How to make floppy image to add to dos virtual machine

[E5ten]

I'm on Mac, specifically mavericks. I keep trying to use disk utility to make a floppy image, which I add files to, and then I try to add it to my VM. But it always says
"failed to open the floppy disk file"
and then the path of the file
"could not get the storage format of the medium"
then the path again
"(VERR_NOT_SUPPORTED)"

Does anyone know how to do this correctly, or some other method of adding files to the virtual machine?

[mpack]

It needs to be a plain floppy image. No kind of compression, no repacking for another media (e.g. if you convert it to ISO then it aint a floppy image any more).

I'm afraid I can't recommend any floppy image programs for OS X as I don't use that OS.

You should also expand on what you mean by "adding it to your VM". If you try to insert a floppy into a CD drive then that will of course not work (ditto inserting a floppy image into a virtual CD drive). Did you add a floppy controller and drive to your VM?

[mpack]

p.s. The attachment contains an image of a blank floppy. You can use this as practice, to be sure you know how to attach a floppy image to a VM. Your own floppy image file should be the exact same size in bytes as this one.

[E5ten]

p.s. The attachment contains an image of a blank floppy. You can use this as practice, to be sure you know how to attach a floppy image to a VM. Your own floppy image file should be the exact same size in bytes as this one.

I know how to add the floppy image, and I was doing it through the floppy controller. Since you seem to have a blank floppy image like that, could you possibly send one that's at least two mb, hopefully bigger, that's blank, and then I can just add my files and bring it over.
Edit: Just to make sure I was doing nothing wrong involving the actual adding of the floppy to the VM, I tried it with your blank one, and it worked fine. In addition, I've done it before using the dos installation floppy images, by duplicating them, taking everything out, and putting my files in. But they cap at about 1.5 mb, and the files I need to transfer now are all slightly too large, and I haven't been able to make larger floppy images that work. So if you can, please just attach a blank floppy image that's 2+mb,

[mpack]

could you possibly send one that's at least two mb, hopefully bigger, that's blank, and then I can just add my files and bring it over.

I'm afraid not. If I did that then it couldn't be an image of a 1.44MB 3.5" floppy, and the format would not be supported by the virtual floppy controller. As I said before, a valid image will be the exact size of the blank image I gave you. As you can see, it is not 2MB.

Image sizes are not arbitrary, they must emulate something physical if you want them to be recognized by the guest OS. In fact there was an obscure 2.88MB floppy format (*), but I never had one, and don't have any images of one, and your version of DOS may not support it anyway.

(*) From memory, this format appeared in the Win9x era but was almost instantly eclipsed by writable CDs.

[socratis]

the files I need to transfer now are all slightly too large, and I haven't been able to make larger floppy images that work

As mpack told you the floppy option won't work (not easily at least). But, it might be worth to take a look at "Shared Folders/samba with DOS guest on VBox 4.1.8" in the HowTos and Tutorials » Other Guests section.

[E5ten]

I just decided to add the thing that lets me use cd-roms, so I'm just putting anything I want to bring over in isos.

[mpack]

I just decided to add the thing that lets me use cd-roms, so I'm just putting anything I want to bring over in isos.

If you're wondering why CDs would be more flexible than floppies, it's because a CD is recorded as a single long spiral track like a vinyl LP, so its length is inherently variable. Unlike a floppy, which needs to be formatted before use, at which time it is given a fixed number of concentric circular tracks (on two sides).