We've got a 64K-word TX-2 core memory on display at the MIT Museum. [update - here's a link http://tinyurl.com/5mve8b]

Back in 1975/6 I was using a DEC LSI-11 that had core memory. I forget how much but it was enough to run FORTRAN.

Nerd porn!

Interesting side note: the term "core dump" came from this sort of memory: http://en.wikipedia.org/wiki/Core_dump