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Re: Core memory
- To: KellySt@aol.com, kgstar@most.magec.com, stevev@efn.org, jim@bogie2.bio.purdue.edu, zkulpa@zmit1.ippt.gov.pl, hous0042@maroon.tc.umn.edu, rddesign@wolfenet.com, David@InterWorld.com, lparker@destin.gulfnet.com, bmansur@oc.edu, DotarSojat@aol.com
- Subject: Re: Core memory
- From: T.L.G.vanderLinden@student.utwente.nl (Timothy van der Linden)
- Date: Tue, 12 Mar 1996 23:14:20 +0100
>Timothy van der Linden writes:
> > > > Why doesn't the magnetic field in the ferrite core degrade? (I
assume the
> > > > ferrite has some resistance.)
> > >
> > >Have you ever known other magnets to degrade? Once magnetized, a
> > >material won't demagnetize unless exposed to heat above its Curie point
> > >or another sufficiently strong magnetic field.
> >
> > Oh, now I understand, you create a permanent magnetic field just like
> > magnetic discs and tapes. (I though you created a current in the core) So in
> > fact the cores don't need to be closed completely.
> >
> > Tim
>
>The core is in essence just a lump of magnetizable material; they were
>generally made toroidal because it was easiest to string them that way.
Hmmm, I would think that an open loop would be easier. After cross-wiring
the grid, you could simply "clip" the "cores" over the cross-sections. This
in contrast to the weaving. Anyway, its clear.
>There were some designs for magnetic memory that didn't use cores, but
>(if I recall correctly) used spots of magnetic material sandwiched
>between two layers of parallel conductors. And even more exotic memory
>hardware has existed -- ever heard of mecury delay lines? Williams
>tubes?
Nope, never heard of.
Thank you for explaining.
Timothy