Uns Fms
Forget the manual and the software simulator. I tried both, before I played with the actual box in the plane, and found the manual and the software simulator (at FlightSafety) confusing and difficult to understand. Then I got in the plane with the UNS-1C and found it a snap to use, very intuitively easy, at least for most of the functions. (And it was the first time I used a FMC or FMS.) So just play with it in the plane for a bit. Have someone show you how to enter a flight plan (much easier than something like a GNS 430/530), then hit the NAV button; select the FMS as the NAV source for your HSI and you are set. When you get to altitude, put the thing on autopilot, have the other guy watch out the window, then just play with the buttons and see what is in there and what it does. (Probably should put the plane in HDG Hold rather than NAV while you do this.) You'll be able to do most of the stuff you need to do with it after 2 or 3 flights. THEN dig out the manual for the more advanced stuff, and it'll make more sense. I've been flying the UNS-1C (recently upgraded to a UNS-1C+) in a King Air for almost 4 years and it is fantastic. Wish I had one in the other airplanes I fly.