In 1997 a set of DEC tapes were provided by Dennis Ritchie, as historical artifacts for those interested in the gestation of the UNIX operating system. The resulting archive files have recently been analysed by [Yfeng Gao], who has succeeded in recovering a working UNIX version from 1972. What makes it particularly interesting is that this is not a released version, instead it’s a work in progress sitting somewhere between versions 1 and 2. He’s therefore taken the liberty of naming it “V2 Beta”.
If you happen to have a PDP-11/20 you should be able to run this operating system for yourself, and for those of us without he’s provided information on which emulator will work. The interesting information for us comes in the README accompanying the tapes themselves, and in those accompanying the analysis. Aside from file fragments left over from previous users of the same tape, we learn about the state of UNIX time in 1972. This dates from the period when increments were in sixtieths of a second due to the ease of using the mains power frequency in a PDP, so with a 32-bit counter they were facing imminent roll-over. The 1970-01-01 epoch and one second increments would be adopted later in the year, but meanwhile this is an unusual curio.
If you manage to run this OS, and especially if you find anything further in the files, we’d love to hear. Meanwhile, this is not the oldest UNIX out there.
Featured image: “PDP-11/20 Rocker Switches” by Don DeBold
Linux has superseded Unix, and a pure RUST written OS may replace Linux! Just as long as the model/ethos is maintained then the world will keep spinning – affiliation/bias is not required!
recent developments might jeopardize the rust inclusion. And Darwin (Apples kernel) is also still very much Unix alike too. with other words, what are you actually trying to comment on the article? historically its cool and interesting what they have recovered.
Seems like one of the those armchair “computer scientists” stirred up in the socials during the Rust maintainer kerfuffle trying to draw a correlation between Linux replacing Unix to Rinux(?) replacing Linux, because (insert evil reasons here). Safe to ignore.
MacOS IS Unix. https://www.opengroup.org/openbrand/register/
Who’d have thought that Apple would be one of the few companies that are keeping Unix alive in the modern world?
(for the time being…)
Another small company also has a living version of Unix “in the modern world” IBM AIX.
There are also freebsd, openbsd and netbsd. Then there is illumos (the successor to opensolaris), hp-ux, and presumably yet more.
Real Unix is not dead.
Also, according to what I find on the internet (and taking upper limits for Linux), there are some 39 million computers in the world that are running Linux. While there are some 100 million computers running Macos.
But wait, Jim! That’s not all! Even though iOS cannot really be called a ‘Unix’ system, iOS IS using the same kernel as MacOS. So you could argue that iOS is also Unix.
And then we are talking about 2.2 BILLION computers running Unix.
And I didn’t count IBM computers running AIX, HP-UX, SCO UnixWare or SCO OpenServer.
So, now I am wondering: where did Linux supersede Unix? Maybe that Linux is free? Well, MacOS is free too, I didn’t have to spend one single dime for it. Ok, to be fair: I had to buy an expensive Macbook.
I think this post properly restores order to any confusion around Linux and Unix, no?
No. But nice try.
You seem to have missed the fact that Android uses the Linux kernel (albeit heavily modified), so if you’re going to count all iOS devices as Unix then you have to count the Android devices as Linux as well. Personally though, I don’t think it’s worth getting too worked up over.
That was meant to continue..
I don’t think it’s worth getting too worked up over. This article is about the recovery of an old and unreleased version of an OS whose design philosophy has shaped the majority of computing as we know it.
“Free with purchase” is not free, you still need to pay money.
The best part of this is that Linux is very like unix, but is not Unix™. Meanwhile MacOS is Unix™, but is very unlike unix.
Hmm. Such sayings once again confirm my suspicion that Linux is a cult. 😮💨
Linux is for people who like owning their stuff. Emacs is the real cult.
“If you happen to have a PDP-11/20 you should be able to run this operating system for yourself”
Yeah, I think have one lying around somewhere for emergencies… Let me check the basement. You never know when you need a DEC minicomputer!
If you are interested you can buy several PDP models from obsolescence.dev (currently 8, 10 and 11) which use a Raspberry pi for the actual compute power.
The PiDP-11 can also use an FPGA based PDP-11 to provide the processor power.
The PiDP-11 is a scale model of the original front panel while the PiDP-10 is a full size replica of the original front panel. None of them have the massive cabinets behind them as they are no longer needed for the processor and memory.
Except that the PiDP replicas use SIMH as the emulator, which this version of Unix will not run on.
The PiDP-10 is not a full-size replica. It’s about 60% size. The original mounted in a 31″ wide rack!
I keep mine right next to my interocitor.
Now that’s when SF was SF.
You don’t have a PDP11? Well why not?
Nice seeing the bootstrap switch’s on that PDP…worked with 11/40 and 11/70s at Presidential Insurance and Baker Oil Tools…mid 70s. Thanks for this article.
JB