Hello Robert,

Here the info of the Chess Proffesor, it's made by Newcrast Technologies same as the Super Enterprise, Sphinx and CXG are the same company
Newrast is stopped arrond 1990, The program of the Proffesor is from Frans Morsch and build in +- 1989, The Enterprise is build in 1986 and is from Kaare Danielsen . Kaare was discouverd by(on a special market in Brussel) Jan Louwan and he helped him on the way,Kaare programed on his little room in Danmark Jan did the testingwork,However the company did build computers with Kaare programs in it, but for commercial reasons the company said the program was from Julian Kaplan ,because he was much more famous as Kaare .technical info of the Chess Proffesor: 6301/16 Kb Rom/256Kbyte Ram/2MHz
So it's not a clone Robert.
The info is from Hein Veldhuis en Rob van Son.

Best regards,
Hans