Here is HEX-80 format code of non working program:

:10001A00758920758BFF758DFF758850759870D21C
:02002A008E2224
:1000030012001AE4F509F50AF50BFFF5A03098FD87
:070013000FC2988FA080F6D8
:0300000002002CCF
:0C002C00787FE4F6D8FD75810B0200031C
:00000001FF

Midi out from soundcard is working with Midex8 conected on other PC also running MidiOX.

So Midi out is connected to optoisolator, and then after pullup resistor on RX of uC.

But here is the problem. 15 min ago i connected signal, after optoisolator PC817 which should be connected to RX, directly to Midex on other PC. Upon sending Midi On Off messages, other PC is receiving wrong bytes.

Reason i used PC817 is that he do not provide pin for base of output transistor like CNY or 6Nxx. This pin caused me some flase triggering, even when i used some resistors to GND line.

So optoisolator is the problem, guess code is working, it's simple enough.

I'll try 6N139 again and will report results.

BTW is there a way to upload some gif schematics on this board, and a way to skip auto text formating that ate my spaces in the C code making it harder to follow (i do care for readable code!)

HM, ok i am seeing it now, the HTML tags... usefull stuff.

Thanks