The earliest versions of the very first c compiler known to exist in the wild written by the late legend himself dmr.
These are not capable of being compiled today with modern c compilers like gcc. I am only posting these here for the enjoyment and reminiscing of the spark that ignited a soon to be trillion dollar industry. Enjoy. :)
You guys might be able to play around building this compilier with Aiju's pdp-11/unix emulator. I havent tried building this myself so I cant confirm it works, but I posted the link to her emulator for anybody wanting to hack around with it.
PDP-11 Emulator: [http://pdp11.aiju.de/] (so i've been playing around with this to see if it still works, and it clearly has problems right now. if somebody wants to try and create like a VM image of unix running on PDP-7 hardware, id happily link to it here.)