read the old 1st sector into a buffer, then overwrite the first few bytes before the BPB and the remainder after the BPB in the buffer, then write the modified buffer back to disk) or you might be able to use existing tools (specifically, the dd utility on most *nix systems).Īlso note that FAT32 doesn't make sense for floppy disks (due to the tiny size of the volume you'd want FAT12 instead).įor 1st sector of FAT32 partition (not MBR)įor partitioned disks, if you use FAT32, the first sector of the partition may contain the 1st sector of a boot loader (for BIOS, not UEFI) in addition to the BPB (required by FAT32 file system).
If you ever actually do need to write a new first sector of the disk while preserving an existing BPB then you can write a utility to do it (e.g. More often (now that floppy disks themselves are so obsolete that they effectively don't exist in practice) the floppy disk image is used directly in an emulator, or incorporated into a CD image/ISO and used for floppy emulation, where no physical floppy disk (and no "previous contents") is involved. 1440 KiB for standard 3.5 inch floppy disks) that creates a suitable BPB for that floppy disk format then copy the image into whatever floppy disks they want without caring about the floppy disk's previous contents (possibly immediately after, or as part of, formatting the floppy disk). they'll have (or write) a utility to create floppy disk image/s that are the right/desired size (e.g. There's no strict requirement from firmware or hardware for a BPB to exist and your OS can make up its own rules for what it wants.įor old floppy disks, typically an OS developer does the reverse - e.g.
Windows) will whine about the disk being unformatted if there's no BPB. Note: "should" means some operating systems (e.g. This is primarily old floppy disks and nothing else (everything else either uses partitions or a file system like ISO9660 that has different rules). The only case where the MBR "should" (see note) have a BPB is for un-partitioned disks, where the first sector of the disk is also the first sector of the file system.
0 kommentar(er)
