[ErsatzVerkehr]

I thought this was interesting (both that the space shuttle still used core memory, and that the challenger memory was retrieved and its contents recovered):

> Core memory is non-volatile storage—it can retain its contents indefinitely without power. It is also relatively unaffected by EMP and radiation. ... For example, the Space Shuttle flight computers initially used core memory, which preserved the contents of memory even through the Challenger's disintegration and subsequent plunge into the sea in 1986.

(From http://en.wikipedia.org/wiki/Magnetic-core_memory#Physical_c... )

Note that this core memory is a little different than the rope core memory described in the linked article.

[adrianhoward]

My dad was a draftsman, and worked on everything from conveyer belt systems to satellite test rigs. This was in the years before CAD and he often brought A1 and A0 paper home from work for us kids to scribble on.

One time I can remember getting this sheet with this wonderful crossed-grid with rings pattern. I remember staring at it for a good ten minutes before turning it over and trying to draw spider-man ;-)

It was several year before I realised that I was looking at a drawing of core store.

One of my life regrets was that I didn't know to save it. I'd love to have it on the wall framed now ;)

[dfox]

Difference between core memory and rope core memory is that core memory has regular pattern and information is stored in magnetization of the cores, core rope memory on the other hand is read only and information is stored in it's pattern (it's essentially same thing as semiconductor-based ROM, only with little transformers instead of diodes).

[leoc]

That would be the https://en.wikipedia.org/wiki/IBM_AP-101 , I believe.

[robomartin]

I have a 1K x 8 core memory card framed and hanging on the wall with an 8x magnifying glass in front of it. People love to look at it. Then they learn their iPhone has the equivalent of 16 to 32 million of those. Mind-blowing, every time.