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Coherent Use

I have a 386-25 with 4-MB of RAM on it. I planned to use that 386 as the platform for UNIX like environment. Since Coherent is unstable would BSD work on a 386 as described?
 
A vintage FreeBSD (2.x series) or NetBSD (1.5 series) should work. It would be much better as well, being designed for the 386 vs the 286 that Coherent is designed for. Coherent is closer to Xenix.

4MB might be a bit tight tho.
 
Thanks for bringing this topic up; I hadn't been aware of this software before. Interesting that the sources are available as well. If you are working with a 286 machine anyway - I would second the opinion that It might be nice to set up just for historical interest. You would probably be the only kid on your block with one.
 
Pepinno said:
If I remember correctly Coherent binaries could only handle 64 KB.
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Yea I'm pretty sure Coherent processes are the "tiny" memory model, meaning combined 64K code/data per process.

That's not horrible, particularly for the time but it's not "real" virtual memory. I think it can swap processes, but that's about as far as it can go. Swap processes, not pages.

Funny thing, thinking about this, not that I've looked, but trying to get this running today might be a trick. I don't know of any 286 VMs out there. I guess it would potentially run on a something like QEMU, but those are mostly 486+ simulators. Not sure how well 286 system code ports to a 386, 486, or higher.
 
Pepinno said:
Looks like (Coherent's Book) it's available here: http://www.bitsavers.org/pdf/markWilliams/Coherent_Revision_8_1992.pdf
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I've given a fast look at the book, and it has some interesting things:
- The copyright is 1982-1992, and there are two Coherent editions: Coherent-286 and Coherent-386.
- The book's credits page contains the MWC (Marc Williams Company) address, phone number, fax number, and Internet-style email address (sales@mwc.com).
- The book's description of the "mail" command says the Coherent system can only dispatch email to local users, or to remote users via UUCP through serial/modem lines. So the Coherent system had no Internet support on 1992, however the authors of Coherent deemed their own Internet-style email address as important enough to publish it on the first pages of the book.

Coherent was already obsolete by 1992.
 
This Coherent?
IMG_20240622_144034999.jpg

There are several pages out there about Coherent and the wisdom of MWC working on X11 instead of TCP/IP. There is a port of the KA9Q IP suite out there, though. And as has been mentioned Coherent is now BSD-licensed Open Source if anyone wants to take up that mantle.....

MWC folded in 1995; by that time Linux was beginning to take off.

EDIT: Udo Munk had a page up about running Coherent on Virtualbox; Wayback Machine archive link: https://web.archive.org/web/20170210102146/http://www.autometer.de/unix4fun/coherent/index.html

There's also https://itsfoss.com/coherent-operating-system/ and the github project https://github.com/gspu/Coherent
 
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lowen said:
There are several pages out there about Coherent and the wisdom of MWC working on X11 instead of TCP/IP.
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Kind of being neck deep in the world of multi user business computing, I honestly didn't encounter actual TCP/IP networking until the mid- to late 90s.

All of our clients used terminal concentrators to host serial terminals and printers running business software.

Our real first forays into actual networking were PCs running using terminal software to connect to the machines.

The mini market for multi user applications was quite large, without any need to actual network to other systems. MWC was, perhaps, late, but they could easily have sold into a VAR market looking for low cost, multi-user systems. Competing with the likes of SCO. We never encountered it in the field ourselves, and we sold to most every computer on the market then.
lowen said:
Udo Munk had a page up about running Coherent on Virtualbox;
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Any idea what happened to his site? It up and vanished. Disappointed to see that, but I have not heard anything (hardly means anything, not that I'm in any kind of loop). But he had a very nice CP/M site.
 
whartung said:
Yea I'm pretty sure Coherent processes are the "tiny" memory model, meaning combined 64K code/data per process.
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I think they actually have separate code/data pages for 128k, IE, “small” model?

FWIW, this is effectively the same as UNIXes for PDP-11. The address extension/mmu system for bigger PDPs no doubt “inspired” Intel when they taped out the 286.
 
Eudimorphodon said:
I think they actually have separate code/data pages for 128k, IE, “small” model?
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Yea, I wasn't sure. The small model is more complicated. That is, if I get a pointer to a function and dereference it, do I get data from the code segment, or indeterminate data from the data segment that just so happens to be at the same offset.

Hardly a show stopper, having all 64K for data would be a boon.
 
Eudimorphodon said:
If I had a suitable 286 or better I’d probably want to try it once, but my strong impression is there’s not much you can actually do with it.
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I always wanted to try on my 286, but I only found 386+ versions. So I never tried except for a single VM experience. Would have been interesting, but I like TCP/IP connectivity...

whartung said:
That is, if I get a pointer to a function and dereference it, do I get data from the code segment, or indeterminate data from the data segment that just so happens to be at the same offset.
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Does it matter? In C, you are only allowed to convert a pointer to an integer and back to a pointer of the same type - everything else is implementation-defined. Or in other words, if you call a function through that pointer, it's probably your code segment - if you memcpy from it, it's probably your data segment.
 
Svenska said:
I always wanted to try on my 286, but I only found 386+ versions. So I never tried except for a single VM experience. Would have been interesting, but I like TCP/IP connectivity...
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I had an emulated PDP-11 with the maximum 4MB of RAM running BSD 2.9 on the company network for a month just for laughs, I kind of feel like that scratched my 16 bit UNIX itch. (TCP/IP worked fine, you could telnet into the box and run various trivial things. The docs said you could in theory even set it up as a router, although it said that the the route code was mostly untested on PDP-11 by that point and performance was expected to be terrible.)

Minix 2.0 will run on a 286 and has tcp/ip support, so it’s probably a better bet than Coherent (on 286 it has the same Small model memory restriction), but I can’t say I’ve actually done anything with Minix beyond booting it a few times.
 
alejack12001 said:
Has anyone ever tried to use Mark William's Coherent on a vintage machine?
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Well, at the time I was using it the machine was not at all "vintage," but yes, it was my primary machine for a couple of years before I upgraded to Xenix 286.

alejack12001 said:
I have a 386-25 with 4-MB of RAM on it. I planned to use that 386 as the platform for UNIX like environment. Since Coherent is unstable would BSD work on a 386 as described?
Click to expand...
For a '386 you'd be much better off running NetBSD (or FreeBSD), as others here have mentioned. I don't know how recent a version you'd need, but the older versions will definitely work fine with 4 MB of RAM. (In fact, that was what my main desktop system, running NetBSD, had in the mid-'90s. I had a 486, though.)

Perico said:
If I remember correctly Coherent binaries could only handle 64 KB.
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I seem to recall that it supported larger memory models (though of course with multiple 64K segments); I definitely had Taylor UUCP running on it, and also Perl I believe. The former might have worked with just split I/D ("small" model), but ISTR that Perl was fairly huge.

Perico said:
- The book's credits page contains the MWC (Marc Williams Company) address, phone number, fax number, and Internet-style email address (sales@mwc.com).
- The book's description of the "mail" command says the Coherent system can only dispatch email to local users, or to remote users via UUCP through serial/modem lines. So the Coherent system had no Internet support on 1992, however the authors of Coherent deemed their own Internet-style email address as important enough to publish it on the first pages of the book.
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You don't need Internet support for Internet-style e-mail addresses to work; you just need someone else with Internet connectivity to accept and relay the messages to you, which is exactly what I did for my "Internet-style" e-mail addresses. (I also had netnews relayed to me.)
 
I haven't personally used Mark William's Coherent on a vintage machine, but I've heard mixed experiences. Some folks say it works like a charm with a bit of tweaking.
 
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