[sdiy] MIDI activity indicator circuit

[Hallvard Tangeraas]

One of my current projects is to rack-mount an Atari ST computer with
all sorts of extra hardware goodies added, making it the ultimate MIDI
computer (in my opinion) in a sturdy, compact 19" rack enclosure
without having all sorts of bits and wires hanging out of it.

One of the things will of course be added MIDI capabilities. I use
Notator SL (see my signature for a mailing-list on this software which
I run, in my signature) and with some add-on boxes from C-Lab I now
have loads of extra MIDI in and out ports.

Now, finally my question...
I would like to add MIDI activity indicator LEDs for each IN and OUT
port, flashing/lighting up whenever a MIDI signal goes through that
port. Does anyone have such a circuit available?
I know that simply connecting an LED to the MIDI pins will make it
flash, but (a) it doesn't light up very well, and (b) I don't want to
put any extra load on the MIDI circuitry or interfere with the signal
in any way as I believe this is just a "quick and dirty" solution. I'm
looking for a proper, stable solution, but hopefully nothing too
complicated or expensive if possible.


Hallvard
-- 
Notator/Creator SL : <http://www.notator.org>
Atari Launchpad    : <http://launchpad.atari.org>