As I understand it the `swop floppy` allows you to change the identities from A > B and B > A if you have two floppy drives fitted. You can do this by changing the connectors but delving inside the PC every time you want to change can be a pain. The default for swop floppy is `disabled` and only need enabling if you have two drives and want to swap them.
I am not familiar with your original problem, but presumably you could not boot from it?? If this is the case you should either set it as the first boot device in the BIOS or select it as the boot device during startup by using F8 to get to boot devices and then select it.