Hi all, I just subscribed to this list and was wondering if there are people here who have experience with DirectMusic. I am currently developing a DirectMusic driver for a MIDI interface. To test it I wrote a little application that sends out MIDI messages and system exclusive which is then captured by an input (I connect the output to the input with a cable). I then compare the input with the output to see if everything works as it should. This goes reasonable well, except for the system exclusive. Whenever I send blocks larger then about 5000 bytes strange things start to happen. Always at the same point I receive an unexpected byte at the input (after having sent 2161 bytes). At first I thought the error occured within my driver. I use a debug version that logs every byte it sends out and that comes in. After carefully going through the logs I can only conclude that the driver sends all the bytes in the right order. Somewhere in the portcls layer something goes wrong. The problem is perfectly reproducible. If I have the same input it always goes wrong at the same point, with the same data. To me that indicates that it's not a timing issue. The problem is that I don't have any other DirectMusic driver to compare results with. I have a few Soundblaster compatible soundcards lying around but they only have emulated MIDI ports when using DirectMusic. I tried to get the Microsoft sample driver to work but I guess that Soundblaster compatible is a pretty loose term. They refuse to work with that. If anyone has experience with this I'd like to share knowledge. Evert van der Poll ****************** WDMAUDIODEV addresses: Post message: mailto:wdmaudiodev@xxxxxxxxxxxxx Subscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=subscribe Unsubscribe: mailto:wdmaudiodev-request@xxxxxxxxxxxxx?subject=unsubscribe Moderator: mailto:wdmaudiodev-moderators@xxxxxxxxxxxxx URL to WDMAUDIODEV page: http://www.wdmaudiodev.de/