«although the fun thing about their temperature sensitivity:
unlike bubble memory which needs to be warmed up to work, they are sensitive to temperature CHANGES, not really specific temperatures.
So while you might think that means they built a complex cooling system for it... NOPE!
IBM built systems where they kept the core memory in an oil bath that was heated, because it's easier to keep it heated at a given temperature than to cool it down to a specific temperature
so if you have an IBM 1620, it'll take up to 30 minutes to boot, because it's got to heat up all the core memory up to 106 degrees Fahrenheit (41 degrees Celsius)»