@BrennanKMN Thanks. Bummer; Stargazer/ZBox works okay (I've done a LOT of tweaking of settings and it's about as close to ZO as you can get it with a mechanical linkage). But my PP has been acting up lately (losing GPS signal, screen going spastic) and if it dies, I don't want to spend $1,500 for what I have now. I really don't need a re-power (engine has 1,200hrs on it--my last GT40 had 1,800hrs and would probably go 3,000 before a rebuild). I don't know if I'll still be skiing in 15 years, so have to look at the investment. Don't ski that many tournaments anymore, but instead of $1,500 for a new PP, I'd pay a few $k more if there was a way to TBW a GT40 and replace with ZO. Guess not, so better figure out what's going on with my PP. Thanks for the explanation.