Asterisk & Old Dialogic ISA Cards

Hi All

I am not sure if I will get an answer, but I have searched the web all over and could not find any answer. I have some old Dialogic D41 ISA cards that is still working and thought I could use them with Asterisk. As far as I could tell Asterisk do have channel drivers for Dialogic (According to Mark in a mail I saw dated 2003), but at a cost. Why is this ? I have tried this on GNU’s Bayonne and the cards works fine, without any licences. Why then do we need licecnes for Asterisk. Can I write you guys a channel driver for Asterisk, or is there hope at the end of the tunnel.

Kind Regards