[TUHS] core

[Doug McIlroy]

> jay forrester first described an invention called core memory in a lab
notebook 69 years ago today.

Core memory wiped out competing technologies (Williams tube, mercury
delay line, etc) almost instantly and ruled for over twent years. Yet
late in his life Forrester told me that the Whirlwind-connected
invention he was most proud of was marginal testing: running the
voltage up and down once a day to cause shaky vacuum tubes to
fail during scheduled maintenance rather than randomly during
operation. And indeed Wirlwind racked up a notable record of
reliability.

Doug