Formatting a 720K floppy disk on Windows XP or newer
Bijgewerkt op: 19 jan. 2021
If you found a 720K DD floppy disk (double density) in your collection, you may find that all software made in the past few decades will expect that a 3,5 inch floppy disk is 1,44MB HD (high density). However, there's also floppy disks with the same physical size that only have 720KB of storage.
When I was trying to format the drive, I tried the following steps without success.
I tried the following command at the DOS prompt:
format a: /f:720
When I did that, here is what I got:
format a: /f:720 Insert new disk for drive A: and press ENTER when ready... The type of the file system is RAW. The new file system is FAT. Formatting 720 KB Parameters not supported by drive. Format failed.
Just like the message said, the format failed. The cover of the disk says the following:
FUJI FILM Micro Floppy Disk MF2DD Double Sided Double Density 135 TPI / 80 Tracks
Trying a standard "format A:" at the command prompt gave these results:
Insert new disk for drive A: and press ENTER when ready... The type of the file system is RAW. The new file system is FAT. Verifying 1.44M Invalid media or Track 0 bad - disk unusable. Format failed.
Still no dice unfortunately.
The I went to stackexchange to browse for solutions. And I found one solution buried away under many other suggestions. The following worked for me:
Specify the number of tracks and sectors yourself like as follows. This should be the same across most 3,5 inch 720K floppy disks.
FORMAT A: /T:80 /N:9 Insert new disk for drive A: and press ENTER when ready... The type of the file system is FAT. Verifying 720 KB Initializing the File Allocation Table (FAT)... Volume label (11 characters, ENTER for none)? CREATOR Format complete. 713.0 KB total disk space. 713.0 KB are available. 1,024 bytes in each allocation unit. 713 allocation units available on disk. 12 bits in each FAT entry. Volume Serial Number is xxxx-xxxx
Now the format proceeded completely fine, and my 720K floppy disk can be used again!