Russians build balanced ternary computer in 1958 [1] and were experimenting improving its design up until early 1970-th. [1] https://en.wikipedia.org/wiki/Setu

Russians build balanced ternary computer in 1958 [1] and were experimenting improving its design up until early 1970-th. [1] https://en.wikipedia.org/wiki/Setun https://en.wikipedia.org/wiki/Setun