Retro Computing Enthusiast Tries Restoring a 1986 DEC PDP-11 Minicomputer (youtube.com) 52
More than half a century ago, Digital Equipment Corporation released the first of their 16-bit PDP-11 minicomputers, continuing the PDP-11 line until 1997.
This week long-time Slashdot reader Shayde writes: I've been working on a 1986 PDP/11 that I basically got as a "barn find" from an estate sale a year ago. The project has absolutely had it's ups and downs, as the knowledgebase for these machines is aging quickly. I'm hoping to restore my own expertise with this build, but it's been challenging finding parts, technical details, and just plain information.
I leaned pretty heavily on the folks at the Vintage Computing Federation, as well as connections I've made in the industry — and made some great progress... Check it out if you're keen on retrocomputing and old minicomputers and DEC gear.
The entire saga is chronicled in three videos titled "Barn Find PDP 11/73 — Will it boot" — part 1, part 2, and this week's latest video. "What started as a curiosity has turned into an almost 10-month-long project," it concludes, creeping up hopefully on the possibility of an awe-struck glimpse at the PDP-11's boot sequence (over two minutes long)
"So cool," responded Jeremiah Cornelius (Slashdot reader #137) in a comment on the submitted Slashdot story. "I have huge affection for these beasts. I cut my teeth in High School on a DEC PDP11/70 and AT&T SysV, and a little RSTS/E in 1979-82. We switched systems by loading different cakelid platters into the washing-machine drives, and toggling the magenta keys.
"I've thought about the Blinkenlights 7/10 scale emulator, tha uses an RPi, but I envy you and hope you have fun."
This week long-time Slashdot reader Shayde writes: I've been working on a 1986 PDP/11 that I basically got as a "barn find" from an estate sale a year ago. The project has absolutely had it's ups and downs, as the knowledgebase for these machines is aging quickly. I'm hoping to restore my own expertise with this build, but it's been challenging finding parts, technical details, and just plain information.
I leaned pretty heavily on the folks at the Vintage Computing Federation, as well as connections I've made in the industry — and made some great progress... Check it out if you're keen on retrocomputing and old minicomputers and DEC gear.
The entire saga is chronicled in three videos titled "Barn Find PDP 11/73 — Will it boot" — part 1, part 2, and this week's latest video. "What started as a curiosity has turned into an almost 10-month-long project," it concludes, creeping up hopefully on the possibility of an awe-struck glimpse at the PDP-11's boot sequence (over two minutes long)
"So cool," responded Jeremiah Cornelius (Slashdot reader #137) in a comment on the submitted Slashdot story. "I have huge affection for these beasts. I cut my teeth in High School on a DEC PDP11/70 and AT&T SysV, and a little RSTS/E in 1979-82. We switched systems by loading different cakelid platters into the washing-machine drives, and toggling the magenta keys.
"I've thought about the Blinkenlights 7/10 scale emulator, tha uses an RPi, but I envy you and hope you have fun."
DEC Logo used properly first time in 20 years. (Score:5, Funny)
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It's a logo that's been invalidated since Nov 11, 2001 [uspto.gov].
Though, someone in 2011 held it until 2022 when it was abandoned [uspto.gov].
Someone also tried to register it in 2020 [uspto.gov] but was opposed by the then current owner.
So far it looks to be completely abandoned again.
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Came to see it pointed out.
However, I fear that the logo was picked by accident, as it's obvious the current editors know not what the logo actually is for.
Good to hear (Score:5, Interesting)
Re:Good to hear (Score:5, Interesting)
I don't recall ever having worked with another machine that used octal as it's number format
Oh man (Score:5, Interesting)
Fun times. I remember my first real exposure to computing, back in high school advanced placement - a PDP 11/70 at the University of Puget Sound. Happily they had *just* upgraded from punch cards to DECwriters (IIRC - were there other terminals available?) My friends and I had a BASIC class there once a week, but free access to the computing labs... so we'd drive over there most evenings. Some of it was us trying to learn, but I must admit some of it was wasting paper playing Trek.
My college had an 11/40, also with the DECwriters... each with a paper tape reader/writer, to boot! I still have a few programs saved on spools of paper tape, somewhere...
I much prefer working in today's computing environment, but still - there was something magical about it back then that doesn't seem to exist anymore, at least for me.
Re:Oh man (Score:5, Interesting)
I know exactly how you feel. My first computer exposure was 1968, summer after 9th grade, participated in an NSF funded computer program at Univ of Pennsylvania. Some of the classes were in the room where the ENIAC was built. We used IBM 360/65's and RCA Spectra 70's as mainframes, but got to play on a PDP-8 running an oscilloscope trying to make it function as a graphical display. Back in high school, we got a PDP-S, with an added high speed tape reader. To boot the machine, you turned it, then from the front panel toggled in address and data for a (as I recall) 7-instruction program that read a slow speed tape reader from the teletype machine. That permitted feeding in a paper tape coil with a short program (I am only guessing now, but maybe 50-100 codes) which enabled interface to the high speed tape reader which read a long folded tape which filled up much of the 8K memory. That was the OS and Fortran. After that, we could play. In the late 70's, I was at a university hospital clinical studies center where the patients in that unit were plugged into a PDP-11, which was an advanced achievement for that time. It had the same general boot sequence, but we got to interface the machine to a lot of home grown hardware.
I feel that same way that there was something exhilarating about it all. We all looked forward to coming decades when machines would be more capable, but no one thought that personal computing would advance as much as it has. What we now take for granted, in ease of use and productivity, was replaced back then by a sense of pioneering excitement. Your last sentence "I much prefer ... something magical ...", you said it perfectly.
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"...there was something magical about it back then that doesn't seem to exist anymore, at least for me."
I suspect today's budding little hackers may be finding the same magic with ChatGPT and its ilk.
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We did programming for our 7th Form Applied Maths class at the Christchurch Polytechnic. It was across the road from my school and we used two PDP 11 computers running RT-11. We learnt to program numerical methods using BASIC. The computers were prone to overheating and "crashing" in summer, so I had to "bootstrap" them a few times using their front panel switches and some instructions taped above them. I spent many hours using them on my private projects, oblivious to the fact that the school was being cha
Dear EditorDavid (Score:2)
Minicomputer and microcomputer at once?
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Re: Dear EditorDavid (Score:2)
Is this a sign of the beginning of the end times ?
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But, from your submissions page :
I think, if you'd actually tried submitting a few stories, you'd know that the editors at Slashdot do generally edit the submissions.
FYI, about 1 in 4 of submissions get accepted. So dipping your toe in the water just the once isn't likely to teach you anything about the submissions process.
Now, I have frequently disagreed with the editing of my submission
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Erm, FUCK OFF.
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I'll treat your "FUCK OFF" argument with the contempt it deserves.
I wish I lived closer (Score:2)
Cool hobby (Score:4, Interesting)
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Do you know, I think I might go and reread Soul of a New Machine!
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An MV/8000 is a significantly more complex (and more powerful) machine than a PDP/11. I imagine that would be a lot more work.
Vax assembly = Hell (Score:5, Interesting)
We had pdp11 and microvax (fuck you autocorrect, I won) which were kind cool except for having to do projects in Vax assembly which was fucking nutso. The guys who came up with that just have been the first crack heads or were heavy lsd users.
384 unique instructions, multiple modes, instructions created specifically for certain languages (cobol), and other craziness. It's no wonder the next big thing was RISC.
Xtension (Score:4, Informative)
VAX set was designed as a 32-bit extension to the PDP-11, so you had x86 style instruction and mode creep.
The next big thing wasn't RISC, it was 68000 assembler designed for 32-bit from the ground up
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In my world it was RISC. YMMV. We never even looked at 68k because it wasn't interesting academically.
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Yeah, the first RISC machine I'd ever seen was a SPARC server, but that was probably in 1988. By that time, 68K machines had been around for nearly a decade. In fact, the SPARC server replaced a 68K-based 3/280. (The professor who owned it was doing Navier-Stokes computation for the Navy and always had to have the latest and greatest.)
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Yup,because I usually don't bother manually correcting on slashdot unless the wrong word dramatically changes the meaning or looks like line noise.
You knew what I intended, message delivered, success. Not worth my time to review and correct.
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Not worth my time to review and correct.
Then not worth our time to read. If you play fast and lose with facts the same way you do with grammar, then your message is justifiably disregarded.
If you think your time is more important than ours as we try to parse through your murdering of the language then your ego is also getting in the way of effective communication.
Thanks for so eloquently explaining where your priorities are.
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But you read it, quoted it, commented on it, understood it, spent time responding to it.
Have a nice weekend, AC troll.
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You're all anonymous trolls so who knows which of you is posting which trolls?
No one and it doesn't matter. You're all the same person as far as anyone knows or cares. If you have to post AC then you live with the consequences of being the same person. Tough shit, troll. You posted all of those things.
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Yup, we did the 11/780 too, thanks for reminding me and bringing back the nightmares. I gotta call a psychiatrist and a team of therapists now.
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I suspect your instructors were better than mine. All I remember is cold sweats. :-)
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Wasn't there a VAX instruction to evaluate a polynomial?
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Compared with other instruction sets of its day, the VAX instruction set was pretty consistent and most of the various addressing modes (which were based on those of the PDP/11) were available as operands with most of the instructions. Some of its specific instructions (like the queue instructions that manipulated doubly-linked lists) were integral to the design of the operating system. It was quite common for computers of the day to have instructions for dealing with packed decimal arithmetic - that's how
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Your handle is awesome, btw.
I appreciate the history lesson. You just taught me more about Vax than my instructors did in school.
Re:Vax assembly = Heaven (Score:2)
What I never liked
Re:Why? (Score:5, Interesting)
So you can watch a 300 baud DECWriter waste yards of paper while playing Star Trek?
Hey, we used to do that with our high school's PDP-8. One move per 11x14 sheet.
However, some company always donated countless reams of used tabular printouts to our school (I guess this was before anyone worried about data security), and we'd just load the fanfolds into the printer backwards and use the blank side.
Reduce, reuse, recycle.
Seems Like (Score:5, Funny)
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the poor guy is lost in a twisty little maze of passages.
"...all alike"
A bunch of Dec Hardware (Score:4, Interesting)
Seeing this old hardware being restored and running is really interesting. It's a tangible example of how much computing has changed.
Female to female floppy drive power cable (Score:2)
Am I missing something, or could one simply cut and splice the cables to do that?
https://youtu.be/dh52fhCBt0A?t=243
Hand toggled boot loaders (Score:2)
Unibus fan, but .. (Score:2)
Nice to see an 11/73 getting some love, but there are no doubt thousands of those out there in industrial use today.