The SM-4 was a Polish

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

 PDP-11

PDP-11

The PDP-11 was a series of 16-bit minicomputers sold by Digital Equipment Corporation from 1970 into the 1990s, one of a succession of products in the PDP series. The PDP-11 replaced the PDP-8 in many real-time applications, although both product lines lived in parallel for more than 10 years...

/40 computer

Computer

A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...

 clone, in the second half of 1980s. It was very popular in science and technology.

The standard configuration included 128 or 256 KB core memory, tape puncher, two RK-05 removable 2.5 MB disks and two RK-05F fixed disks, two TU-10 drives and Videoton

Videoton (company)

Videoton is a privately owned Hungarian company, Contract Electronics Manufacturer , the largest independent Electronic Manufacturing Services provider in the CEE region, in TOP 30 worldwide, TOP 10 in EU according to the latest ranking of...

 VDT-340 terminals (VT52

VT52

The VT52 was a CRT-based computer terminal produced by Digital Equipment Corporation introduced in September, 1975 . It provided a screen of 24 rows and 80 columns of text and supported all 95 ASCII characters as well as 32 graphics characters. It supported asynchronous communication at baud rates...

 non-compatible).

The SM-series also included the SM-3, without floating point

Floating point

In computing, floating point describes a method of representing real numbers in a way that can support a wide range of values. Numbers are, in general, represented approximately to a fixed number of significant digits and scaled using an exponent. The base for the scaling is normally 2, 10 or 16...

 processing, similar to DEC's PDP 11/40 and 11/34 models. In early production, ferrite core memory was used.

Operating systems commonly used, included:

• RT-11
  RT-11
  RT-11 was a small, single-user real-time operating system for the Digital Equipment Corporation PDP-11 family of 16-bit computers...
  
   (Rafos after partial translation)
• RSTS/E
  RSTS/E
  RSTS is a multi-user time-sharing operating system, developed by Digital Equipment Corporation , for the PDP-11 series of 16-bit minicomputers. The first version of RSTS was implemented in 1970 by DEC software engineers that developed the TSS-8 time-sharing operating system for the PDP-8...
  
  
• RSX-11
  RSX-11
  RSX-11 is a family of real-time operating systems mainly for PDP-11 computers created by Digital Equipment Corporation , common in the late 1970s and early 1980s. RSX-11D first appeared on the PDP-11/40 in 1972...
  
  
• DSM-11 (DIAMS after partial translations)
• DEMOS
  DEMOS
  DEMOS was a Unix-like operating system developed in the Soviet Union...
  
   and MNOS
  MNOS
  MNOS was a Unix-like operating system developed in the Soviet Union. It was derived from Unix Version 6 and consequently heavily modified to incorporate many features of BSD Unix...
  
  

Similar models included the SM-1420

SM-1420

The SM-1420 was a PDP-11/34+ clone, and the successor to SM-4 in Soviet Bloc countries. It was produced in the Soviet Union and Bulgaria....

, with semiconductor memory, and the SM-1600, a hybrid of the SM-1420 and the M-6000(?), a system produced in Minsk

Minsk

- Ecological situation :The ecological situation is monitored by Republican Center of Radioactive and Environmental Control .During 2003–2008 the overall weight of contaminants increased from 186,000 to 247,400 tons. The change of gas as industrial fuel to mazut for financial reasons has worsened...

. The main producer was a Kiev

Kiev

Kiev or Kyiv is the capital and the largest city of Ukraine, located in the north central part of the country on the Dnieper River. The population as of the 2001 census was 2,611,300. However, higher numbers have been cited in the press....

-based factory in Ukraine

Ukraine

Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...

.