The other day my RD54 just stopped rotating, dead in its tracks, while it
was running. I guessed one of the motor control power transistors may have
failed. I assume they are the series of 6 chunky ones attached to a single
heatsink. I have desoldered them (en-masse) and tested them with a Peak
DCA55 tester, and they all appear to be working. Does anyone have any other
suggestions? Has anyone ever repaired an RD54 control board?
Regards
Rob
For those who don't know, Monash University (Melbourne Australia) has
had the chassis of a B7800 CPU sitting around under a stoir case, left
over from the days when a series of large Burroughs systems had been
in use there during the seventies.
I'm no expert on Burroughs systems, but from all the Internet based
trawling I've done over the years it appears that Burroughs had a
'scorched earth' policy, and systematically reclaimed and disposed of
all B5000 and onward family machines. At least to date, I haven't been
able to find any other surviving example of a B5000 family machine (or
major components). Naturally I'd be very happy to be proved wrong.
Unfortunately all cards and power supplies had been removed but it
still had the basic frame, backplane (very impressive in it's own
right) and two large front control panels all in place (also very
impressive).
(I've been told that the front panels were pulled prior to disposal).
Many of you will be familiar with Ralph Klimek and his amazing stories
of life as a technician with these machines.
He has some pictures of this particular frame, about mid way down this
page on his site:
http://users.monash.edu.au/~ralphk/burroughs.html
Because I live close by, I was dropping in every so often to check up
on both this frame, and a (smaller) VAX 11/780 sitting next to it.
Because the Uni has quite a decent vintage computer display in place
at it's Caulfied campus, I had felt comfortable that both machines
were safe.
On a relatively recent visit (a few months ago, late last year? I'm
not quite sure as life is a bit of a blur at present) I noticed that
both machines had gone, and that some renovations were taking place in
the building.
I felt that the machines must be safe but decided I should try and
make contact to be sure (working in ICT for so long, I should have
known not to trust an assumption),
A few days ago I got a note back saying that the Uni had requested the
builders to remove the B7800 chassis and dispose of it (the 11/780 was
moved to the Caufield collection).
Since then I've gone on a bit of a campaign to try and find out of the
machine might still be sitting somewhere with the builder (or their
sub-contracter). It's a very long shot, but in this case I think most
here on the list would agree it's worth it? Apparently the scrap metal
value would be quite low at the moment, and hopefully whoever has it
has been too busy to deal with disposal yet (a long shot, as I said).
I've managed to speak to numerous people both inside the Uni and the
builder, but have realised from them that my enquiries now need to be
pushed four ways - into two Schools within the Uni, and also two
service departments.?My problem is that I'm attempting to get a
startup software company off the ground, so time isn't something that
I've got any of, let trying to push my way through contacting people
within four different internal departments (and sitting through all
the on-hold music, call transfers & drop outs).
I don't think that the Uni wants this chassis at the end of the day.?
Is there anyone who can attack this at a higher level? I'm happy to
pass on relevant details to anyone who could help positively (I don't
want to cause unnecessary aggravation by posting everything here, the
people I've spoken to have already been as helpful as they can).
If it's true that it is possibly one of the last existing CPU frames
of the B5000 family, and if it went to one of the major Museums in the
US as a result, that would be a great outcome (if it still exists at
all).
Regards Evan
During approximately one and a half year I have been restoring a little
PDP-11/04 computer with a TU60 DECassette drive and a LA30P Decwriter. I
have followed the trail of Lou and got it to run CAPS-11 as well as
CAPS-11/BASIC.
It has been an interesting journey to repair it and actually trying to use
it give a glimpse of what it was like to develop software 40 years ago on a
minimalistic system like this. Since it only has 8kW of memory the BASIC
system uses overlays. It takes at least half a minute to load the runtime
environment when you hit the RUN command - and then half a minute to get
back to the editor again after running. Indeed patience demanding.
I put together a webpage:
http://www.datormuseum.se/computers/digital-equipment-corporation/pdp-11-04
and a short video when it runs: https://www.youtube.com/watch?v=EQsP444N5zQ
/Mattis
> I suppose that is possible, but not sure that would explain the dead stop, although I suppose it isn't impossible. I
Bad connections rarely do anything you expect :-)
> was nowhere near it when it happened. Do the signals I posted look right to you? Would you expect inconsistent
> triggering on the scope on just one of the FET outputs?
More seriously, have you tried swapping the FETs round to see if the dodgy signal goes with a particular
transistor?
-tony
> From: B Degnan
> I have one Altair turnkey (chassis only) and a bunch of DEC components
> available from a lot of computers I picked up the other day.
So I wound up with all the DEC gear from this (I gather the Altair is gone
too), but I'm not at all sure I want the System Industries hard drives. (I
assume there's at least one controller for them there, but all I know is
what's in Bill's posting. :-)
Is there anyone out there who'd be interested in them, if I decide I don't
want them? Free (basically) to a good home (although if you can't do a
pickup, we'd have to look into shipping).
Noel
> From: B Degnan
> I have one Altair turnkey (chassis only) and a bunch of DEC components
> available
It sounds like Bill's mailbox is exploding... :-) Apparently the DEC stuff
already has several people who are willing to take it.
Noel
From: Jochen Kunz <jkunz at unixag-kl.fh-kl.de>
> Similar: We had some Indigos in indogo color but with "CDC Cyber 910"
> (yes, CDC as Controll Data Corp.) printing at the Unix-AG.
Ha! Memories. I have a recycler friend who called me up one day having a
line on a st00pid number of "CDC computers" for dirt. He thought maybe he
could make a few dollars on machines from the Center for Disease Control.
I took a look and realized they were rebadged SGIs from Control Data,
workstations and servers. I hooked him up with some folks into that sort
of kink and he sold each one for about 15 times what he paid for them. I
bought a car and a really nice grill with what he kicked back to me for the
intel and the hookup. Good times.
Bob Brown wrote:
>Does anyone have experience with the hpdrive project?
I do. I use a small board NI PCI card. Like this one:
http://www.ebay.com/itm/National-Instruments-High-Performance-GPIB-interface
-for-PCI-Model-PCI-GPIB-/221231586346?pt=LH_DefaultDomain_0&hash=item33826e1
c2a
Works wonders.
>I'm wondering if the following card might work with it:
>http://www.ebay.com/itm/HP-Agilent-82350A-E2078A-PCI-GPIB-Interface-Card->/
351361191725?pt=LH_DefaultDomain_0&hash=item51cec24f2d
It won't. As you can see in the picture, it's based off the TI9914 which is
specifically excluded from the compatibility list. Search National
Instrument PCI-GPIB on eBay and there is a ton of these. The older large
ones are less expensive than the newer small ones.
Jay West wrote:
> I had read somewhere that most PCI cards did not [work].
They do. But you need an National Instrument card based off the chipsets
that Ansgar lists, because he wrote his driver for the NI chipset series. I
use the relatively recent (vintage 2002) small form factor NI GPIB PCI card.
Although he doesn't have it listed as tested, it is based off the TNT5004
chipset and works without any problems with his driver.
I have one Altair turnkey (chassis only) and a bunch of DEC components
available from a lot of computers I picked up the other day. I am looking
only to recover expenses (truck and gas) and I don't want much. These are
best for someone who has experience cleaning a "barn find" as this is where
I got these items. The real "cost" will be the time needed to take apart
these systems and clean thoroughly. I did not see evidence of any chewed
wires fortunately, just nests, some urine staining, seed storage, etc. All
of the computers were working maybe 20 years ago-ish but they have fallen
into neglect.
http://vintagecomputer.net/temp2/
Best offer for some/all, pick up only. Landenberg, PA. No I will not
deliver to VCF.
CONTACT ME HERE: http://vintagecomputer.net/contact.cfm
- PDP 11/34 #1 (no serial card but otherwise populated) *
- PDP 11/34 #2 (with Hard drives, racked, no serial card but otherwise
populated) *
- PDP 11/44 (mostly populated complete maybe) *
- Tall rack with RK05 ** and hard drive for DEC 11/34 #1
- Altair Turnkey, chassis only. *
asterisk key:
* items contains/contained a rodent nest.
** I tried but could not extend from rack, rails rusted?
NOTE - I will keep these items outside ready to be taken. They will be
tightly covered with a new tarp, the weather should be nice for a while.
That said, if you want these items held for an extended period I can't
guarantee that they'll stay dry forever. Act Now!
Bill