Source: https://unsplash.com/

Let's stay on the subject of hardware. Have you ever heard of Differential Manchester Encoding? No?

This method from signal processing was and is used in many ways, but it plays an important role especially if you want to store digital signals in analog form on a medium like a cassette.

Yes, there used to be these things that had a long magnetic tape in them, and some people used a pencil to manually rewind them. 😂 

Unknown author Zack from https://zeninstruments.blogspot.com/ recently delved into this very topic. His goal was to add storage in the form of audio cassettes to a retro computer he built himself. 

The article competently goes into the technical details of the operation, and anyone who has had anything to do with signal processing will enjoy it. The topic is new to you? Never mind. Either way, the article is worth every minute of reading time.