48-Year-Old Multics Operating System Resurrected (multicians.org)

"The seminal operating system Multics has been reborn," writes Slashdot reader doon386: The last native Multics system was shut down in 2000. After more than a dozen years in hibernation a simulator for the Honeywell DPS-8/M CPU was finally realized and, consequently, Multics found new life... Along with the simulator an accompanying new release of Multics -- MR12.6 -- has been created and made available. MR12.6 contains many bug and Y2K fixes and allows Multics to run in a post-Y2K, internet-enabled world.
Besides supporting dates in the 21st century, it offers mail and send_message functionality, and can even simulate tape and disk I/O. (And yes, someone has already installed Multics on a Raspberry Pi.) Version 1.0 of the simulator was released Saturday, and Multicians.org is offering a complete QuickStart installation package with software, compilers, install scripts, and several initial projects (including SysDaemon, SysAdmin, and Daemon). Plus there's also useful Wiki documents about how to get started, noting that Multics emulation runs on Linux, macOS, Windows, and Raspian systems.

The original submission points out that "This revival of Multics allows hobbyists, researchers and students the chance to experience first hand the system that inspired UNIX."

Comments

no systemd ;)

[TheGratefulNet]

maybe its worth looking into..

Wonder if my account still works?

[sk999]

I had a Multics account way back - used it solve problem sets in Physical Chemistry. It would be cool to resurrect my account, but I don't remember the password. Is there a password reset function?

Re:Wonder if my account still works?

[OolimPhon]

Is there a password reset function?

Yes, but your email address has to have UUCP bangs in it :)

Re:What can we do with it?

[Gay Boner Sex]

History. Read. Learn from the past. General concepts and themes do not change.

Multics didn't have many "problems," or at least many more than other systems of the time. (the IBM TSS/360, in 1967, turned out to be too slow for supporting more than one user concurrently, and of course OS/360 was plagued with bugs and performance problems). There is a common myth that Multics "failed," but in fact the system was first described in 1965, released in the early 1970s, and lasted until 2000 (Salus himself said, "With Multics they tried to have a much more versatile and flexible operating system, and it failed miserably."). However, the lifespan, in particular the thirteen years after development ceased in which installations continued to use it, doesn't suggest failure. It's certainly true that AT&T management decided that the project wasn't relevant to them, and that's sufficient for Unix history.

Bam!

Still

[ArchieBunker]

a more capable operating system than HURD.

Re:What can we do with it?

[Gay Boner Sex]

Where did I read?

Market research at Digital by walking up to someone ELSE'S mainframe and waiting for it to do another "load in the washing machine" before it would even think about giving you the time of day and sniff your card stack.

Re:What can we do with it?

[udin]

The 360 wasn't particularly slow--the time-sharing operating system TSS/360 was initially a mess (so was OS/360--at first--see Brooks,"The Mythical Man Month") and I don't recall that they improved the TSS to where it was usable. There was a project in (as I recall) the IBM lab in Cambridge MA that did an interesting and credible virtual machine OS for the 360 (I vaguely recall it was for a middling level 360) that was developed because the "official" time-sharing system TSS/360 was such a mess.

I used it at MIT in the early 80s.

[www.sorehands.com]

I was a project administrator on Multics for my students at MIT. It was a little too powerful for students, but I was able to lock it down. Once I had access to the source code for the basic subsystem (in PL/1) I was able to make it much easier to use. But it was still command line based.

A command line, emails, and troff. Who needed anything else?

Re:I used it at MIT in the early 80s.

[DaiyuHurst]

Who needed anything else?

What about Lynx?

(On that note, sometimes I find myself tempted to disable images and videos on Chrome...)

Lynx, the text-mode web browser? No. No real network access yet. The front-end processor emulation turns TELNET connections into what Multics thinks are serial ports. We don't have a TCP/IP network stack. The NSA didn't pass that along to the archivists. We have most of an older ARPAnet (NCP) stack, and I think, a full X.25 stack. Email currently works only between users of a given system. But we are planning to resurrect bang-path so we can exchange email with the outside world. This is mostly all outside the emulator though, it's part of our ongoing development of Multics itself. I think once we do that, we'll also have a rudimentary web server in the form of Bjorn Victor's 'httpd' written in MACLISP for ITS. *Then* we could port Lynx. We do have a working C compiler!

It's not the end!

[Gravis Zero]

Considering that processor was likely made with the three micrometer lithographic process, it's quite possible to make the processor in a homemade lab using maskless lithography. Hell, you could even make it NMOS if you wanted. So yeah, emulation isn't the end, it's just another waypoint in bringing old technology back to life.

Re:What can we do with it?

[PolygamousRanchKid]

Where did you read that the 360 was so slow it could only handle one user?

This rumor originated in Dr. Gene Amdahl's lesser known history of the IBM mainframe titled, "The Apocryphal Man Mouth," which examined the contradictory cognitive dissonance of software project managers who think that they are running a development process, when, in fact, they are simply running their own mouths. The book is filled with the taller tales of the seminal computer industry, like the instance of Professor Forman Acton of referring to the inventors of that new-fangled language, collectively as, "The FORTRAN Boys."

Apparently, a disgruntled IBM customer complained about about the one user design limitation of OS/360, and asked the IBM sales rep when an upgrade to more than one user would be available. The IBM sales rep pulled out a little plastic case containing resistors, uttered some bizarre incantation like, "Bad Booze Rots Our Young Girls But Vodka Goes Well", and enumerated the prices of the resistors, and how many users each one would support. One cold solder joint later, and the IBM customer was a happy camper.

There was also something in there about Oliver North nearly starting World War Three, because he was forced to use IBM's OrifaceVision/2, which was like their PROFS Professional Office System for mainframes, but it was much more secure, because it was based on OS/2, which meant it never ran or was used at all, and you can't get any more secure than something that just doesn't work . . .

. . . oh, and speaking about IBM SAA AD/Cycle, don't mention that, unless you say "Mary Hartman! Mary Hartman" three times to a mirror, and conclude it with that Islamic curling Eight-ender cry, "Allah Hu Almaraq!", ("God is Gravy!"),

. . . and . . .

Multics

[Tom]

The original submission points out that "This revival of Multics allows hobbyists, researchers and students the chance to experience first hand the system that inspired UNIX."

More importantly: To take some of the things that Multics did better and port them to Unix-like systems. Much of the secure system design, for example, was dumped from early Unix systems and was then later glued back on in pieces.

Re:Multics

[tlhIngan]

More importantly: To take some of the things that Multics did better and port them to Unix-like systems. Much of the secure system design, for example, was dumped from early Unix systems and was then later glued back on in pieces.

Basically Multics gave way to the rise in minicomputers who could not handle such a heavy OS, so the developers created Unix ("Multics without balls" - a play on Eunuchs). One thing they did was if there was every a problem, you called panic(). Aka, the kernel panic on Unix. Much simpler and much lighter than trying to recover (though modern Linux is pretty hard to panic() without failing hardware - it has enough built-in self checks that in general it'll handle misbehaving kernel drivers).

There's also historical interest - don't you want to see what the predecessor to Unix and C was? Unix was popular because it was a lightweight OS at the time that was multiuser and multiprocessing, a change from CP/M and DOS. It's why people run emulators of the Apollo Guidance Computer with the original software. It's neat, it's interesting.

Re:Multics

[squiggleslash]

Also worth pointing out - and I'm not expressing any views on Multics myself here - while it's technically correct that Unix was "inspired" by Multics, it was inspired as in "You're doing it all wrong! THIS is how you should write an operating system." Ken Thompson and Dennis Richie felt Multics was far too complex and reliant upon unusual hardware. Multics was also one of the more serious attempts to create proto-cloud computing - the concept was that people wouldn't own computers, they'd just pay AT&T for an account and a connection to a computer AT&T would own - plus, you know, per minute fees, per CPU cycle fees, per kilobyte fees, etc. How much this played into the design - beyond obvious issues like security - I can't comment upon, but I do know it meant the design wasn't dependent upon concepts like "Really should run on conventional computer designs."

As I understand it, there's very, very, very, little resemblance between the two beyond what you'd expect between two operating systems that shared some designers.

Re:Multics

[davecb]

The Honeywell salesforce of the day weren't quite sure how to sell a big timesharing system, and referred to Multics as "a machine big enough for everyone in Boston". They were very much into selling "one computer per company" instead, and flogged GCOS to all sorts of unsuspecting companies, including the University of Waterloo. The wouldn't have had a clue about how to sell one computer per person

Re:What can we do with it?

[OolimPhon]

As I recall, most Multics (Multicii? Multicesses?) ran at University shops all over the western world. They had a big requirement for multi-user access in a way that most businesses didn't - at the time.

What killed Multics was the Personal Computer - why be forced to use a terminal to access a mainframe somewhere else in the world, and over 300 baud if you were lucky, when you could have your own processing power right under your desk?

The original minicomputers, like PDP, VAX and Wang, were all small timesharing computers whose operating systems owed a lot to Multics (and subsequently Unix). PCs brought a whole change of emphasis.

Re:What can we do with it?

[Anne Thwacks]

Multics didn't have many "problems,"

I am not so sure about that. In 1973, I repeatedly brought down the system by running a Fortran program in which I declared an array names ARRAY. I cant remember whether this was illegal or not, ARRAY may have been a reserved word, but in the context of Fortran 4, that could have depended on where it was used.

I would not have complained if I got a printout with an error message - probably "SYNTAX ERROR AT OR NEAR LINE 1 COLUMN 1". Instead the entire OS would crash! This happened several times a day for several days before anyone realised it was me. It was then possible to figure out what I had done wrong only by deliberately crashing a few more times! I am sure that, over a 6 month period, I had few days without a system crash. I may not have been the cause of most of them.

In mitigation, none of my BASIC programs crashed bringing down the whole system. (But they were only concerned with gathering data from users. The Fortran stuff was solving Maxwell's wave equations).

Yes, I did ask for a PDP8 instead. I don't know how the costs would have compared. What I do know, is my employers made a colossal amount of money from that software, while I was paid £11 per week for 6 months. After it was written, an apprentice could do in 30 minutes what had previously taken a degree level physicist 3 months - and not only get the right answer, but prove that he had, before gold plated parts were manufactured to the resulting spec. Then, if there were manufacturing errors, predict whether the resulting predict would still be in spec over a wide range of parameters, requiring only a single 30 minute lab test to confirm my predictions, rather than 6 months field tests at the top of a 30 metre mast IN A FIELD WITH COWS or on the top of a war ship at sea - and other scenarios where failure was rather expensive.

OK, so computers cost $1M in those days - the payback could be many times that - per month. (But even then, engineers were treated like shit).

Re:Endian-ness

[DaiyuHurst]

Is it big endian, little endian, or bellend-ian?

Lol@bellendian. The GE635, GE645, Honeywell 6180, and Honeywell/Bull DPS8/m were all big endian machines. The emulator is endian-flexible.

Influence on Unix

[nuckfuts]

From here...

The design and features of Multics greatly influenced the Unix operating system, which was originally written by two Multics programmers, Ken Thompson and Dennis Ritchie. Superficial influence of Multics on Unix is evident in many areas, including the naming of some commands. But the internal design philosophy was quite different, focusing on keeping the system small and simple, and so correcting some deficiencies of Multics because of its high resource demands on the limited computer hardware of the time.

The name Unix (originally Unics) is itself a pun on Multics. The U in Unix is rumored to stand for uniplexed as opposed to the multiplexed of Multics, further underscoring the designers' rejections of Multics' complexity in favor of a more straightforward and workable approach for smaller computers. (Garfinkel and Abelson[18] cite an alternative origin: Peter Neumann at Bell Labs, watching a demonstration of the prototype, suggested the name/pun UNICS (pronounced "Eunuchs"), as a "castrated Multics", although Dennis Ritchie is claimed to have denied this.)

Ken Thompson, in a transcribed 2007 interview with Peter Seibel[20] refers to Multics as "...overdesigned and overbuilt and over everything. It was close to unusable. They (i.e., Massachusetts Institute of Technology) still claim it’s a monstrous success, but it just clearly wasn't." He admits, however, that "the things that I liked enough (about Multics) to actually take were the hierarchical file system and the shell—a separate process that you can replace with some other process."