Quick question: I'm going through my old cables looking for the paddle
interface for the Current loop for my pdp8/L. I thought I saved one from
my old pdp8/I, maybe not.
Regardless, I found a M857 board with a RS232 cable on it and BC01R-25
on it. Was that for a pdp11/05 by chance?
Oddly enough I also found the interface adapter that goes into my VT52
to support 20ma current loop devices. I currently use the VT52 as an
RS232 console for my pdp11, but still, Wow.
> From: Jonathan Chapman
> Last one that went auction-style on eBay went for $1,178.00
When was that?
Do you have any details of the machine's config?
That's a pretty good deal for a 780 (IMO).
Noel
> From: Chris Zach
> a M857 board with a RS232 cable on it and BC01R-25 on it.
Anyone know what an M857 is? I guess it might be a DF11 async answer mode? I
found this:
https://www.computerhistory.org/collections/catalog/102731577
but I think the number there is wrong; I'm not sure exactly which KL10 board
is an 'MBOX Control 3' - it might be the M9537.
> From:Ethan Dicks
> Sounds like it was a generic cable that probably worked with several
> devices.
Yeah, the BC01-R was used with an M957/M970 header card (not sure what the
difference between them is) in the DF11:
https://gunkies.org/wiki/DF11_Communications_Line_Adapter
Not sure where else.
Noel
At 07:50 PM 1/01/2022 +0000, you wrote:
>>
>True. But if you're trying to get > $5000 for something, it doesn't seem unreasonable to suggest that investing a bit in getting an extension cord run to the location of the machine would be a good idea. The absence of that effort makes me wonder if the owner knows what the outcome of such a test would be and doesn't want to have to report it.
>>
>
>But what would that accomplish? I think testing something like this requires a lot more effort than plugging it in and hitting the circuit breaker. To test this to see if some ODT comes up probably requires quite a lot of effort (locate a terminal/pc, wire it up, figure out where to plug it into the 780, etc. If this guy is a bulk dealer I would be surprised if he has the knowledge to do anything more than a power test which, again, would not be very useful and could even be detrimental.
Exactly. The machine has a 3-phase 208/240V plug, they don't have such an outlet. Their efforts stop right there.
But you're all focussed on that, and missing another important detail. The machine has a liquid cooling system.
Some of the hoses look like they are Tygon, in the age-decayed brittle stage. Touch them and they crumble away.
Running the machine without cooling would utterly wreck it. Even if they solved the mains power problem,
they would be very unwise to actually power it up.
The 'installation and configuration' manual for this machine would be huge. They don't have it.
Plus, it's a mainframe. Not even any blinkenlights. Without setting it up as a complete system
with everything interconnected properly, how would you even know it was running correctly?
Plus you can safely assume at least some of the system unit interconnect cables are missing.
Potentially weeks, even months of restoration work for a buyer, before even daring to apply power.
Then if there's anything wrong in the electronics, good luck diagnosing and getting spare parts.
Considering the uncertainties plus high transport, restoration, operating and manhour costs, who'd
buy it? A museum perhaps? Or someone wanting a 'static display object' never intending to run it.
Guy
Chris Zach <cz at alembic.crystel.com> wrote:
> Jesus. How much does the 11/44 chassis weigh?
>
> On 12/30/2021 3:39 PM, Alan Frisbie via cctalk wrote:
>
>> 2. 30-pound struts are not strong enough.? They improved things a bit,
>> but it still takes a lot of effort to raise the box.? I have ordered a
>> pair of 50-pound struts and will post an update when they arrive (next
>> week).
The box itself weighs about 75 pounds, plus the weight of the cards.
Remember, however, that the struts are not doing a simple lift of
the box. The box is acting as a lever. The box is 24" long, and the
struts are only about 5" from the pivot. Also, the struts are not
doing a straight lift from directly below their attachment to the box,
but at a point about 11" forward from where they are attached to the
box. All of this greatly magnifies the force required to tilt the box
up. Anyone care to do the math on this?
Alan Frisbie
Hello All,
Following a discussion on resurrecting a PDP 11/45 I have started looking at
the regulator bricks in the PSU. I have started with a H744. I reformed the
three big capacitors, although they seemed to be fine as they charged up
>from my DC bench PSU and then had zero leakage so I didn't reform them for
very long. I then moved on to powering the whole unit from my DC bench PSU
and it seemed to run fine. I am using a panel mount 1R resistor, so drawing
5A of the rated 25A. It drew just under 2A from the PSU which was set at
20V. I didn't run it for very long as I wasn't sure how hot to allow the
load to get.
Is there any sense in measuring ripple when powering this from DC? There
does seem to be some ripple:
https://rjarratt.files.wordpress.com/2021/12/h744-ripple.png hard to say if
that is OK?
Also, the indicator light does not work (as expected). I have seen the
suggestion to replace it with a CM7381. It looks like these can be sourced
<https://www.mouser.co.uk/ProductDetail/?qs=N8%2Bk0S5zvCZ7dMEMH2XU9Q%3D%3D>
with relative ease, but I wondered if there might be a better LED-based
longer term solution? I was also advised that OL-6003BP is good for the 15V
regulators, but these seem to be hard to find, any suggestions there?
Thanks
Rob
Mark J. Blair <nf6x at nf6x.net> wrote:
> When I need gas struts and cannot identify a source for exact original
> replacements, I usually look at McMaster-Carr first:
> https://www.mcmaster.com/gas-struts/
Thanks for the McMaster-Carr suggestion, I should have thought of that.
I removed the gas struts from my PDP-11/44 and found the following
markings:
Gas Spring Corp.
Colmar, PA
1216166-0-0
22/81/3 (the "1" might be an "I")
I measured them, and found a compressed length of about 9.8" and an
extended length of 15.25". The threaded studs are 5/16"-24.
I can't find the company, and Google turns up nothing with either
of the number strings. Nor do the numbers seem to indicate what
the specifications might be. Perhaps someone with better Google
skills than I have might find something.
It is, however, an almost perfect match for McMaster-Carr P/N 4138T55.
The big unknown is the extension force. After cleaning and oiling them,
one of the bad ones measures about 12 pounds, and the other is about 23
pounds. The 4138T55 is available in 15, 20, 30, 40, 50, 60, 90, and
120 pounds.
I made a wild random guess and ordered two of the 30 pound struts,
which should be delivered Wednesday (12/29/2021). The 40 pound
ones have a seven week lead time, and a pair of 50 pound ones seem
way too high. When they arrive, I'll let you know how well they work.
Worst case, I will have wasted $20.29 each, plus shipping, and have
to wait seven weeks for the 40 pound units, or go whole hog and try
the 50 pound ones.
Thanks for the help and suggestions.
Alan Frisbie
Hi
I've been using this adress for many years: "pontus at update.uu.se". But
the club is now at risk of loosing the domain name. I'm therefore moving
over to "pontus at dfupdate.se"
Sorry if this is of topic but I have made many acquaintances on this
list that might not find out otherwise.
Regards,
Pontus.
Hi
I've been using this adress for many years: "pontus at update.uu.se". But
the club is now at risk of loosing the domain name. I'm therefore moving
over to "pontus at dfupdate.se"
Sorry if this is of topic but I have made many acquaintances on this
list that might not find out otherwise.
Regards,
Pontus.
Hi ccTalk!
My name is Ryan and I may have been in contact with a few of you already (Rich, most notably) about this topic. I am on a pretty wide search of any versions of 86-DOS, or any information regarding it.
As of now, I have 7 copies of 86-DOS. They cover a disappointing range of versions ? from 1.00 to 1.14. There are a lot of duplicates. Versions prior to 1.00 were sold ? for example, I know of 2 collectors with versions in the 0.3x range, but both are unable to image it due to technical limitations.
I?ve already contacted quite a few people. Most interestingly are 5 former Seattle Computer Products employees, as well as 2 family members of SCP owner Rod Brock. Tim Paterson, the creator of 86-DOS, didn?t have a copy, nor its source code. Pat Opalka, who contributed a bug fix, is in possession of a few copies, though none are prior to 1.00 (he may or may not be able to image them ? if he does, I?ll send another message here). 3 other employees didn?t have any documents from the time, nor any copies of the software. The 2 family members of Rod Brock don?t have any copies, but have relevant documents and recordings that they are in the process of sending over.
So, if you have any copies of 86-DOS, even if you don?t want to share or its version is 1.00 or above, please send an e-mail back. I can send over imaging instructions. It was sold with the following computers:
- Seattle Computer Products 8086 System
- Seattle Computer Products Gazelle
- Lomas Data Products LDP88
- Lomas Data Products LDP1
- Lomas Data Products LDP2
There are 8? copies for Tarbell and Cromemco floppy disk controllers, as well as 5.25? copies for NorthStar disk controllers.
I will also take other relevant things such as people to contact, manuals, recollections of versions you may have had, etc.
Thank you all for your time!
- Ryan Ottignon
