As the author of both LSX and Mini-UNIX, I would suggest that the LSX source code is a better starting point for the 11/04, especially if single-user is the target. Mini-UNIX was written to support a small number of users on the PDP 11/10 without an MMU. However, I'm not current on what sources are still available. Heinz On 7/30/2020 9:13 AM, Warner Losh wrote: > On Thu, Jul 30, 2020 at 7:49 AM Noel Chiappa > wrote: > > - If you get the V1 that ran on an -11/20 (which is mostly > compatible with > the /04 and /05), it should run on an /04. (Not sure what you'd > use for mass > storage, on a physical /04, though.) I'm not sure when they > dropped the /20 - > I think V4 n(at the latest)? But V2 and V3 are lost. > > > Yes, the reconstructed 1st edition may run (though from dates and > such, it's somewhere between 1st and 2nd edition), though I've no > direct experience with 11/04 hardware, nor ideas on how to bootstrap > it onto appropriate physical media... > > I have it in my head that the 4th edition was rewritten for the 11/45 > and removed support for 11/20. I thought I knew why, but could only > find part of the story in the manuals... > > There's a strong note in the 4th edition preface that it applies only > to the 'c' version of Unix and the 3rd edition preface has a > note saying the manual doesn't apply to the 11/20 version and to look > in the 2nd or even 1st edition manuals for that. > > As others have mentioned, Mini-unix and/or LSX might have a shot, but > it might be best characterized as a long shot. > > Warner