Thanks for the link, as it seems to get a bit deeper into the way it worked, not just why.
DSSP was not invented. It was found. That is why DSSP has not versions, but only extensions.
Hmm. Why do I get the feeling it was rediscovered as Joy and lives on as Factor
There’s some exploration of them for Quantum Dots. That’s really esoteric. I did find something more people will understand: NAND, NOR, and SRAM done in ternary logic at 180nm.
Also found a ternary, content-addressable memory:
There’s an old ternary computer emulator, if you’re curious: http://tunguska.sourceforge.net/about.html
An interesting exercise is to come up with a universal gate for ternary logic. I believe this is a solution. (Edit: looked it up, turns out not to be that hard.)
Oddly enough, building the constants (from unknown wire signals) in a one-gate system seems to be difficult and I’m not sure if it’s possible. For a contrast, it’s trivial in binary logic because NAND(x, x) = NOT(x) and NAND(x, NOT(x)) = 1.