[vcf-midatlantic] Core memory

[Dave McGuire]

On 11/26/2015 03:27 PM, william degnan via vcf-midatlantic wrote:
> Getting intermittent stuck bits with my pdp 11 non parity core stack.
> Without getting into a lot of detail, I noticed that something is causing
> the inhibit to fart high every so often, effecting address bits and to a
> lesser extent data bits.
> 
> I have been doing a lot of research.
> 
> My question.. aside from manuals and the tech docs does anyone have any
> anecdotal info, advice or test procedures related to DEC core RAM and
> intermittent stuck bits?  Shielding tips?

  I haven't had to do much repair work on PDP-11 core, but on PDP-8 core
I've found them to be somewhat sensitive to power supply voltage and
cleanliness...Ripple creeping in has caused me the problems you're
seeing on that PDP-11 core.  The other thing I've had issues with is the
temperature compensation circuit; an open thermistor has bitten me more
than once.

               -Dave

-- 
Dave McGuire, AK4HZ
New Kensington, PA