This week the "Old Vintage Computing Research" blog published a 21,000-word exploration of the DEC PDP-11, the 16-bit minicomputer sold by Digital Equipment Corporation. Slashdot reader AndrewZX calls the blog post "an excellent deep dive" into the machine's history and capabilities "and the classic Venix UNIX that it ran." The blogger still owns a working 1984 DEC Professional 380, "a tank of a machine, a reasonably powerful workstation, and the most practical PDP-adjacent thing you can actually slap on a (large) desk."
But more importantly, "It runs PRO/VENIX, the only official DEC Unix option for the Pros."
In that specific market it was almost certainly the earliest such licensed Unix (in 1983) and primarily competed against XENIX, Microsoft's dominant "small Unix," which first emerged for XT-class systems as SCO XENIX in 1984. You'd wonder how rogue processes could be prevented from stomping on each other in such systems when neither the Intel 8086/8088 nor the IBM PC nor the PC/XT had a memory management unit, and the answer was not to try and just hope for the best. It was for this reason that IBM's own Unix variant PC/IX, developed by Interactive Systems Corporation under contract as their intended AT&T killer, was multitasking but single-user since in such an architecture there could be no meaningful security guarantees...
One of Venix's interesting little idiosyncrasies, seen in all three Pro versions, was the SUPER> prompt when you've logged on as root (there is also a MAINT> prompt when you're single-user...
Although Bill Gates had been their biggest nemesis early on, most of the little Unices that flourished in the 1980s and early 90s met their collective demise at the hands of another man: Linus Torvalds. The proliferation of free Unix alternatives like Linux on commodity PC hardware caused the bottom to fall out of the commercial Unix market.
The blogger even found a 1989 log for the computer's one and only guest login session — which seems to consist entirely of someone named tom trying to exit vi.
But the most touching part of the article comes when the author discovers a file named /thankyou that they're certain didn't come with the original Venix. It's an ASCII drawing of a smiling face, under the words "THANK YOU FOR RESCUING ME".
"It's among the last files created on the system before it came into my possession..."
It's all a fun look back to a time when advances in semiconductor density meant microcomputers could do nearly as much as the more expensive minicomputers (while taking up less space) — leaving corporations pondering the new world that was coming:
As far back as 1974, an internal skunkworks unit had presented management with two small systems prototypes described as a PDP-8 in a VT50 terminal and a portable PDP-11 chassis.
Engineers were intrigued but sales staff felt these smaller versions would cut into their traditional product lines, and [DEC president Ken] Olsen duly cancelled the project, famously observing no one would want a computer in their home.
Read more of this story at Slashdot.
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