Discussing 'non-standard byte sizes' with co-workers today, one mentioned hearing of soviet experiments with computers that used three-state bytes - and not just what is common today, 0, 1 and High Impedance meaning "absent on the bus", but actual trinary system, where the bits could achieve three logical values. Unfortunately, he was unable to provide any more details - nothing beyond "hearing about it."
Could someone provide more detail? Was there a computer system that was based on the trinary system? What was it? How did it work?