In 1984, the Kronos Research Group was founded by four students of the Novosibirsk State University, two from the Mathematical Department and two from the Physics Department. At that time the main objective was to build home computers for the KRG members. In 1985, the group joined the Russian fifth generation computerproject START, in which Kronos became a platform for developing modular multiprocessor reconfigurable systems MARS and played a leading role in the development of the first Russian full 32-bit workstation and its software. During 7 years the group designed and implemented:
Kronos 2.1 and Kronos 2.2 - 32-bit processor boards for DEC LSI-11
Kronos 2.5 - 32-bit processor board for Labtam computers
Kronos 2.6 - 32-bit workstation
The project START was finished in 1988. During the post-START years, a number of Russian industrial organizations had expressed interest in continuing the Kronos development and some had been involved into facilitating the construction of Kronos and MARS prototypes, including the design of a Kronos-on-chip. Nevertheless, changing in funding levels and the overall economic situation during perestroika did not allow those plans to be realized.
Architecture
Instruction set design was based on Niklaus Wirth's Modula-2 workstation Lilith, developed at the Swiss Federal Institute of Technology of Zurich, which in turn was inspired by the legendary Alto developed at Xerox PARC. The Modula-2-based Kronos was quite amenable to the basic principles of MARS, as Modula-2 is fundamentally modular, allowing programs to be partitioned into units with relatively well defined interfaces. These interfaces supported separate compilation of modules and separation of the module specifications from their implementation. The primary difference between Lilith and Kronos was that the latter was a 32-bit processor, compared with 16-bit Lilith, and Kronos incorporated a number of extensions to the instruction set to accommodate the inter-processor communication necessary in MARS. Kronos satisfied many aspects of the RISC design, although it was not pure RISC: the evaluation stack was used to evaluate expressions and to hold parameters for procedure calls. Since most of executed instructions were encoded in a single byte, the object code for Kronos was very compact. Although Kronos was a proprietary processor, it was nicely suited to the applications which were sensitive to high programmability rather than to software compatibility. For example, embedded control systems require fast and reliable design of new original applications for controlling unique objects and processes. Modula-2 was a perfect language at that time for this purpose, and Kronos was a perfect processor to effectively run the Modula-2 software. The Kronos software included:
