The Setun 70 emulator, developed in Rust, replicates the architecture of the Soviet ternary computer. The project aims to provide a platform for users to study the machine's unique design and write programs for it. The development process has been ongoing since 2001, utilizing various programming languages before settling on Rust.
The Setun 70 is a stack-based machine using balanced ternary logic with digits -1, 0, and +1. Its memory consists of 729 words, where only 243 are programmable, while the rest are reserved for ROM. The system supports external storage via two magnetic drums, each with a capacity of 19.5 megatrits, and peripheral devices like paper tape readers and Consul 254 typewriters.
The computer's instruction set includes 81 commands, divided into basic operations, system commands, and 27 macro-operations stored in ROM. The machine supported advanced software, including text editors, assemblers, and the Nastavnik automated learning system used at Moscow State University. The emulator specifically targets the 1970 base architecture.
The developer notes that the Setun 70 existed in two versions: the original 1970 model with a single data stack and a 1975 modification designed for structured programming. The emulator addresses the challenges of mapping ternary logic onto modern binary systems, focusing on efficient data representation and memory management within the constraints of the original hardware.
