About the 8pin mini din plug.....
Some newer synths  have a plug on the back which  allows you to connect a
computer  (Amiga, Macintosh  and PC compatible)  directly to  your synth.
In this case the serial port on your computer is used to communicate with
your synth. This communication is  bi-directional. This means you can use
is for Midi-in and Midi-out. However, you'll need to set some switches on
your  synth to set it's signal  detection to either RS232 (voltage level)
or RS4xx (current loop, don't know the number right now).