Robotron K 1820
The K 1820 was a workstation developed in East Germany. Its more exact name was "RVS (computer system with virtual memory) K 1820" and its cipher in the SM EVM of the former COMECON countries was "SM 1720". VEB Robotron Elektronik Dresden began development of the K 1820 in 1986 and it went into serial production in 1990.
The K 1820 was a clone of the MicroVAX II made by Digital Equipment Corporation (DEC). The import of western 32-bit computers to the COMECON area was impeded by the CoCom technology embargo. Moreover, the MicroVAX II CPU was one of the first semiconductor devices which was protected by the Semiconductor Chip Protection Act of 1984. Therefore, independent development of modern CAD technology based on a 32-bit computer architecture was required. Copies of the MicroVAX II were also created in Hungary (MicroSTAR 32 or TPA-11/510)  and the Soviet Union (SМ 1702).
The K 1820 extended the VAX-compatible computer line in the SM EVM and the models of the K 1820 achieved approximately 90% of the performance of the K 1840 (Robotron "RVS K 1840", compatible with the VAX 11/780). The K 1820 was fully compatible with K 1840 software, so preexisting system and application software could be used.
The K 1820 is based on the VLSI U80700-microprocessor system, its 32-bit CPU U80701 was developed according to the MicroVAX 78032. The Mainboard design and construction were original. A VT220-compatible terminal, the K 8941, was developed for the machine.
Approximately 10 K 1820 prototypes were built up to 1990. In the middle of 1990 development was stopped, because economic production was not possible under free-market conditions after the monetary, economic and social union between East and West Germany on 1 July 1990. Subsequent to this Robotron's traditional markets in the Soviet Union and eastern Europe collapsed.
At least one prototype of the K 1820 is owned by the Technical Collections Dresden.
- Dieter Walter: History of the VEB Robotron Elektronik Dresden; PDF in German language
- Claus Preussler, Klaus-Dieter Weise: Compilation of Robotron computer products; PDF in German language
- User's manual K 1821/K 1822. VEB Robotron Elektronik Dresden, November, 1989
- Technical manual ZVE KAC20. VEB Robotron Elektronik Dresden, December, 1989