Hi guys, quite a while ago, I joined this mailing list to ask some questions about virtual MIDI Drivers (twice), but eventually gave up on it, because I had been too inexperienced in driver programming (and probably still am) and because there was little help in form of actual source code. Well at the time, I just moved to the next best alternative which was Tobias Erichsen's virtualMIDI-Driver and SDK which did the job so far, however I now have developed a little Microcontroller Board that I want to use as MIDI device and I now need a mixture of a virtual and real MIDI driver. So back to the WDK... I now have been able to use the DMusUART and MPU401 adapter Sample to create an installable driver that frankly does nothing so far. I understand quite a bit of whats going on in the miniport part of the driver and stripped the DMusUART sample of most hardware related stuff. Where I'm stuck now is the part where the virtual Device ist started and the MIDI ports are created (i.e. the MIDI Pin of the miniport driver is connected to a resource i believe). As opposed to Tobias' virtualMIDI driver, i do not require dynamic creation of ports, so I added an interfaces section to my inf file: [vmidi.NTamd64.Interfaces] AddInterface=%KSCATEGORY_AUDIO%,%KSNAME_Wave%,vmidi.Wave AddInterface=%KSCATEGORY_RENDER%,%KSNAME_Wave%,vmidi.Wave AddInterface=%KSCATEGORY_CAPTURE%,%KSNAME_Wave%,vmidi.Wave [vmidi.Wave] AddReg=vmidi.Wave.AddReg [vmidi.Wave.AddReg] HKR,,CLSID,,%Proxy.CLSID% HKR,,FriendlyName,,"VMIDI Wave" And indeed DbgView shows that the system is calling the startDevice function of the adapterpart of the driver, however apparently the ResourceList is empty and therefore no Miniport is created. If i circumpass the if checking the ResourceList for entries, I create a bluescreen. MSDN again isn't too much help, some part are very well documented, others nearly not at all. Maybe you guys can bring me on the right track. Regards, Max