
I was able to produce 16-note tunes in MIDI format by either using the
iBook keyboard and a programme called iPiano, but more professionally
by using a Technics keyboard through the MIDI USB device into the iBook.  
My typing is two-fingered and music arrangements are similar -- not
exactly classics!  Therefore the next job is to increase the calliope
to 20 notes and purchase already arranged 20-note music.

It has been an interesting project and, as Mike Knudsen said, fun
joining the 18th and 21st century techniques (with all due respect to
those of you I see on MMD who are original/traditional perfectionists
to the core).

One last point is that I think MIDI arrangements are only available
on floppy diskettes.  These are becoming an outdated format and not
readable on most Macs.  I would appreciate any leads to more recent
formats such as chips, DVDs or purchasable downloads from the 'Net,
through which I could get professionally arranged 20-30 note MIDI
tunes.

Again, thanks to those who helped

John Beauchamp
New Zealand