You'll probably want to get in touch with TyRaNiD. He had written up some notes on programming the CD interface. He sent them to me a while ago, but I think I lost them in an HD crash. I'll also check my own doc collection to see if I can find anything, but that probably only has SGL/BIOS info, and maybe some architectural notes on the capabilities of the reader. There should also be a thread lurking around somewhere in this board that describes how to trigger the security signature check, which could provide some valuable clues for BIOS/SGL reverse engineering, if it comes to that.
ExCyber, if you don't mind sharing your docs, please take a look at my list, I'd love to put up everything there is for download. (I remember we talked about this earlier before your move, but you had some computer trouble then.)