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One Bit Ferrite Core Memory

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Re: One Bit Ferrite Core Memory

#3
I've never seen "live" core memory. Anyone know how it stands up to physical shock? For example, if someone accidentally bumped the rack, could it cause some of the bits to flip?

Re: One Bit Ferrite Core Memory

#4
post #3

I've never seen "live" core memory. Anyone know how it stands up to physical shock? For example, if someone accidentally bumped the rack, could it cause some of the bits to flip?

I used core memory in machines during the 1970s (primarily Data General Novas). There was no problem with physical shock, but we did get errors during strong thunderstorms.

Back then, when I was in highschool, I was told that the density of core memory was limited by the dexterity of the Filipina workers who threaded the wires through the tiny magnetic donuts.

Re: One Bit Ferrite Core Memory

#5
I know that this is entirely off-topic but I wish Google made their services a lot more visible than they are. For example I completely forgot about sites.google.com until I saw this link and the service has been there since ~2009.

Re: One Bit Ferrite Core Memory

#7
This is pretty cool by itself of course. But I'm wondering, is there any reason at all to use core memory today? I know EMP/disaster resistance has been said in the past, but a small modern durable chip encased in a bunch of protection should work better right?

Re: One Bit Ferrite Core Memory

#8
post #3

I've never seen "live" core memory. Anyone know how it stands up to physical shock? For example, if someone accidentally bumped the rack, could it cause some of the bits to flip?

For some engineering scaling reasons small things tend to be pretty tough in proportion to their size; supposedly the core arrays in the space shuttle Challenger survived ocean impact and were readable once recovered.

core was relatively sensitive to temperature and the currents had to be varied to match the temp for optimum performance. Which can be worked around as OP did by not optimizing for minimum power or minimum error rate. Also the more cores the sense wire ran thru the more temperature sensitive the core became.

Re: One Bit Ferrite Core Memory

#9

This is pretty cool by itself of course. But I'm wondering, is there any reason at all to use core memory today? I know EMP/disaster resistance has been said in the past, but a small modern durable chip encased in a bunch of protection should work better right?

There are plenty of rad hard memory solutions out there that have modern interfaces and take up no space relative to the size of core memory. Core memory is a thing of the past and shouldn't ever really be part of anyone's modern designs. You can get rad hard RAM, EEPROM, and NV Flash today for space and military applications, for a price [1]. If you want disaster-proof offline backup, a below ground water-proof storage locker bolted to the foundation with a faraday cage inside is more than enough. Dig deeper if you want it to survive a nuke.

[1] http://www.3d-plus.com/product.php?fam=8

Re: One Bit Ferrite Core Memory

#10
post #5

I know that this is entirely off-topic but I wish Google made their services a lot more visible than they are. For example I completely forgot about sites.google.com until I saw this link and the service has been there since ~2009.

https://www.google.com/intl/en/about/products/
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