From mboxrd@z Thu Jan 1 00:00:00 1970 From: clemc@ccc.com (Clement T. Cole) Date: Mon, 4 Jul 2016 17:12:21 -0400 Subject: [TUHS] OS for IBM PC (was: Algol68 vs. C at Bell Labs) In-Reply-To: <20160704181330.GM13274@mcvoy.com> References: <1467651263.29756.for-standards-violators@oclsc.org> <20160704181330.GM13274@mcvoy.com> Message-ID: <7A53ECB0-4C55-49F0-B785-CCB3BF7D0BFF@ccc.com> Thoth Thucks .... Actually to give Mike Malcom created Thoth ney QNX was very slick. I agree with Larry. It was very impressive at the time. So between Thoth (which was Unix-similar) and Minix (which was V7 Unix API clone) I think it is safe to say there are reasonable existance proofs for saying V7 was quite possible on the 8086/8088 family. Sent from my iPad > On Jul 4, 2016, at 2:13 PM, Larry McVoy wrote: > > QNX, which wasn't Unix compat at the time but sorta close, in the mid > 1980's was very very small and ran just fine on a 80286. If my memory > serves me correctly I had 4-10 people logged into that box on terminals. > > QNX, at least until they put real posix conformance in it, was a really > tiny micro kernel with the rest of the os in processes. It fit in a > 4K instruction cache with room to spare. > > QNX, in my opinion, is the only really interesting and commercially > proven microkernel. > >> On Mon, Jul 04, 2016 at 12:54:15PM -0400, Norman Wilson wrote: >> Greg Lehey: >> >> And why? Yes, the 8088 was a reasonably fast processor, so fast that >> they could slow it down a little so that they could use the same >> crystal to create the clock both for the CPU and the USART. But the >> base system had only 16 kB memory, only a little more than half the >> size of the 6th Edition kernel. Even without the issue of disks >> (which could potentially have been worked around) it really wasn't big >> enough for a multiprogramming OS. >> >> ===== >> >> Those who remember the earliest UNIX (even if few of us have >> used it) might disagree with that. Neither the PDP-7 nor the >> PDP-11/20 on which UNIX was born had memory management: a >> context switch was a swap. That would have been pretty slow >> on floppies, so perhaps it wouldn't have been saleable, but >> it was certainly possible. >> >> In fact Heinz Lycklama revived the idea in the V6 era to >> create LSX, a UNIX for the early LSI-11 which had no >> memory management and a single ca. 300kiB floppy drive. >> It had more memory than the 8088 system, though: 20kiW, >> i.e. 40kiB. Even so, Lycklama did quite a bit of work to >> squeeze the kernel down, reduce the number of processes >> and context switches, and so on. >> >> Here's a link to one of his papers on the system: >> >> https://www.computer.org/csdl/proceedings/afips/1977/5085/00/50850237.pdf >> >> I suspect it would have been possible to make a XENIX >> that would have worked on that hardware. Whether it >> would have worked well enough to sell is another question. >> >> Norman Wilson >> Toronto ON > > -- > --- > Larry McVoy lm at mcvoy.com http://www.mcvoy.com/lm