[TUHS] History of cal(1)?

[Dan Cross via TUHS]

On Thu, Sep 18, 2025 at 3:52 PM Clem Cole <clemc at ccc.com> wrote:
> [snip]
> But I'll take a stab at the communications within the CS Research Community during the 70s, which I lived in.

Thanks, Clem: this is just the sort of thing I am interested in.

I realize this is veering off toward COFF territory, but another
couple of follow-up questions; inline.

> As we all know, Unix spread quickly outside of MH to researchers, and a great deal of development took place "on the outside."  Some of those ideas came back to the Research versions, but not all.   But I think there was a good bit of cross-pollination within the community — even before Usenet or the Internet itself.   Sometimes we would swap magnetic tapes directly, and often we would bring tapes to a conference with our work and come home with work from others.  We knew each other and talked.

So I sort of wonder if the Multics folks also showed up to some of
those conferences: SOSP, for example. I imagine people like Fano and
Corby attended. And the Unix community coalesced quickly and became
quite strong (as we all know), I wonder about interaction with other
communities.

To be a tad pithy about it, did folks get together for coffee during
the hallway track? Grab dinner or a drink in the evening? That kind of
thing.

> Taking MetCalfe's law into account, because there so many Unix installations (and we were all talking to each other), that style of sharing could not happen with Multics,  I will posit that by 1975 most, if not nearly all, researchers in the systems world were at least familiar with Elliott Organick's 1972 book — "The Multics System: An Examination of its Structure," and many of us had read it and trying to learn lessons from it.  It was a text that was referred to in my undergrad OS course, and by the time I was a grad student working in systems, it was pretty much assumed that everyone in the room had read it.
>
> I certainly thought Multics had some cool ideas. However, I barely touched a Multics system in those days via my limited remote access (MIT's system). And I never physically saw a Multics-capable processor until many years later. I admit that from reading Organski's book, I had some wild images of computer operators mounting mag tapes so a program could continue execution after a segment defined as not being directly addressable.  So while I was familiar with Multics,  I certainly "knew" a lot more about UNIX.  I had it, and I was hacking its kernel.   I personally did little of what we call programming on Multics, and at the same time, I was being paid to program in Unix (and some TOPS-10/TOPS-20 shop).
>
> I don't think I'm really unique here.   If the data from website Multicians.org is correct, there were just too few Multics installations to be found (11 in 1975), and only two were at universities (MIT and the University of Louisiana). The other nine were at commercial sites.  Note that in 1975, we know there were at least 5 times the number of Unix installations.  Most of these sites were ones that had had some level of CS Research.  By 1979, the numbers were 25 for Multics and over 600 for Unix.
>
> By 1979, Multics OS was stable, and the hardware to run it (the "3rd generation" H6180 had been on the market since 1973) had certainly matured from the original GE-645. So why did Multics not play a more significant role? Once again, core economics of the time played a huge part. If you use Google AI, it will tell you that a Honeywell H6180 computer system running Multics, like MIT was running in 1979, had a list price of about $7 million when it was introduced. This price included a complete system with multiple components, not just the central computer unit.  Now think about a PDP 11/34, with full 256K bytes of memory, a couple of RK05 and probably an RP04 equivalent as its disk, 9-track tape, Printonix printer, and 16 serial ports using after-market DH11 — a pretty standard V7 installation, which costs approximately $100-150K.  Even if you ran it on a Vax, it was not more than approximately 3 times that number.  But this is a massive difference from the $7M for a Multic system.
>
> It's a simple Christenson disruption —  the "lesser" system wins over the earlier, more "mature", and full-featured, "better" one.  As a result, cross-pollination opportunities were not available.   Unix/V7 and its derivatives got the attention of units because the economics favored it.  Just like Linux receives today.

These are really great points. It sure seems like Multics has had a
huge influence, but indirectly, as it was difficult to come by for
actual use.

Thanks again, Clem.

        - Dan C.