SM-4
Template:For {{#invoke:other uses|otheruses}} The SM-4 (CM-4) is a PDP-11/40 compatible system, manufactured in the Eastern Bloc in the 1980s. It was very popular in science and technology.Template:Citation needed They were manufactured in the Soviet Union, Bulgaria and HungaryTemplate:Citation needed, beginning in 1975.<ref name="cold">Template:Cite book</ref>
The standard configuration includes 128 or 256 KB core memory,<ref name="cold"/> tape puncher, two RK-05 removable 2.5 MB disks and two RK-05F fixed disks, two TU-10 drives and Videoton VDT-340 terminals (VT52 non-compatible). The SM-4 processor operates at 900,000 operations per second.<ref>Template:Cite book</ref>
The SM-series also includes the SM-3. The SM-3 lacks floating point processing, similar to DEC's PDP 11/40 and 11/34 models. In early production, ferrite core memory is used. It operates at 200,000 operations per second in register-to-register operation.<ref name="advances"/>
Operating systems commonly used include:
- RT-11 (Rafos after partial translation)<ref>Template:Cite book</ref>
- RSTS/E
- RSX-11
- DSM-11 (DIAMS after partial translations)
- DEMOS and MNOS
The SM-4 was manufactured in seven configurations, numbers SM-1401 through SM-1407.<ref name="advances"/>
Similar models include the SM-1420, with semiconductor memory, and the SM-1600, a hybrid of the SM-1420 and the M-6000, a system produced in Minsk.Template:Citation needed
The main producer of the SM-4 was Minpribor, at a facility in Kyiv, Ukraine, which began production in 1980.<ref name="advances">Template:Cite book</ref>