Using DOS Floppies with Linux

This tutorial covers the use of DOS formatted floppies with Linux. Typically a formatted floppy diskette with a filesystem requires the diskette to be mounted before use. The following commands do not require mounting of the filesystem. It is a prerequisite however that the floppy have a DOS filesystem formatted on the diskette if it is to read from or written to.

Related YoLinux Tutorials:

°Unix for DOS users

°Boot and Recovery Disk

°Integrate Linux into MS/Windows environment

°Run MS/Windows programs on Linux

°YoLinux Tutorials Index

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mdir a:	Directory listing of floppy
mdir -a a:	Directory listing including hidden files
mcopy a:dos_file   unix_file	Copy file from floppy. The inverse is also true
mcopy -t file1 file2	Handle ^M translation on text files.
mcopy -/ a: ./	Copy recursively through lower directories.
mdel a:dos_file	Delete file from floppy
mdu	List amount of remaining space on floppy.
fdformat /dev/fd0H1440 mformat a:	Format a floppy for DOS/FAT16 (2 steps)
mlabel a:label_name	Floppy label (11 char max)
mren a:file1 a:file2	Rename file on floppy.
mmd	Create directory on floppy
mrd	Rename DOS directory.
mcd	Change default directory on floppy.

The DOS floppy diskette utilities are included in the Red Hat mtools RPM.
The fdformat command is part of the util-linux RPM package.

/dev/fd	0	-	-	First Floppy Drive A:\
-	1	-	-	Second Floppy Drive B:\
-	-	d	-	Low density 5.25 in
-	-	D	-	Low density 3.5 in
-	-	h	-	High density 5.25 in
-	-	H	-	High density 3.5 in
-	-	-	360 720 1200	Capacities for 5.25 in
-	-	-	360 720 1440	Capacities for 3.5 in

Example: /dev/fd0H1440
Floppy Device drive A, high density 3.5 inch, 1.4Mb capacity.

GUI format tools: DOS or native ext2 file formats.

The pre-defined floppy configurations are specified in floppy disk parameter table in /etc/fdprm. If referring to the floppy as /dev/fd0H1440, the user has already determined the floppy density and can thus reference the device explicitly. When using the Linux device reference /dev/fd0, /dev/fd1, etc, auto-floppy device detection will determine the floppy density. Auto-detecting floppy devices (/dev/fd0, etc) can be configured with the setfdprm command.

Checking a floppy for bad blocks: /sbin/badblocks /dev/fd0H1440 1440
This will list the block numbers for all the bad blocks on the floppy.

One can also mount a floppy:

• Red Hat 6 to 9: mount -t msdos /dev/fd0 /mnt/floppy
• Fedora Core 3: mount -t msdos /dev/fd0 /media/floppy

The DOS floppy utilities (mtools) do not mount the floppy in the traditional manner but give DOS like access.

Repair bad blocks so that the blocks can be ignored and floppy can be used.

   /sbin/dosfsck -at /dev/fd0H1440

Man pages:

• mkdosfs - Create an MS-DOS file system under Linux
• dosfsck - Check and repair MS-DOS file systems
• setfdprm - Sets user-provided floppy disk parameters
• badblocks - Search a device for bad blocks
• mbadblocks - Tests a floppy disk, and marks the bad blocks in the FAT

EXT2 formatted disks:

fdformat /dev/fd0H1440
/sbin/mkfs -t ext2 -c /dev/fd0H1440

OR if badblocks:

/sbin/badblocks /dev/fd0H1440 1440 > list-of-bad-blocks.txt
/sbin/mkfs -t ext2 -l list-of-bad-blocks.txt /dev/fd0H1440

Once a floppy has been formatted and the file system is in place:

mount -t ext2 /dev/fd0 /mnt/floppy

(or for fedora Core 3: /media/floppy)

Man pages:

• tune2fs - verification based on number of times filesystem is mounted.
• debugfs (warning: It can help recover data or destroy any chance of recovering data!