Setun was a computer developed in 1958 at Moscow State University. It was built under the leadership of Sergei Sobolev and Nikolay Brusentsov. It was the most modern ternary computer, using the balanced ternary numeral system and three-valued ternary logic instead of the two-valued binary logic prevalent in other computers. The computer was built to fulfill the needs of Moscow State University. It was manufactured at the Kazan Mathematical plant. Fifty computers were built from 1959 and production was halted in 1965. Between 1965 and 1970, a regular binary computer was used at Moscow State University to replace it. Although this replacement binary computer performed equally well, it was 2.5 times the cost of the Setun. In 1970, a new model of the ternary computer, the Setun-70, was developed.
Setun was named after the Setun River, which ends near Moscow University.