Did anyone ever succeed in repairing a stepper motor
Currently restoring a datapoint floppy drive that has been stored in a disastrous environment.
The head stepper has a loose wire, currently I cannot even see how to open the stepper motor.
It is a Warner Electric SM-024-0045-AS
Cannot see any marking as to who the druive supplier is, it might have been Datapoint themselves.
Jos
Anyone have one of these single board embedded computers in use? I have
one that is unresponsive and I believe I need to replace the Dallas battery
chip, similar to other computers like the SunSparc 10 that does nothing
without a working NVRAM battery chip installed.
Any opinions/experience with this card out there? I have already ordered a
new battery but while I wait I'd like to throw this one out there. Its from
the later 90's not yet "vintage" so that's why the header semi OT.
http://www.voxtechnologies.com/SBCs/pdf/icp/rocky-518hv-ver4-0.pdf
Bill
Seeing Noel's blinkenlights project and list of panels, for interest's sake here is a picture and
decription of the Foxboro drum indicator panel from one of the hardware manuals.
http://web.aanet.com.au/~malikoff/foxboro/FOXBORO_Drum_indicator_panel_1.jpghttp://web.aanet.com.au/~malikoff/foxboro/FOXBORO_Drum_indicator_panel_2.jpg
There was no trace of any panel nor drum when I recovered the Foxboro 2/10 (PDP-11/15) but I did
find the print set for the above panel (schematics only, no panel hardware details), and a set of
RC11 modules (6 flip chips) wrapped with an error list printout. I'm not even sure if there was a
drum fitted, as none of the notes I found for the actual installation mention it.
There was no other drive in the rack when I got there, so I'm baffled as to what device the cards
went to.
Steve.
> From: David Bridgham
> I could ask for a lot more really but that's pretty good.
IMO we're 'over the hump' on the prototype phase of the project. The complete
QBUS interface (including DMA and interrupts) are done, and very thoroughly
tested, and now we have the SD interface up and running too. Once we get all
this running reliably, IMO the remaining work (configuration, simulating the
RP11, etc) will be relatively simple and straightforward.
Then we get to the next major lump - turning out the production unit.
> Here's a picture to my test setup:
Looking at that brings up another piece of progress to report; that paper
version of the indicator panel inlay is just about obsolete; we have produced
blank inlays (the correct shape to fit into the bezel, but with just the back
black layer with all the holes), and the next move is to produce ones with
the white captions silk-screened on the front, just like the originals:
http://ana-3.lcs.mit.edu/~jnc/tech/DECIndicatorPanels.html
So 'very soon' we should have a complete working indicator panel!
A lot slower, overall, than we had hoped, but we're getting there!
Noel
I had that happening on mine.. came down to a bad RAM board.
Sent from my Samsung device
-------- Original message --------
From: Nick Allen via cctalk <cctalk at classiccmp.org>
Date: 2018-01-01 10:32 AM (GMT-08:00)
To: cctalk at classiccmp.org
Subject: Help diagnosing boot issue SWTPC 6800
Hey everyone, Happy New Years!? I am thankful for an active community
that enjoys helping each other learn, and today I am coming with an ask
for help.
I have a SWTPC 6800 and ADM3A terminal, I can get it to boot, and when
it boots it will continue to boot for several hours.? But getting it to
successfully boot takes upwards of 100 power OFF and ON cycles.? The
other 99 times, I get a continuous stream of random ASCII characters
(see video link below).? It's my first time seeing this type of issue
that happens intermittently, and wondering if anyone has any insights in
what might be causing this.? I suspect its a faulty IC on the Processor
board that resets or controls the OS reset, will need to deep dive and
diagnose, but thought I would ask for some direction first.
https://www.youtube.com/watch?v=Ci4vhPn-3PE
Thanks in advance!
-Nick
> From: Peter Corlett
> since we have computers with multiple gigabytes of RAM, it makes little
> sense to restrain one's use of them to a fraction of the capabilities,
> except as an intellectual exercise.
For data, sure. (It's amazing how big even images can become, as the
resolution is increased. And that's not even video!)
For code, however, there are very good reasons to think that 'more is _NOT_
better'. More code means more complexity, and that has a host of Really Bad
consequences: harder to understand, more likely to have bugs, etc, etc.
It also often means that unless you have the Latest and Greatest hardware,
the machine is simply too slow to run the latest bloatware. The machine I'm
typing this on has a 1.4GHz single-core CPU, and _most_ things run on it just
fine - but going to many Web sites is now painful, since the 'obligatory'
HTTPS (another hot button, one I'll refrain from hitting right now, to keep
the length of this down) makes even simple Web operations slow.
Noel
So, I've been making wooden racks to hold a lot of my DEC boards, and I've
finally come up with a nice design for one, which holds quad boards:
http://ana-3.lcs.mit.edu/~jnc/tech/jpg/QuadRack.jpg
which holds them vertically.
It's much better than the dual rack next to it, which holds them
horizontally, which has the issue that the distance between the sides needs
to be absolutely perfect, otherwise the boards tend to drop out of their
slots. With the boards held vertically, it's much less sensitive.
If anyone's interested in building one, I can whip up a drawing. (Note that
the slots are offset slightly to the left because one needs different
clearances for the solder and component sides.)
The one shown uses 3 pieces of 1"x8"x6' (not sure what that translates to in
that new-fangled French stuff :-). It would be tricky to make without a
radial-arm saw, though - although I suppose a router with a small bit could
be used, albeit tedious.
Noel
> From: Michael Zahorik
> a dozen or so spare boards for my PDP8E. I was wondering about how to
> store them. Some guys recommend some poly bags, others say it is
> important to protect against humidity. ... have you had any failures
> while in storage?
Well, i) most of my boards had been in uncertain storage for a long time
before they got to me, and I've only tested a fraction of them, so if I tried
one now, and it had an issue, I wouldn't know when (i.e. under which storage
regime) it happened - some have shown failures, but I think they all happened
before they got to me; ii) some of the failures we see (e.g. PROM's losing
their programming) are known to happen via various time-related processes,
not storage condition; and iii) I'm not a hardware person, but even then,
you'd want someone with expertise in failures, which is not common.
But, having said that, these are my 'common-sense' rules for storage: i) bags
aren't critical (especially for older stuff, which is generally bipolar, not
CMOS, and therefore not very sensitive to static), ii) high humidity is not
good, as you can get corrosion on chip leads (I've seen a few where the leads
were so corroded they came off)- but very low humidity can be an issue, if
you have CMOS, as it's more static-friendly (as Dave Bridgham found out the
hard way in his lab); iii) large-amplitude temperature cycles are not good,
as thermally-induced contraction and expansion probably aren't good; and
avoiding very high, and very low temperatures (even if constant) is probably
better for long-term health.
Noel
Hello,
With the wonderful help of many you here I have revived a PDP11/04,
connected it to an RL02, and using PDP11GUI I have successfully imaged a
number of RL02 packs.? I found a copy of an RQ device that boots.? I can
attach my images and explore the contents with PIP so I believe the
transfer was good.
One of the packs was a system disk so I tried to boot it like this:
?? PDP-11 simulator V3.8-2 (JH stdio telnet)
?? sim> set cpu 11/93, 4M
?? Disabling CR
?? Disabling RK
?? Disabling HK
?? Disabling TM
?? sim> set cpu idle
?? sim> set rl0 rl02
?? sim> attach rl0 RSX11-bu.rl02
?? sim> b rl0
?? SAV -- SOFTWARE CONFIGURED FOR ENABLE HARDWARE WHICH DOES NOT
RESPOND.? HALTED.
?? HALT instruction, PC: 126272 (BR 126270)
?? sim>
Does anyone have any hints on how I can guess what I need to add? The
original machine was and 11/34 (maybe a 11/34a) and had a multi-line
serial port setup.? All thoughts appreciated.
Sincerely,
John Welch
:qw
Hi,
I was working 1976 as a volunteer at a research center near Vienna in
Austria writing FORTRAN programs on a PDP8a. We also have a PDP8/e there.
Now I am collecting DEC stuff.
Happy new year !!!!!!!!!!!!
Gerhard
-----Urspr?ngliche Nachricht-----
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Gesendet: Sonntag, 31. Dezember 2017 19:00
An: cctalk at classiccmp.org
Betreff: cctalk Digest, Vol 39, Issue 30
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