I recently bought a new boat (new too me) that came with two HDS9's. I want to be able to power'em up in the house and get familiar with them. On my hummingbird, I had a cable that I could hook into my RadioShack power supply and coould run the bird in simulation mode ... I'm sure that is doable with this as well. Can someone tell me how to do that? Is there another auxilary cable I need to buy? Thanks in advance for the help...