DECSYSTEM-20

The DECSYSTEM-20 was a family of 36-bit Digital Equipment Corporation PDP-10 mainframe computers running the TOPS-20 operating system and was introduced in 1977.

The following models were produced: The only significant difference the user could see between a DECsystem-10 and a DECSYSTEM-20 was the operating system and the color of the paint.

A model 2060, for example, could typically host up to 40 to 60 simultaneous users before exhibiting noticeably delayed response time.

The Living Computer Museum of Seattle, Washington, maintained a 2065 running TOPS-10, which was available to interested parties via SSH upon registration (at no cost) at their website.

The first ever email spam message on 1 May 1978 was an advertisement for west coast users of the ARPANET to come see a DECSYSTEM-20.

DECSYSTEM-2020 front panel
2 DECSYSTEM-2020 KS-10s (1979) at the Living Computer Museum
Introduction and Reference Card for the DECSYSTEM-20 at Columbia University, 1980. The DECSYSTEM-20 was the mainstay of computing at Columbia from 1977 through 1988. [ 2 ]
University College of North Wales 1987 "..teaching work is carried out on the DEC 2020.."