16 bits of magnetic core memory (click here to enlarge)

Magneic Core Memory Reborn

I've been waiting a long time to write this post so it is with great satisfaction that I finally sit down to do so.

I recently finished working on a fairly long project which I carried out jointly over the past year or so. My friend Ben had been reading about magnetic core memory and had discovered that it was possible to buy old, surplus magnetic cores on eBay. This gave him the idea that it might be fun to try to build a modern core memory module. He mentioned this idea to me and explained a bit about the technology. It wasn't long before we had agreed to take on the challenge. As far as we knew, it was going to be the first time somebody had made a core memory module for decades!

In fact this post is really just an advertisment for the real report which is hosted here. Please visit if you are interested.

It was an enormously satisfying project for a number of reasons. We learned about the physics of magnetic materials (in much greater than we needed as it happened), we learned exactly how this interesting technology works, we learned how to design PCBs, how to have them fabricated and how to reflow solder them at home and we acquired huge respect for the original inventors of the technology whose task was so much more difficult than ours. Also, importantly and despite some unexpected challenges, we were ultimately successful. Taming the analog world and building a reliable digital memory module was indeed a rewarding experience.

The original 8-bit prototype (click to enlarge)

There were quite a few stages to the project and we hope to write up the details of our project in detail in the near future. However we decided we would first write up a clear, clean report of how we think one should go about building a core memory module, rather than exactly how we did it! Furthermore we couldn't resist the temptation to publish on the 60th anniversary of the original core memory patent: May 11th, 1951. Here again is the link to our report.

The final 32-bit version (click to enlarge)

Please do get in touch with both me and with Ben if you are interested in our work.