I've finished the schematic of my MSX-MUSIC adaptor for the Sega Master System, and put it online. There's a short description of it in the S8 dev forum (third post!) and I've included the direct link here also.
http://www.smspower.org/dev/forum/index.shtml and http://student.cusu.cam.ac.uk/~rga24/computer/projects/adaptor.pdf Comments / bugfixes / suggestions welcome. Richard -- For info, see http://www.stack.nl/~wynke/MSX/listinfo.html