[googamooga]

Ternary logic based computer Setun with 9-bit "bytes" was developed in late fifties in the USSR. Not much info on about it in English, unfortunately.

https://en.wikipedia.org/wiki/Setun

[buescher]

Ternary on binary systems usually uses a 2-bit "trit" with an extra potential state. That's even how the later Setun machines did it, from what I understand. Oh yes, and the Soviets even developed their own trinary Forth dialect for them.

[kragen]

Even the original Setun machine worked that way, as it turned out, if we believe Willis Ware's contemporary report on Soviet computers.