Each company has their own special software packages and interface cables. See the appropriate dealers.
If you are interested in Mercury's diagnosic tools, you cannot use their software for more than 30 days. Only dealers can renew the software licensing.
You are in luck, though, CDI electronics makes their own special Mercury software package and cable, with Yamaha capabilities coming soon. Here is a link to an article about it:
http://www.bwbmag.com/output.cfm?id=1570393