DECSYSTEM-20

The DECSYSTEM-20 was a family of <a href="/facts/36-bit/P0V83YtM">36-bit</a> <a href="/facts/Digital_Equipment_Corporation/ztxs6keA">Digital Equipment Corporation</a> <a href="/facts/PDP-10/zlfam4wk">PDP-10</a> <a href="/facts/Mainframe_computer/nrBR6rWa">mainframe computers</a> running the <a href="/facts/TOPS-20/uBCxEqk9">TOPS-20</a> <a href="/facts/Operating_system/8XTuvMh2">operating system</a> and was introduced in 1977.
<a href="/facts/PDP-10/zlfam4wk">PDP-10</a> computers running the <a href="/facts/TOPS-10/FdKwlRK5">TOPS-10</a> operating system were labeled DECsystem-10 as a way of differentiating them from the <a href="/facts/PDP-11/9HkGUzFn">PDP-11</a>. Later on, those systems running TOPS-20 (on the KL10 PDP-10 processors) were labeled DECSYSTEM-20 (the block capitals being the result of a lawsuit brought against <a href="/facts/Digital_Equipment_Corporation/ztxs6keA">DEC</a> by <a href="/facts/Singer_Corporation/lFrnG7qa">Singer</a>, which made its own <a href="/facts/Singer_System_Ten/FmKGWvdh">System Ten</a> model, occasionally referenced in reporting as the "System 10"). The DECSYSTEM-20 was sometimes called PDP-20, although this designation was never used by DEC.

DECSYSTEM-20 open-in-new

DECSYSTEM-20