How did ferrite toroids store binary information in early computers?

In early computers, ferrite toroids—tiny, doughnut-shaped magnets made of magnetic ceramics—served as a primary form of nonvolatile memory. These cores were arranged in large arrays and threaded onto a two-dimensional grid of wires.123

To store binary information, the system utilized the material's ability to be magnetized in one of two stable directions, representing the binary values 0 and 1. The process functioned as follows:41

• Magnetization: Electrical currents sent through the wires intersecting a specific core would change the direction of its magnetization.32
• Binary Representation: Depending on whether the core was magnetized in a clockwise or counterclockwise direction, it represented either a 0 or a 1.2
• Data Retrieval: A third wire threaded through the cores detected their magnetic orientation. When the system sent electrical pulses to a specific array of cores to read the data, the pulses would reverse the core's magnetization, inducing an output signal that corresponded to the stored binary value.32

This technology provided extremely fast, random access to information, significantly improving upon earlier memory storage methods.32