2016-09-07 17:33 GMT+02:00 Doug Ingraham :
> The most likely cause of what you are seeing is a broken wire when the
> plane was originally assembled. The wire was pulled back a few cores and
> the end stripped. New wire was soldered to old, insulated and then they
> continued threading in that w
The most likely cause of what you are seeing is a broken wire when the
plane was originally assembled. The wire was pulled back a few cores and
the end stripped. New wire was soldered to old, insulated and then they
continued threading in that wire. Over the years the solder joint has
degraded o
So what are the other options?
* Trying to repair the unit. Every plane is soldered together with the ones
nearby to convey the X/Y signals. This can probably be undone with a
patience and soldering braid. But what are the chance that the X/Y wires
gets lose then? Are those soldered or welded into
From: "Mattis Lind: Tuesday, September 06, 2016 2:11 AM
* Use a PDP-15 MM15 stack and sense/inhibit boards.
I have several off these. Adding a small backplane, put the X/Y drivers,
sense amp/inhibit drivers and level converters there and then adapt to the
existing slots for the memory module. It
>
> I'd tend to be more pessimistic about this working.
>
> There are different requirements in winding a wire for purposes of inhibit
> and sense.
> In the 3-wire arrangement the winding of the combined wire has to meet both
> sets of requirements.
>
> Specifically, for this case, in a 4-wire mem,
On 09/05/2016 09:28 PM, Brent Hilpert wrote:
I'd tend to be more pessimistic about this working.
In the 3-wire example there you can see how the S/I wire was split in half with
a special resistor network at one end to allow inhibit current flow
while at the same time configuring it as a balan
On 2016-Sep-05, at 4:36 PM, Jon Elson wrote:
> On 09/05/2016 05:46 PM, Mattis Lind wrote:
>> måndag 5 september 2016 skrev Jon Elson :
>>
>>> On 09/05/2016 01:59 PM, Mattis Lind wrote:
>>>
I have now concluded that the fault is in the core memory module itself.
The sense winding is brok
On 09/05/2016 05:46 PM, Mattis Lind wrote:
måndag 5 september 2016 skrev Jon Elson :
On 09/05/2016 01:59 PM, Mattis Lind wrote:
I have now concluded that the fault is in the core memory module itself.
The sense winding is broken on bit plane 7.
Have you actually ohmed out the sense/inhibit
måndag 5 september 2016 skrev Jon Elson :
> On 09/05/2016 01:59 PM, Mattis Lind wrote:
>
>>
>> I have now concluded that the fault is in the core memory module itself.
>> The sense winding is broken on bit plane 7.
>>
>>
>> Have you actually ohmed out the sense/inhibit wire?
>
This is by the way
On 09/05/2016 05:26 PM, Mattis Lind wrote:
måndag 5 september 2016 skrev Jon Elson :
On 09/05/2016 01:59 PM, Mattis Lind wrote:
I have now concluded that the fault is in the core memory module itself.
The sense winding is broken on bit plane 7.
Have you actually ohmed out the sense/inhibit
måndag 5 september 2016 skrev Jon Elson :
> On 09/05/2016 01:59 PM, Mattis Lind wrote:
>
>>
>> I have now concluded that the fault is in the core memory module itself.
>> The sense winding is broken on bit plane 7.
>>
>>
>> Have you actually ohmed out the sense/inhibit wire?
Yes. I have measured
On 09/05/2016 01:59 PM, Mattis Lind wrote:
I have now concluded that the fault is in the core memory module itself.
The sense winding is broken on bit plane 7.
Have you actually ohmed out the sense/inhibit wire? There
were some very old memories that had some kind of
metallurgical problem w
For some time I have slowly been working on restoring our PDP-8 to
operating condition.
Here are some notes on the progress:
http://www.datormuseum.se/computers/digital-equipment-corporation/pdp-8
It is sort of working now after reforming capacitors in the PSU, adjusting
memory currents and repla
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