The linked article shows the "standard" pinout for a 3.5" floppy drive, and it's clear the interface is below the level of anything like DMA. I assume even if

The linked article shows the "standard" pinout for a 3.5" floppy drive, and it's clear the interface is below the level of anything like DMA. I assume even if you were using something that looked like a standard floppy drive, it was using a higher level interface, or was including something like the controller ISA board in the "interface".