.. either magnetised or not magnetised ?!?
"in the 1950s, early computers used a matrix of magnetic cores, which stored bits by either being magnetised or not magnetised"
How did that work then?
I was taught that the direction of the magnetism was changed, one way for 'one' and the other for 'zero'. Still in use in the Shuttle, hence being able to read the contents of the Challenger's memory after it exploded and crashed into the sea.