Core Memory: Photographs of Vintage Computers

Core Memory
Cores are rings of ferrite suspended in a grid of wires (visible in the right third of this frame). A charge to a point on the grid magnetizes the ring in a clockwise or counter-clockwise direction, which corresponds to a one or a zero: one bit. Because it holds its state, core memory is able to retain information even when the electricity is turned off, thereby paving the way to modern computing.

• The Book: Core Memory