thought I'd share this info that I found.

An Amici prism is much like a prism star diagonal, except that its hypotenuse, rather than being flat, is
ground into 2 faces forming a 90 degree roof. A light ray from the telescope enters the front face nearly
flat-on, bounces off one face of the roof, then bounces off the other face of the roof, then exits the top
face. The Amici prism diverts the beam by 90 degrees while turning it right side up and correct
left-to-right.

A Schmidt prism (which many people have been incorrectly calling Amici) turns the beam through 45 degrees
while turning it right side up and correcting it left-to-right. Conceptually, take an Amici prism and deform
it by pushing its top face down to the 45 degree angle, while the ridge of the roof splits the difference,
becoming slanted by 22.5 degrees. In operation, the light enters the front face of the prism, bounces off the
top/back face, bounces off one side of the roof, bounces off the other side of the roof, bounces off the front
face, and exits the top/back face.

Heres how P+S Technik does it.

http://www.pstechnik.de/sheets/downloads/pp-dec12.pdf

On initial iewing of the PRO35 article, I could not find a technical description to match the diagrams but my german is far too poor to find it in any event.

(Some text originally here relating to patent techs deleted by myself until some checks are made.)