Core memory

28-04-2024

In one of my perambulations through the internet, one subject that piqued my interest was core memory. As the name suggests, it is comprised of an array of tiny ferrite rings, with very specific magnetic characteristics, that allowed them to respond to current changes in an almost binary manner, such that only after a specific current threshold was crossed, the magnetic polarity was reversed.

Over time, core memory was replaced by flash, as core memory had a poor bit density, and for a long time, reading memory was a destructive procedure, meaning the value was "lost" and had to be rewritten, which is not time efficient, although trivial with simple logical circuits.

Naturally, not all ferrite cores are fit for the purpose of providing core memory, which I quickly realised once my AliExpress order arrived. Not only was I incredibly optimistic with my 300mA current output (even "good" ones would require something in the region of 400mA), but the ferrites themselves did not have the magnetic qualities one would require for core memory.

Thankfully, Jeff McBride compiled a number of different ferrite choices, with a purpose-built Bulgarian offering coming out on top.

The next step would be to play around with Bulgarian ferrite cores, which I plan to do as soon as some personal hiccups are taken care of.