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
