Hello, Please excuse the fact that I have had no formal training, and have learnt what I know of Windows programming as need has arisen. I have developed a DXi host, which connects to a sequencer such as Sonar or Cubase. To make the connection I use one "cable" from the host to the sequencer, and two "cables" from the sequencer to the host. I have studied the DDK and, based on the DMusUart and FMsynth examples, managed to create the required IMiniportMidi loop-back driver. All works well except that I would like to hide the "cable" ends that the host uses, such that they are not available to the sequencer (or any other application). I would be grateful for any suggestions as to how this may be achieved. Regards, Steve.