Ken Shirriff on Nostr: Each tiny ring can be magnetized clockwise or counterclockwise to store a 0 or 1. ...

Each tiny ring can be magnetized clockwise or counterclockwise to store a 0 or 1. Putting a current through an X wire and a Y wire in the grid magnetizes the core where the two wires cross. Special magnetic materials ensure that the other cores are unaffected. The sense wire reads out the data.