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40 Years of Multics, 1969-2009
gribll writes "October 2009 marked an important milestone in the history of computing. It was exactly 40 years since the first Multics computer system was used at MIT. The interview is with Multics co-developer, MIT Professor and Turing Award winner Fernando J. Corbato. Multics (Multiplexed Information and Computing Service) is regarded as the foundation of modern time-sharing systems. Multics was the catalyst for the development of Unix and has been used as a model of operating system design since its release four decades ago. There is also a picture gallery of Multics history."
"In hindsight we might have picked a simpler language than PL/I, . . ." Now there's an understatement!
I had to use it at a large energy company in Europe in the 1980s. It was actually a fantastic system.
Unlike VMS and IBM's mainframe OSes, it was actually pretty friendly to use. This attribute has clearly rubbed off on UNIX. While we'd spend months teaching some users how to use VMS, they'd get Multics within a few days.
The programming environment was also fantastic. It didn't support as many languages as VMS, nor did it have language interoperability that was as good, but it still supported more languages than you'd fine on typical UNIX systems of that era.
That said, it still was a beast compared to UNIX. UNIX was sly and sleek, and thus supported lower-end hardware better than Multics could. And UNIX was more portable, which eventually made it more widely available.
Still, I look upon my Multics days with a fondness I didn't find again until the early 2000s, when I was able to get a position administering a network of FreeBSD servers.
Multics was very influential, it provided Ken Thompson an example of what not to do. In other words, stick closely to the KISS (Keep It Simple) principle.
Bloat isn't really the right word. Multics had a lot more features than UNIX, and some really nice ideas (like the fact that files and memory used the same interface), but it required very high-end hardware for the time. It was a mainframe OS. It would not run on a minicomputer and so UNIX was written to port a game from Multics to the spare minicomputer that Thompson and Richie had access to. It turned out that UNIX, while inferior, was good enough for a lot of things, but saying Multics is bloated compared to UNIX is like saying Linux is bloated compared to MS DOS 3.
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and they waited until november to tell you!
I have a feeling that this "feature" got removed very soon after it snarfed the Computer Unit Director's screen.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
Can you really rate it as 40 years, since the last operational site was shut down in 2000? Shouldn't the timer stop when it dies, like with people? Do you give Columbus's age as over 500 years?
Who would win this election: Andrew Weiner vs Andrew Weiner's weiner.
indeed,
This episode of Multics was brought to you by the letters P and L and the number 1
I still miss the clean user interface (all command-line arguments meant the same thing, no matter which command was being executed) and fine documentation. But the GE645 / Honeywell 6800 architecture was never well-enough documented to make emulation feasible. And the descendants of Multics have implemented most of the features more-or-less. The world has moved on.
I've moved on, too. In 1978 I taught myself C; I've since learned and continue to program in C++, Java and Python, having discarded along the way Lisp, Pascal and Delphi.
And I use Windows mostly now. But my memory tells me that Multics was often faster for routine things like searching the file system. (Though the filesystem back then was only a few hundred MB.) And the processor back then was good for about 1 MIPS. Forget about color graphics. Animation? That was for cartoonists.
Anyway, this old-timer got a chuckle out of the article; thanks for posting the heads-up.
There are a few defunct projects on sourceforge and, I think, one live effort. I'm writing an emulator, but I haven't released any code yet.
CPUs are trivial. Systems can be hard.
Writing an emulator probably wasn't feasible before the sources were released two years ago. A few people started prior to that, but I can't imagine how.
Multics ran on somewhat complex hardware. In addition to the CPU, there were several other complex components including the system controllers, I/O multiplexors, and front end processors. Some of these were programmable or semi-programmable devices and much of the documentation is missing.
Now that we have compiler listings, assembly listings, a few documents, and a boot tape, the task seems feasible. Digging through the machine code on the boot tape and in the assembly listings partially makes up for the lack of decent documentation on some of the components.
My emulator is far from complete -- and it's almost 18K lines of code. It does read the boot tape and run about 2 million instructions, but crashes before finishing the boot process. The emulator doesn't yet know about disks or support instruction restart etc. There's a lot of work left to do.
I plan on cleaning up a few things and releasing it real soon now.