For OS X, we are using the CoreMIDI system that Apple has built into it's operating system which most DAW's support now. CoreMIDI publishes patch lists using the ".xml" format.

In your /Library/Audio/MIDI Devices/MOTU folder, you will see a series of .middev and .midnam files which serve as the patch names for the devices we have included support for in DP4.

Included in DP4, in the MOTU DP4 Folder > Extras folder, you will see an application called "Expansion Board Setup." This application will allow you to assign supported expansion boards to devices you have already added in the Apple Core Application, Audio MIDI Setup. These patches will then publish into DP4.

For deeper MIDI editing, check out Unisyn, our MIDI Editor/Librarian.