Wikipedia
DECsystem
DECsystem was a line of server computers from Digital Equipment Corporation. They were based on MIPS architecture processors and ran DEC's version of the UNIX operating system, called Ultrix. They ranged in size from workstation-style desktop enclosures to large pedestal cabinets.
The DECSYSTEM name was also used for later models of the PDP-10, namely the DECSYSTEM-10 and DECSYSTEM-20 series.