hi

cool project!

i did the same with an 16f876a once, here the most important settings :

Code:
DEFINE        OSC           20            ' oscillator speed
define        HSER_TXSTA    20h           ' enable transmit register
define        HSER_BAUD     31250         ' midi baud rate

hserout [$90,$45,$40] ' send a midi comand. noteon ch 1. middle A. middle velocity
this commands and defines are the same on a 12f675

eventually it would be possible to work with the debug command on the 12f675 and you could use the internal oscillator. must be tried. the debug command is the most fastest of the serial commands.
take a look at the pbp manual for setup the right debug settings.

I used this hardware setup

cheers