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Putting a PDP-11 back to work

V

vord

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Joined
May 15, 2007
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4
Location
Bedford UK
Hi everyone. I seem to have fallen head first into the world of vintage computers by buying a 1984 Genrad 2515 (computer aided test system). It's running the RT-11 operating system with SDRC structural testing software (modal-plus and real time analysis).

I've actually picked it up to use it. It was by far the most capable machine for doing this sort of thing in it's day, and while technology has moved on the only real advantages of modern machines is the resolution available (and maybe a few extra features). Disadvantage of modern software is the software licencing cost for the sort of work this machine can do (analysing noise and vibration) can cost upwards of £10,000. Hence the Genrad.

It works perfectly at the moment (apart from never booting up first time). But I'm keen to get an image of the hard drive as that's not going to last forever and the machine would be useless without it. Still reading through the PDP-11 stuff here and on the internet, and am guessing clever things involving serial ports and emulators will be the way forward. Any pointers much appreciated.

Popped in to say hi and share some photos - here she is:
 

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Hello,

nice to know that someone out there is still using RT-11. I kept a LSI-11/73 CPU and 256KB main memory in my bookshelf, but I no longer have any peripherals to be able to boot it.

Concerning power consumption it is most probably better to use the SIMH emulator on a todays PC.

My other Q-bus system, a microVAX3 under VMS still runs great.

I still have a copy of the Modula-2 software which I developed for RT-11 in the 80's on the VAX: The M2 compiler/linker can use the full 22 bit address space of the LSI-11/23 and 11/73 under RT11SJ (and SHAREplus) for program code, abolishing the need to use overlays.
 
Very cool machine! I'm glad it'll still serve a purpose!

Welcome to the forums!
 
Vlad said:
FYI this is a year old thread >__>
XD
Click to expand...

Yeah and it took you all long enough to reply :-D

The poor old Genrad isn't very well at the moment. I was attempting a modal test (really cool thing that animates vibration shapes so you can see where the weak bits are in a structure). Takes a long time to do the test, and it was all too much for the Genrad - started making a lot of noise so I turned it off. I think the bearings in the hard drive are failing.

Bit stuck now. I understand the emulators won't interface with the front end built into the machine (includes analog to digital convertor but there will be other trigger and signal conditioning things in there). PC World doesn't have the hard drive :mrgreen: and in any case I have no way of getting the data off.

Still, the machine isn't dead yet, just needs a bit of work. And in the meantime it's interesting to visitors to the house who all think I'm crazy.
 
I always kinda wanted a desk side style Cray or maybe a Vax as a conversation piece, but I don't have the money or the room. Sad to hear the bearings are going out. I believe there was a thread here a while back about re greasing, would something like that work?

Better late than never :p
 
Vlad said:
I always kinda wanted a desk side style Cray or maybe a Vax as a conversation piece
Click to expand...

better run the simh.org vax emulator on your PC.
http://simh.trailing-edge.com/
even a microvax not only consumes floor space; it also needs more power than a PC with e.g., AMD64 X2 4850e (45W THP), while the chance is high, that the latter will run much faster than a microvax3.
 
An emulator though doesn't attract visitors' looks as much as the real thing.

I think we're striving from the topic, but at the computer club (c:a 1998-99) we once received a pile of VAXstations 3100/m76 and three VAXservers, one 3100 and two 4000. Only 1-2 out of ~30 members were really excited about the Vaxen. We installed the two 4000's as a cluster in our server room and some used them as file servers. For some reason they didn't like switched networks, so we had to interconnect them through an old 10 Mbps hub. The people at the IT department were curious why we all of a sudden had so much network traffic, and it turned out these VAX servers chit-chatted to eachother all the time.

The 3100 was brought home by one of the guys to double as his private server and base for a coffee table. :) A while later we cleared out all the VAX and I think the same guy got to bring all three servers home.

I wonder what we would've done if someone had donated a PDP. Depending on the model, I doubt we would've found space for one, much less had the experience in how to operate one.
 
> An emulator though doesn't attract visitors' looks as much as the real thing.

maybe I live in a different world ;) since none of my visitors ever wanted to see one of my dec vax or alphas although the weight of the former with a rack mount case is quite impressive. :)

the advantage of an emulator is that it weights nothing, and if you travel with a notebook (I don't), the the beloved pdp, vax and alpha are always with you. ;)
 
Perhaps you should line up your servers in your hall or the living room, so visitors can't avoid seeing them? ;-) Vlad seems to have high hopes that a such beast would become a conversation piece, at least the first time one sees it. At the moment, my own living room is cluttered full of Commodore PETs all over the floor, which certainly would raise a comment if I dared to bring home visitors. It even makes me boggle, in particular at night if I forget and stumble onto one of them on my way to the bathroom.
 
> if I dared to bring home visitors.

visitors are aware that there are varying risks when visiting any individual's home. your floor is cluttered with commodores and my garden is a paradise for viper snakes*. it's true! nevertheless, in case I mention it to potential visitors, it works to keep most visitors out. except the postman who still doesn't know that one of them is nesting beneath the letter box. ;)

*) Vipera aspis to be specific, an ovoviviparous species, very discret in all aspects as long as you don't step on them. ;) a Vax, although it sounds like venom, is harmless in contrast to a new born vipera.
Unix sounds like a bug - we won't talk about "C" today. ;)
 
Do you call very thick computer cables "snakes" in English too? I'd think when you deal with those mini's and servers; long, thick cables ringling on the floor are common.
 
That's a shame, I hope he's been PM'd/emailed too I'd go & knock on his door if I knew where it was, he's only a few miles up the road from me!
 
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