Ersatz-11
From Computer History Wiki
Ersatz-11 is a simulator for the PDP-11; it runs under either Windows, Linux, MS-DOS, OS/2, or directly on PC hardware.
Although it is principally oriented toward commercial use (for users who want to migrate existing applications from aging PDP-11 hardware), there is a free 'Demo' version, which may be used for unlimited personal/hobby use.
It supports a very wide range of simulated disks, tapes, serial lines, etc; note that the Demo version does not support DH11's (although the full commercial version does).
