The SM-1420 was a PDP-11/34+

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...

 clone, and the successor to SM-4

SM-4

The SM-4 was a Polish PDP-11/40 computer 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...

 in Soviet Bloc countries. It was produced in the Soviet Union

Soviet Union

The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 and Bulgaria

Bulgaria

Bulgaria , officially the Republic of Bulgaria , is a parliamentary democracy within a unitary constitutional republic in Southeast Europe. The country borders Romania to the north, Serbia and Macedonia to the west, Greece and Turkey to the south, as well as the Black Sea to the east...

.

The standard package included 256KB

Kilobyte

The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...

 MOS memory, two RK-06 disks, 2xTU-10, CM-6315 barrel or DZM-180 dot-matrix printer, Mera 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...

 compatible or VTA-2000-15 (BTA 2000-15) VT100

VT100

The VT100 is a video terminal that was made by Digital Equipment Corporation . Its detailed attributes became the de facto standard for terminal emulators.-History:...

 compatible terminal

Computer terminal

A computer terminal is an electronic or electromechanical hardware device that is used for entering data into, and displaying data from, a computer or a computing system...

s. Some 1420s were produced by the UK company Quest Automation Plc.