Formatting a 5.25" floppy disk

Try using the /f:1200 command line parameter on the format command.

Well, that is what I did back in my time on MS-DOS.

Microsoft has removed all options from the command line format command /F: parameter in Windows XP except for 1.44. I don't see any good reason for them to do this except perhaps to save money on support calls. However Windows will still read and write to other size disks that are already formatted. I struggled with this one for a while, however I found that you can format other size disks in Windows XP from the command line. The track and sector parameters are still supported! So to format a 1.2M 5.25" floppy simply type:

format A: /T:80 /N:15

You should be able to format any size disk supported by your drive and BIOS by specifying the correct track and sector count.

It depends on the OS, so I'm going to explain the way I did it on Windows XP, which cannot do it 'out of the box' (pre-XP versions all have this capability through 'format' in Command Prompt).

You need to download OmniFlop, then follow the instructions in the User Guide to replace your current floppy driver with the OmniFlop driver (you will not need the OmniFDC driver; that's only for very old, very specific data types).

Open the OmniFlop program, click 'Format Disk', choose your floppy drive (A: or B:), and select the disk type. DOS 360KB and DOS 1.2MB are the most common; these are double-density and high-density respectively. Wait for the progress bar to finish, then you're all done!