I have looked at the 877 datasheet, but I only see how to configure RA3 as Vref+. They don't ever explain what this means!? Does this mean that All your other A/D inputs can't exceed Vref or what? Is this done is software or something. How do you set it up, and what implications does it have? Thanks, Brandon -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.