Before we have a look at the FSBUS hardware itself, let's begin with an architectural view on the system. On top of all there is the well known flightsim. The world renowned fsuipc DLL is used to interface the many controls in flightsim. This DLL is frequently used by many 3rd party software and so does FSBUS use this valuable piece of software.
The FSBUS DLL is a fix library of functions which capsulates all the nifty parts of dealing with hardware bits and pieces. It is an "easy to use" interface for your individual cockpit software. This individual Cockpit Executable is to be developed by your own. Your sourcecode must be compiled with Visual Studio or other compilers.