[TUHS] Unix for PDP11/20 w/o mmu or paging option

[Roland]

Hi Warner,
Thanks for your reply!

V5 is the earliest Unix we have contemporary images from. We have fragments from everything else earlier, including files scavenged/recovered from early DECtapes and some code recovered from kernel listings from a Unix course that was put together by Bell Labs...
What I foundon Wikipedia about Unix V5 is that is needs an MMU. " 5th Edition Targetedthe PDP-11/40 and other 11 models with 18 bit addresses." Because it uses18 bit address space it probably expects 248K of memory. My machine does nothave a paging option or mmu. So I think that means that I can't use V5 unfortunately...


The Unix 1972 project that some TUHS members did. I think it's in the TUHS distribution archive, but also on github. I think Warren Toomey's repo is the canonical one https://github.com/DoctorWkt/unix-jun72 but https://github.com/c3x04/Unix-1st-Edition-jun72 has a couple of newer fixes for a docker file to contain the simh simulator. I'm unsure what hardware that's supported, though.  The machine file suggests:
rk03/rk11   177400     disk             RK
dc11        174000     tty?             (not supp?)
tc11/tu56   177340     dec tape         DTn (not showing up in simh?)
rf11/rs11   177460     fixed head disk  RF
kw11-l      177546     clock            CLK
pc11        177550     paper tape       PTR/PTP
asr-33      177560     tty?             TTI, TTO

which has an RK03, not sure how close that is to an RK05, so some tweaks may be needed.
That RK03 isa Diablo 31. It uses the same packs and same interface as the RK05 and is 100%compatible. The RK05 was build by Digital itself and not by Diablo any more. I have the TC11/TU56, PC11, asr33 tty and KW11-L line clock as well. So that is almost the complete list of devices you showed here...


So if it is possible to generate a RK03/RK05 disk image from that simulator then I think I can put that on a real RK05 disk pack. But I'm completely new in this old Unix era... So if anyone could help to generate such an image then it would be a great help!
Regards, Roland
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