OK folks, I upgraded a bit from what I have for a fish finder to a still older unit someone else had who upgraded to a newer unit. I have now got a Hummingbird 797 Side imaging unit. I hooked it up to my battery to check it out, but can't get past the set up screens. I would think it would have like a demo screen to show what it's capable of. It did not come with any sd card at all. I guess my question is, does it need an sd card to get past these set up screens? And if so, does it have to be a certain type of card, i.e. a hummingbird specific card?? Thank you all for the help ahead of time. Jamesdean, aka Eric.