It sends midi data to my computer, and without FPC, hitting a kick would trigger a C and hitting a snare would trigger a C#, to continue my previous example. I have a yamaha dtx 500 midi drum kit at my house right now that belongs to a friend who is a drummer. So for example, if you played a 'C' on your keyboard, it would play whatever you map to the 'C' pad, for example a kick., and if you play a C#, it will play whatever you map to C#, so for example, a snare. What FPC does is it converts midi data for notes (A, A#, B) to samples (the pads). The main reason to use FPC is to link it to a real life piece of hardware. There is some false info being dished out in this thread.
