One of the nicest things about porting Nestopia, speaking with the I've ported far too many emulators to have any sanity left
hat on is that Marty doesn't change the port API every release. The 1.2.4 code dropped straight into my Mac project half an hour ago with only a few minor compiler issues. I'm going to do a release in a few moments. Additionally, the core code is very clean (the Mac port is only about 300 lines of bridge to my shell).
You could probably do it in an evening, RB -- and yes, that is a challenge