This is the inside of the core memory box showing the core stack. On the top of the core stack are two red blobs which are thermistors to measure the core memory temperature. The core memory power supply varies its output voltage based on the core temperature to ensure reliable operation. The core memory will heat up during operation.
My PDP-8/E page has more information on core memory and pictures of a core plane.
Feel free to contact me, David Gesswein email@example.com
with any questions, comments on the web site, or if you have related equipment,
documentation, software etc. you are willing to part with. I am
interested in anything PDP-8
related, computers, peripherals used with them, DEC or third party, or