the idea was simple enough, take the obviously corroded floppy disk that came from a Roland HP-1900 and grab all the useful parts from it. the floppy disk drive is a simple device. it uses a stepper motor to position a read/write head that moves across a spinning disc made of mylar powered by a unique motor.
from a personal computer point of view there there only 3 sizes of floppy disk in common use: 8″, 5.25″ and 3.5″. smaller sized floppy disks emerged late in the game which got used for things like music players and cameras. but these formats never found a foot hold in computing.