Old core memory system.

[Chuck Guzis]

On 05/05/2018 10:23 AM, Pete Lancashire via cctalk wrote:
> Core temp was a big issue even in commercial environments. You didn't see
> it temp but you would see core [driver] current.

The early IBM 7000 series (7070, 7080, 7090) kept core in a
temperature-regulated oil bath.  Later versions used pre-heated air
(e.g. 7094 core).

On the CDC 7600, hitting the same area of care repeatedly could cause it
to overheat and throw parity errors.   Circuitry to detect this would
slow-down repeated accesses.

That was for CM.  I seem to recall someone telling me that there was no
such provision in PP core and a "jump to self" was sufficient to throw
an error--but that may be a shaggy-dog story.

--Chuck