Comment Re: GCR (Score 1) 45
I kinda think most of the mechanism can be done with legos and some 3d prints for various spindle adapters. While different floppy technolgies used different track widths, you can almost always use a smaller width sensor to read a larger media width. (writing with a smaller head was a huge compatibility problem back in the day. Like DD in an HD drive.)
The magic of a teensy, rpi pico, etc can likely handle the stream of data from the head. Software can make sense of various encodings. Variable density encodings become a game of timing from the key position and fine tuning.