I was wondering when this might come to fruition. Enthusiasts are often willing to put up with a tremendous amount of inconvienience. I remind folks of this that the Altair 8800 (and IMSAI) were, in their base models, something you toggled in your machine code into directly. PDP-8's and PDP-11's had core but if you had corrupted memory you had to toggle in the boot loader to get them restarted.

On a whim I wrote a quick 'virtual machine' (which is to say an emulator) for the PDP-11 on an Arduino 328. It runs faster than a 'real' PDP-11/40 (on which it was modelled).

My thought was that you could pull a copy of 2.9BSD or V6 UNIX from the PUPS archive and build an equivalent of the same system Dennis and Ken developed C on pretty easily. Add a terminal and you're good to go. However, I recognize that if you're going to the trouble to do it you should really take advantage of modern gear.

I'm glad to see that these guys are taking that approach, Linux might be a bit heavyweight (you could do a much simpler and cheaper DOS like OS) but it does have the advantage of lots of available software.