I am using Windows XP with an old accounting app, that will only back up to a ‘3.5 inch’ floppy disk. The backup requires a second disk to complete the job – a pain. Would an Extended Density 2880 KiB floppy (if I can find it) work in that drive?
The 2.88MB "extended density" disks have a different type of coating on them, which normal "high density" drives are not optimised to read or write. So you might not reliably be able to format it even for 1.44MB. I believe these disks were never common and are now decidedly rare, as are the drives to work with them.
A 1.44MB drive is also not designed to operate at the higher data speeds of a 2.88MB format, and a standard disk controller cannot work with the 2.88MB format either.
I'm not certain, but your accounting software might accept an LS-120 drive as a backup medium; it is also capable of handling normal floppy disks at their normal capacity. I think LS-120 might also be easier to find than 2.88MB disks and drives, as well as being vastly more capable.
I can think of several solutions
- Run the software in a virtual machine with a virtual floppy disk image attached to it
- Just change the drive letter of some partition to A: or B: since I doubt that the software actually checks the drive type and just assumes that the first 2 letters are for floppy drives
But I think migrating to some newer software is the best solution. You should migrate as soon as possible, otherwise the migration cost would be much bigger in the future, especially with some ancient software that's vulnerable to attacks like Windows XP you may have to pay some other much more painful cost