s/DNS/DNA/ - dyslexia sucks.... On Thu, Apr 6, 2017 at 2:02 PM, Clem Cole wrote: > ​try-II sorry about that...​ > > > On Wed, Apr 5, 2017 at 9:18 PM, Wesley Parish > wrote: > >> The mention of UNOS a realtime "clone" of Unix in a recent thread raises >> a question for me. How many >> Unix clones are there? >> > > ​An interesting question.... I'll take a shot at this in a second, note > there is a Wikipedia page: https://en.wikipedia.org/wiki/Category:Unix_ > variants that I don't fully agree with. > > The problem with all of this question is really depends where you place > which boundary on the following continuum: > > non-unix add-unix ideas trying to be > unix might as well be unix research unix > stream > > eg VMS eg Domain eg UNOS > eg Sys V, BSD/386 & Linux Vx & BSD VAX > > > Different people value different things. So here is my take from the > "cloned" systems I used/was basically aware.... > > Idris was a V6 clone for the PDP-11, which I saw 1978ish. I can say I > was able to recompile code from v6 and it "just worked" so from a user's > standpoint it might as well has been. But the compilers and assemblers > were different and I never tried anything "hard" > > The first attempt to "clone" v7 that I knew about was in France, and > written in Pascal - I think at Ecole Tech in Paris? The name of the > project escapes me, but they presented the work in the 1979/80 winter > USENIX (Blackhole) conference in Denver. There were no proceedings in > those days. I believe it also ran on the PDP-11, but I never ran it so; so > I have no idea how easy it was to move things from Seventh Edition. But I > also don't think they were working binary compatibility, so I think it > landed more toward the center. > > The Cruds folks (Goldberg) wrote UNOS shortly there after (early 80s) > It was definitely not UNIX although it tried to have be mostly. We had > CRDS box at Masscomp and before I arrived they plan had been to use it get > code working before the RTU was running. But the truth was it failed > because it was not UNIX. The 68000 vs Vax issues were far, far less of an > issue than UNOS != UNIX. To Goldberg's credit, he did have a couple of > cool things in it. I believe only system commercial systems that used > Kanodia & Reed's Sequences and Eventcounts, were UNOS, Apollo Doman, and > Stellar's Stellix (I'm not sure about DG - they might have also at one > point). But these were hidden in the kernel. Also the driver model he > had was different, so there was no gain writing drivers there. > > Mike Malcom & Dave Cheriton at Waterloo developed Thoth (Thoth - Thucks), > which was written in B, IIRC. Ran on the PDP-11 and was very fast and > light. It was the first "ukernel" UNIX-like/clone system.. Moving code > from V7 was pretty simple and there was attempt to make it good enough to > make it easy to move things, but it was not trying to be UNIX so it was > somewhere in the middle. > > The Tunis folks seem to have been next. This was more in the left side > of the page than the right. I think they did make run on the PDP-11, but > I'm not so sure how easy it was to move code. If you used their > concurrent Pascal, I suspect that code moved. But I'm not sure how easy it > was to move a raw K&R "White Book" C code. > > CMU's Accent (which was redo of Rochester's RIG) came around the same > time. Like Tunis the system language was an extended Pascal and in fact > the target was the triple drip Perq (aka the Pascalto). The C compiler > for it was late, and moving code was difficult, the UNIX influence was > clear. > > Apollo's Aegis/Domain really came next - about 82/83 ish. Like Accent it > was written in hacked up Pascal and the command were in Ratfor/Fortran > (from the SW Tool User's Group). C showed up reasonably early, but the > focus did not start trying to be UNIX. In fact, they were very > successfully and were getting ISV's to abandon VMS for them at a very good > clip. UNIX clearly influenced the system, but it was not trying to be > UNIX, although moving code from BSD or V7 could be done fairly easily. > > Tannebaum then did MINIX. Other than 8086 vs PDP-11-ism, it was a pretty > darned good clone. You could recompile and most things pretty much "just > worked." He did not support ptrace and few other calls, but as a basic V7 > system running on a pure PDP PC, it was remarkably clean. It also had a > large number of languages and it was a great teaching system - which is > what Andy created it be. A problem was that UNIX had moved on by the > time Andy released it. So BSD & V8 were now pretty much the definition of > "UNIX" - large address spaces were needed. As were the BSD tools > extensions, such as vi, csh. Also UUCP was now very much in the thing, > and while it was a pure v7 clone, it was the lack of "tools" that made it > not a good system to "use" and it's deficiencies out weighed the value. > Plus as discussed elsewhere, BSD/386 would appear. > > Steve Ward's crew at MIT created TRIX, which was a UNIX-like, although > instead of everything being a file, everything was a process. This was > supposed to be the system that rms was originally going to use for GNU, but > I never knew what happened. Noel might. I thought it was a cool system, > although it was a mono-kernel and around this time, most of the OS research > had gone ukernel happy. > > Coherent was announcement and its provenance is questioned, although as > discussed was eventually released from the AT&T official inquiry and you > can look it your self. It was clearly a V7 clone for the PC and was more > complete than Minix. I also think they supported the 386 fairly quickly, > which may have made it more interesting from a commercial standpoint. It > also had more of the BSD tools available than Minix did when it was first > released. > > CMU rewrites Accent to create Mach, but this time splices the BSD kernel > inside of it so that the 4.1BSD binaries "just work." So it's bit UNIX > and a new system all in one. So which is it? This system would begat > OSF/1 and eventually become Apple's Mac OS? I think its UNIX, but one can > claim its not either.... > > By this point in time the explosion occurs. You have Lion's book, Andy's > and Maury Bach's book on the street. he genie is clearly out of the bottle, > and there is a ton of code out there and the DNS is getting all mixed up. > Doug Comer does Xinu, Sheraton does V-kernel, Thoth is rewritten to become > QNX, and a host of others I have not repeated. BSD's CSRG group would > break up, BSDi would be created and their 386 code come out. It was > clearly "might as well be" if it was not. Soon, Linus would start with > Minix and the rest is history on the generic line. > > Clem > > -------------- next part -------------- An HTML attachment was scrubbed... URL: