Setun (Russian: Се́тунь) was a balanced ternary computer developed in 1958 at Moscow State University. The device was built under the lead of Sergei Sobolev and Nikolay Brusentsov. It was the only modern ternary computer, using three-valued ternary logic instead of two-valued binary logic prevalent in computers before and after Setun's conception. The computer was built to fulfill the needs of the Moscow State University and was manufactured at the Kazan Mathematical plant. Fifty computers were built and production was then halted in 1965. In the period between 1965 and 1970, a regular binary computer was then 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 ternary computer, the Setun-70, was designed. The computer was named after the Setun River, which ends near Moscow University.