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