I have my core module connected directly to Gameport as suggested here : http://www.ucapps.de/mbhp/mbhp_midi_gameport.gif My core behaved normally, sent sysex requests for upload, but i did not manage to get MIDI IN working. Core passed all MIDI debugging tests, so I turned to PC-side. Tried new drivers for soundcard , flashed bios ( poor realtek AC97 onboard soundcard), considered cabling and grounding issues. Nothing helped. Loopback test worked only if I connected Rx and Tx directly on Gameport with 470R resistor , but not with short-circuited Rx Tx pin of PIC-socket (got only corrupted MIDI data) After 2 day long debugging i tried to disconnect R6 and everything worked perfectly. Dont know about logic levels of MIDI , but It seems to me , MIDI IN can not work (J11/Gameport connection) with parallel Tx(Gameport) and R6(+5V) on Rx pin of PIC. What do you think ? anyway , thanx for great project Thorsten