It is damned difficult to find the means to read and rewrite what’s on a ring core memory in this millennium.... believe me, I’ve tried. Ended up assuring the enire system worked (unpowered at that) before recording the output. The technology just isn’t there any more.
You have piqued my interests. About a month ago I was looking at ring core memory on Ebay with a mind to get one and make it work.
Those rings are not ordinary ferrite. They are a special type of ferrite that has very strong hysteresis characteristics.
But what I am wondering is why you might be interested in making magnetic core memories work?