I'll add that, since I posted this article, I've switched to using a qcow2 image for the virtual floppy. It's a little smaller and qemu doesn't complain about qcow2 (qemu prints a warning if you use img files) You can use qemu-img to create a qcow2 image that's the right size (or convert an img file to qcow2 format) I use guestmount to mount it, as a general user. Either method works fine. 💾✅