There is a manual from Moon/Stallman/Weinreb: Lisp Machine Window System:

http://bitsavers.informatik.uni-stuttgart.de/pdf/mit/cadr/LI...

> CADR Lisp Machine window system. (Not to be confused with Genera!!!

Early Genera was based on the Lisp Machine window system. Later Symbolics introduced a new window system (Dynamic Windows), but the old one (TV, ...) was still provided.