Does somebody know something about these two devices from KDS?
I've collected some (conflicting) info about both devices in the internet.
Some info fragments about the "KDS Communicator 104" are here, http://cpcwiki.eu/index.php/KDS_Communicator_104 it might be either a Modem... or a serial parallel interface... or both bundled together...?
And the "KDS Interface for the Amstrad"... I've collected some info on the bottom of the http://cpcwiki.eu/index.php/KDS_Electronics page. "Interface" could mean almost anything. Externally it looks a lot like the KDS 8bit printer port, although the 8bit port photo doesn't show that small cable.