John Ravert, Sr. asked after the Octet UM0 MIDI interface.  A few years
back I sort of took over the unofficial support for these interfaces
after the passing of Ron Perry.  While I purchased all the remaining
program ROMS and spare parts in the local surplus store, my Windows 95
machine stopped booting.  This broke my ability to re-program the
Octet circuit boards.  It got to the point where it was not worth the
time spent.

There are other newer MIDI interfaces, such as those distributed by
Bill Klinger, that are much better.  Most modern systems are based on
the same chips used in the "Arduino" electronics modules, which are
sort of Lego blocks for electronics.

Before I took over the unofficial Octet support, I wrote a compatible
interface that ran on the same chip as the Arduino.  I think this is
on GitHub; if it is not I can put it there: https://github.com/  Even
this code is obsolete as it is written in Assembly language rather than
the more modern "processing" language which what is the C++ variation
Arduino uses.

For another project (which is simply an Arduino to be plugged into a
pipe organ when the console is not connected) I did some searching for
basic MIDI output from the Arduino.  I found dozens of examples of how
to create MIDI interfaces.  What took me months if not years to learn
and develop can now be set up in a few hours or days.

At close to 40 years of age MIDI remains the de facto text or ASCII
equivalent of music notation.  It is taught as part of programming in
schools and workshops all over the world, especially in India, where
students are introduced to state machine programming by implementing
the device protocol.

Most of these do-it-yourself projects are based on the same chips
used in the Octet boards: the 74HC165 for input and the high current
versions of the 74HC595 known as the TPIC6B595.  In the modern world
these are called SPI serial expanders.  These are also used to create
scrolling displays  of lights.  (MIDI was created to sync the control
of lights to drum machines in 1970s discos.)

The costs have also dropped significantly as one could make something
like the Octet UM0 for under $40.00 USD by using the equivalent Arduino
and Shields processors.  When first sold the UM0 boards cost close to
$300.00 USD.

Julie Porter