I use a MIDI Portman P/PC and the appropriate Windows driver.  The
device connects to the parallel port of your computer and provides
full MIDI In/Out to any software package.  I've been using this for
years to drive various instruments, including Allen Digital Organs,
my own converted Conn Artiste, and various other portable devices.

I have never experienced any problems with it, and it requires no
external power source, since it is parasitically powered from the
device to which it is connected.  Older, used units may be found on
eBay and elsewhere cheaply.

Bill Leaming