Plane of core memory

Brent Hilpert bhilpert at
Thu Apr 18 04:49:44 CDT 2019

On 2019-Apr-17, at 9:47 PM, Grant Taylor via cctalk wrote:
> On 4/17/19 10:30 PM, Andrew Luke Nesbit via cctalk wrote:
>> Hello all,
> Hi,
>> I have been wanting to acquire a plane of magnetic core memory as a piece of computing history.  My partner actually thinks they look very beautiful and says we should frame it, if we ever find a plane.
> ...
>> Does anybody here have any ideas?  For example, what is it?  Or, if you don't know, could you point me in the right direction so I can do the research myself?  Thanks!!
> I have no idea.
> The connectors remind me of a DEC machine bus, but I don't know what the bus name is.  I also find it odd that memory would plug into the system bus like that.

It doesn't plug into a system bus, it would plug into a dedicated slot connected to other dedicated boards.
There's piles of circuitry necessary for it be fully functional: decoded x/y drivers, inhibit drivers, sense amplifiers, word latch, cycle sequencer.

It's a 4-wire 3D planar array. By topology and construction I would guess it date it from the 60s.
Into the 70s most (American) core production had moved on to simpler weave topologies (the crosshatch sense winding, as in this unit, was very laborious to weave),
(although it is not precluded from being from the 70s).

From an historic perspective, the 4-wire, 3D, crosshatch sense aspects go back to the original core topology,
although here the earlier physical stack for the 3rd dimension is flattened to a planar array.

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