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Where can i get small toroids for magnetic core memory? Answered

I have really wanted to do this but I could never find those pesky rings!

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seanroberts
seanroberts

10 years ago

I think i am going to get: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330433810462&rvr_id=&crlp=1_263602_263622&UA=WVS%3F&GUID=bb6efd981260a0aad2c2bf02fff80f71&itemid=330433810462&ff4=263602_263622#ht_500wt_1154 This will work right? It will change states when current running through wire magnetizes it.

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steveastrouk
steveastrouk

Answer 10 years ago

Looks ideal to me.

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seanroberts
seanroberts

Answer 10 years ago

What I am worried about though is if the will change the polarity of their magnetic field in the way necessary for magnetic core memory. I don't know if cores were purpose built with specific material properties but I am hoping they weren't and that all small ferrite toroids will work.

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steveastrouk
steveastrouk

Answer 10 years ago

I'll ask my father, who is an expert on ferrite properties. Steve

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seanroberts
seanroberts

Answer 10 years ago

Thanks, that would be of great help!

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steveastrouk
steveastrouk

Answer 10 years ago

Right, I asked. "Only HARD ferrites are used for core memory - they have a virtually square BH curve. Hard ferrites exhibit permanent magnetism, soft ones don't." Steve

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steveastrouk
steveastrouk

10 years ago

If I were you, I'd look at buying some old core memory and re-energising it, rather than sewing my own. Steve

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seanroberts
seanroberts

Answer 10 years ago

I can't find old core memory either. What do you mean by re-energizing it? Do the toroids become demagnetized or something?

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steveastrouk
steveastrouk

Answer 10 years ago

http://cgi.ebay.co.uk/USSR-Soviet-military-ferrite-core-memory-HUGE-CORES-/220616557908?cmd=ViewItem&pt=LH_DefaultDomain_0&hash=item335dc58554

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Re-design
Re-design

Answer 10 years ago

Too bad that one appears to have been damaged.

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steveastrouk
steveastrouk

Answer 10 years ago

Yes, but its got cores on it. The one the same guys had sold that was intact went for over 150 USD ! That means the 4 boards I have from a computer that was broken up at University must be worth a fortune by now. Steve

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Re-design
Re-design

Answer 10 years ago

Yes, I forgot the original quest was for the cores.

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Re-design
Re-design

Answer 10 years ago

Gosh. Those are sure tiny little things. I'll bet the people sewing those things went bonkers after a while.

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steveastrouk
steveastrouk

Answer 10 years ago

According to some of the sources about the Apollo guidance computer, the core rope memory of the AGC was know as LOL memory, for Little OId Lady memory - it was hand stitched by, well, little ol d ladies who could follow a knitting pattern !

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seanroberts
seanroberts

Answer 10 years ago

Ya, I heard that on a discovery channel show about the apollo missions from someone being interviewed who actually worked on the mission.

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Re-design
Re-design

Answer 10 years ago

I had heard something very similar.

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kelseymh
kelseymh

Answer 10 years ago

Fascinating. From the picture, I calculate that they're exactly 1/33 inch in diameter (1/13 cm). That seems a slightly non-obvious form factor to choose.

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steveastrouk
steveastrouk

Answer 10 years ago

I mean make the old electronics work, the core should work forever. Steve

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Burf
Burf

10 years ago

All of the new fluorescent bulbs I've opened up have one in the circuit board. I once saw an Instructable for opening the things up. I presume it is still available through the Search function above.

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Jayefuu
Jayefuu

10 years ago

Cor that sounds like a lot of work!

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steveastrouk
steveastrouk

Answer 10 years ago

Do you mean core that sounds like a lot of work ? ! Steve

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Jayefuu
Jayefuu

Answer 10 years ago

Yes but I was being coreful not to make the pun tooooooo obvious.