[sdiy] EFM MIDI-Gate?

[MTG]

Assuming the schematic is correct. How does it compare with other people 
doing similar things?  What does the data sheet say?  Another thing, if the 
output is open collector (drain) and the PIC isn't installed you won't see 
anything because there is no pullup. Off the top of my head I am only 
familiar with the PC900, so I don't know what that pull down resistor is all 
about.

Also, I'm kind of surprised you can see the input since it's a current loop. 
Generally that's pretty hard to scope.

GB