most executed instructions were encoded in a single byte, the object code for Kronos was very compact. Although Kronos was a proprietary processor, it was well suited to 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 then a perfect language for this purpose, and Kronos was a perfect processor to effectively run the Modula-2 software. Hardware An advanced version of Kronos was based on a 32-bit stack-type КА1845ВМ1 processor, КА1845ВС1 data processing unit, and УУП memory control unit. All the three were designed and fabricated by КНИИМП, Kiev Research Institute of Microdevices. КА1845ВМ1 had 246 commands, which allowed supporting Modula-2 language. It also featured hardware support of interrupts and process synchronization. The CPU was fabricated in a 2.5 um CMOS technology with two layers of metallization and packaged in a planar 84-pin metal-polymer case. It contains 199 thousands elements and has area of 8.55x8.1 mm^2. The maximum clock frequency is 10 MHz. КА1845ВС1 contained ALU, 8x32 stack, matrix shifter, 16x32 register block, and status flag multiplexers. The amount of addressable memory is 4 GB. The chip area is 5.8x5.25 mm^2, 16 thousand elements. УУП provided operation with virtual memory up to 4 GB. It contains a data cache (128x32), a redirect buffer (128x40), a dynamic RAM controller, and an error detection and correction circuit. Memory access time does nor exceed 100 ns. УУП chip contains 102 thousands elements and has area of 9.1x7.3 mm^2. Software The Kronos software included: Versions of the proprietary operating system Excelsior Compilers for Modula-2, C, and Fortran CAD systems Other applications Operating system The Kronos workstation includes an operating system named Excelsior, developed by the Kronos Research Group (KRG). It is a single user system based on Modula-2 modules. In design, it is similar to the OS Medos-2, developed for the Lilith workstation, at ETH Zurich, by Svend Erik Knudsen with advice from Niklaus Wirth. References External links , history in Russian The Kronos Research Group recovered from Internet Archive A Brief History of Modula and Lilith Acquisition of a Kronos workstation and more by the National Museum of Science and Industry in London Historical source code from Kronos 198x USSR 32-bit workstation Emulator for the Kronos workstation (via Internet Archive) runs on Windows-NT; tested thereon successfully. Two logins