Magnetic core memory USB drive transfers files in sneakernet first — text and image files get moved between PCs via hugely constrained archaic memory tech

A homebrew dinner-plate-sized magnetic core memory USB storage device has been used to transfer a text file from one PC to another for the first time. In what is “maybe the world’s first” [machine translation] Japanese researcher @dydt_Nao indicates they successfully used their retro-modern flash drive as a sneakernet device. We covered this space science researcher’s earlier efforts to rekindle this archaic computer memory tech back in February of this year.

Back in February we noted that this USB flash drive had some severe shortcomings, but was nonetheless an effort that we warmly applauded. There were three key drawbacks to this ungainly USB flash drive. Firstly, it is rather massive, and it looks roughly a foot (30cm) square. Secondly, by contrast, its storage is incredibly tiny at just 128 bytes (not GB, MB, or even KB). Lastly, according to our understanding of the technology, the data stored gets erased during the read process.

In the tweet-embedded video we get to see the unnamed USB Type-A gadget work its magic. Interestingly, as data is read to/from @dydt_Nao’s device, LEDs in an attached 32 x 32 array glow a vivid red. Every LED corresponds to an individual magnetic core. We see Windows reporting the drive as having a 6.5KB capacity, but that is likely something to do with the Raspberry Pi Pico being used as an onboard controller. Towards the end of the video we get to see that the text has been successfully transferred from the drive to Notepad.

Not content with a mere text demo, @dydt_Nao follows up with a BMP image transfer. Monochrome bitmaps up to 32 x 28 pixels can be stored on this device. Perhaps a little of the limited device memory space (32 x 4) is used up by the image file header.

You can read more about magnetic core memory in our article commemorating the 75th anniversary of its patent filing by inventor and MIT electrical engineer Jay Forrester. Magnetic core memory earned its place as the dominant form of random-access storage in digital computers for two decades. Today it seems like a bizarre curiosity.