When I first built up the XOR and XNOR gates I used the rather naive method of just copying the method used in binary of stringing together NOR gates in particular patterns. This worked just fine but totally neglected the greater flexibility inherent in ternary circuits. I worked out on paper, and just tested on the board, an XOR that is reduced from 6 comparators to only 2 comparators as well as an XNOR that is reduced from 8 comparators to just 2 comparators. They both make heavy use of wired logic to make that possible. I also changed them to use LM319's for the sake of consistency. The previous versions of XOR and XNOR used 393's.

I'm pretty jazzed about this because I'm starting to have visions of single board ternary ALU slices. Lot's more work to be done before anything like that happens though.

The schematics are here and here.