[univacky]

If you had a system with only one floppy, you still had an A: and a B: drive. Any access to (virtual) B: would prompt you to insert the other floppy, and I/O would continue until the disk in A: was needed, and you'd be prompted to swap floppies again.

[scholia]

"The floppy shuffle" as we used to call it. It's why I'd never willingly buy a system with only one drive.

The floppy shuffle on the original Mac was a particular nightmare....