Jerome wrote: > I'm writing the milestone 3, but I have never use ioctl function. First, get the old BeOS newsletters (from bebits.com or one of the ftp.be.com mirrors) and read all the articles about device driver writing. Writing (and using) drivers can be tricky. Second, look at the available sample code. See <http://home.concepts.nl/~hollies/midi/drivers.html> for a list of MIDI drivers. Some of them have source code you may want to study. This is all I can help you with for now, because I haven't studied the MIDI driver ioctl protocol yet. Matthijs