I’ve received several emails asking me to help modify specific types of floppy drives to record analog audio, but since all drives and taped decks are different the best I can do is explain the basic things to look for.
Enable the drive: Ground the motor pin, both select/enable pins to start the spindle motor.
Stepping the head: Tie the index pin on the connectors to the step pin.
Head direction control: Attach a switch between ground and the direction pin. This allows you to step the drive in or out.
Erasing the disk: While the spindle is turning move a strong magnet over the surface to erase the data on the disk.
Attaching the head: Try to trace the flex cable wires to one of the heads and check continuity on the pins. Attach the tape deck head wires to a pair of pins with continuity and try it out. If it doesn’t seem to work try another set of pins. I’ve also recorded audio to the disk by hooking an audio amplifier to the head.