I thought I'd might be able to tie into the ports on the second EFIS but wasn't really sure. I'll try to get ahold of GRT and have them explain to me how these various components talk to each other at what times.
That would explain where a fifth port would come in on a Sport. I currently don't have the upgraded processor.
Thanks guys, thats what I was looking for - options. I'll go ahead and get the wires and antennas now to get that part taken care of.
I have been emailing with Mark at GRT.
RV-9A - finishing tasks
painting - maybe it will fly in 2013