Cross-talk square-wave?

[Noel Chiappa]

I should mention that this is a pre-prototype; the final thing won't have a
cable at all; so this isn't a fundamental issue with the design (if it is
cross-talk). And the SD card isn't even plugged in when we see this - if it is
cross-talk, it has to be some other signal carried in the cable.

We're just trying to figure out how cross-talk can possibly produce an induced
square-wave.

	Noel