Hi,

In a recent repair, I could confirm that Splice Byte XD-300 is completely a Fidelity Chess Challenger 7 clone: Apart from the hardware, the ROM content are identical bitwise.

I mention this in case you want to add it to the Wiki:
Splice

I apologize for writing in English, since I don't know German.

Regards,
Gerardo M. (aka Berger)