Hi All, I'm relatively new to driver development and I'm trying to understand how a MIDI driver is written for a USB device on Win XP? If I understand correctly from MSDN and other sources, the USB interface is already supported by Win XP, and an API to send data over USB is available (through URBs)? If that is the case, can I just create a user-mode MIDI driver and use the USB transfer API to transfer data over the USB bus, which means I do not need to implement anything at the kernel level? I would appreciate any clarifications on this topic, as well as some example code, tutorials, documents, etc that might help to clear up everything. I have USB Complete here and the WDM book by Oley. Thanks, Bert ****************** 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/