I have to disagree with you on this one NeverHappy. I know for a fact that I read in numerous places that the RP-56 had the Faroudja "Sage" chip. I can't speak of any other models, but the RP-56 had the Sage chip. I remember this because at the time it was the cheapest DVD player to have this chip, and pretty much every review at the time mentioned that it was almost a steal to get this chip in a rather cheap DVD player.
Here's a review I found that mentions that. Scroll down for the RP-56.
Secrets of Theater review 
