Credits (important if you are a lawyer)

This is a Stack Exchange post. Visit it at https://superuser.com/a/342436/1141594

End credits

Well, I am sorry that I am posting non-programming stuff on repl.it, but I am tech-savvy.

The image is not something funny like a jpeg or png.

Now, here is the tutorial:

Create a floppy disk image

Linux:

fallocate -l 1474560 myimage.vfd

Linux & other Unix-like systems:

head -c 1474560 /dev/zero > myimage.vfd

Windows:

fsutil file createnew myimage.vfd 1474560

You'll have an empty "1.44 MB" image. Attach it to VirtualBox and format through "My Computer" in the guest.

If you want to format the image on the host system or to copy files into it, use mkfs.vfat + mount -o loop on Linux, and VFD on Windows. Note that official build of VFD "works only on 32 bit systems" as of version 2.1, but there are alternative builds available.

Linux:

mkfs.vfat myimage.vfd
sudo mount -o loop myimage.vfd /mnt
...
sudo umount /mnt

Windows:

vfd open 0: myimage.vfd
vfd format 0:
...
vfd close 0:

Windows, create, format and mount in one command:

vfd open 0: myimage.vfd /new /1.44