Well, that was easy enough.
The SDM developers asked me to contact them on sdm_support AT btinternet DOT com.
I also noticed that in the User Manual provided with the ASSIST download, they say :-
"SDM is only possible because of the work done by CHDK developers, those who 'port' cameras to
CHDK, the developers of MagicLantern, members of the CHDK Forum and those who test SDM.
Many contributors use 'Internet id's' rather than their real names, the main contributions relevant to SDM
are :-
EWAVR/Damir Vrancic - using usb switch for synchronised shooting
vnd - precision synchronisation for more recent cameras
MagicLantern/srsa_4c/funnel - information that indirectly led to video sync 'solution'.
Friendly CHDK developers philmoz,srsa_4c and reyalp have provided invaluable advice."
greetings
Zweistein