Ok, some oscilloscope shots and the big pile of CSV and VCD files I collected are on a new page on my Wiki:
Pin 11 definitely appears to be some type of sync pulse, and Pin 10 appears to be data in the sync pulse. As best as I can tell from my Tektronix T912 (yes, it’s as old as I am!) both Pin 11 and Pin 10 are normal square wave signals, but are at the end of the range of my 10Mhz scope.
I think the Saleae (Logic 16) may have problems with these signals, as they do not appear to go high on my scope when the Saleae reported them high, but my scope recorded nice waveforms where the Saleae only reported glitches in the data portion.