Editing Magnetic-core memory (section)

====Writing====
To write a bit of core memory, the circuitry assumes there has been a read operation and the bit is in the 0 state.

* To write a 1 bit, the selected X and Y lines are driven, with current in the opposite direction as for the read operation. As with the read, the core at the intersection of the X and Y lines changes magnetic polarity.
* To write a 0 bit, two methods can be applied. The first one is the same as reading process with current in the original direction. The second has reversed logic. To write a 0 bit, in other words, is to inhibit the writing of a 1 bit. The same amount of current is also sent through the Inhibit line. This reduces the net current flowing through the respective core to half the select current, inhibiting change of polarity.