I created a thread on AVS Forums with a sample file attached as a download for the MX-890 and MX-780.

You can use that file to get some idea of what a working system looks like and then can either modify that one to work with your setup or create a new file on your own.

I'm not a pro but after having a bad experience with one, I decided like you that it would be better to do it on my own and learn how this stuff works. Teach yourself to fish, and all that jazz.

Here's the thread: [Link: avsforum.com]

The download file is in the first post and will auto-install the example file and graphics. You can ask any questions on there if you want -- other DIY guys can help out also.

Good luck!