Running Unix v5 in SIMH
From Computer History Wiki
Version 5 only exists as an rk05 disk image, so this is pretty simple to get running.
First you'll need the disk image, it's in any TUHS mirror, and a direct link to the file here.
boot.ini
set cpu 11/45 att rk0 v5root boot rk0
Then boot it up something like this:
PDP-11 simulator V3.8-1 Disabling XQ @unix ;login: root #
You do have to tell the bootloader to boot the unix kernel.. and there is no password for the root user.