Some interesting projects recently to read and write floppy disks - often being multi-format capable and sometimes capable of duplicating various copy-protected images. Sometimes the documentation gives a great introduction to the low-level realities.
FluxEngine by David Given uses a cheap Cypress dev board, USB-connected to a host, and can now “write Macintosh 800kB GCR disks using a normal PC drive.”
GreaseWeazle by Kier Fraser uses Blue Pill (another STM32 ARM board)
See also previously
A Hilarious and Ingenious Disc Protection Scheme for the BBC Micro
(and further topics linked within.)