This is brief overview of floppy disk management in linux, with a specific
view to Fedora Core.
1. Floppy devices
Most linux systems including Fedora Core provide floppy device access
through the /dev/fd* devices files. Symlinks are traditionally created
by the device mangement part of the kernel like /dev/floppy, which
might point to /dev/fd0, the first floppy device.
A. The /dev Devices
Subsequent floppy device are then made available as /dev/fd1, /dev/fd2 and
etc. Assuming that a floppy is made available through /dev/fd0, then
it may be accessed (or formatted) at different capacities by using the
following devices:
/dev/fd0 3.5 inch standard double-sided, high-density 1440KB (1.44MB)
/dev/fd0u1440 same as fd0
/dev/fd0u1680 3.5 inch 1440KB DS-HD floppy with extra track (reliable)
/dev/fd0u1760 3.5 inch 1440KB DS-HD floppy with 2 extra tracks (reliable)
/dev/fd0u360 5.25 inch 360KB Single Sided High Density floppy
/dev/fd0u720 5.25 inch 360KB Double Sided High Density floppy
Other non-standard sizes, haven't testsed these:
/dev/fd0u800 /dev/fd0u820 /dev/fd0u830
/dev/fd0u1040 /dev/fd0u1120 /dev/fd0u1722
/dev/fd0u1743 /dev/fd0u1840 /dev/fd0u1920
B. Device detection
Check dmesg(1) or /var/log/messages for the Floppy Device. An entry in the logs
should appear if the device is detected properly and attached to a device handler.
E.g.,
bash # cat /var/log/messages|egrep -i 'floppy|fd.*[0-9]'
May 8 15:17:27 howzat kernel: ide-floppy driver 0.99.newide
May 8 15:17:28 howzat kernel: Floppy drive(s): fd0 is 1.44M
May 8 15:17:28 howzat kernel: FDC 0 is a post-1991 82077
Another way of determining if a floppy drive is properly detected by
the kernel is to use the probe feature of the floppy(1) utility:
bash $ floppy --probe
floppy 0.12 Copyright 2001, Double Precision, Inc.
floppy /dev/fd0: 3.5" HD
2. The floppy utility
Linux comes with floppy(1), a utility for managing floppy devices. The
floppy(1) command is capable of formatting, verifying and describing
capacities of floppies.
Floppy(1) uses low-level formatting calls to format floppies and because
of this the exact geometry of the disk must be specified (with the --size
option). Floppy(1) is able to print the capacity geometries for any
floppy device that it finds. However, to do this it must first be
configured.
By default, floppy(1) uses the configuration file /etc/floppy. To create
this file, use the --createrc option as follows:
bash # floppy --createrc > /etc/floppy
3. Formatting
Formatting a floppy at the standard size (1440 MB) is pretty easy. Linux
provides access to a large variety of formatable floppy devices, such
as single sided, double-sided, extra track (1680KB, 1740KB).
The linux floppy(1) utility can be used to perform low-level floppy disk
formatting. The floppy(1) tool uses a simple interface for formatting disks
in floppy controller drives and in ATAPI IDE floppy drives, such as LS-120
"Superdisk" drives. ATAPI IDE support requires a patch to the Linux kernel.
Without a patched kernel floppy can only format disks in floppy controller
drives.
A. Standard double-sided high-density 1440KB
Using floppy(1), a 1.44MB 3.5" disk can be formatted with ease. To
format a 3.5", first determine what capacities are available with:
After the format completes, check the capacity, with:
$ floppy --capacity A:
floppy 0.12 Copyright 2001, Double Precision, Inc.
Formattable capacities for /dev/fd0:
80x36x512 (/dev/fd0H1440, 1.40 Mb)
80x18x512 (/dev/fd0D720, 720 Kb)
80x48x512 (/dev/fd0u1920, 1.87 Mb)
80x28x512 (/dev/fd0u1120, 1.09 Mb)
80x40x512 (/dev/fd0u1660, 1.56 Mb)
80x26x512 (/dev/fd0u1040, 1.01 Mb)
80x46x512 (/dev/fd0u1840, 1.79 Mb)
80x42x512 (/dev/fd0u1680, 1.64 Mb)
Then format the floppy to the desired capacity by specifying the
geometry with the --size option. E.g., to format a 3.5" floppy
to standard 1.44MB capacity with FAT32 filesystem:
3.5" at 1.44MB (FAT32)
bash $ floppy --format --size=80x36x512 --fat --verify /dev/fd0
3.5" at 1.68MB (FAT32)
bash $ floppy --format --size=80x42x512 --fat --verify /dev/fd0
B. Formatting for higher capacity
Linux provides higher capacity device access through alternate /dev
devices for each floppy disk installed in the current environment. For
example the first floppy at /dev/fd0 as alternate devices /dev/fd0u1680
and etc, the second /dev/fd1u1680 and so on. There are a hugh array of
different capacity devices for floppies (see #1). See #2 (configuration)
and #3.A (capacity) above for determining device geometries.
To format a 3.5" at 1680K (1.68MB) with an ext2 filesystem
bash $ floppy --format --size="80x42x512" --ext2 --verify /dev/fd0
The floppy(1) output should be something like:
floppy 0.12 Copyright 2001, Double Precision, Inc.
Formatting 1.64 Mb... 100%
Note that if /etc/floppy is configured, then the floppy device can be
specified by either its linux dev path, as in /dev/fd0, or by is dos
drive letter like A: so that specifying /dev/fd0 or A: as the floppy
device are equivalent
C. Other formatting techniques
See also:
* superformat
* fdformat
* dd
4. ISO and binary images
A binary image (*.bin) or ISO 9660 bootable image (*.iso) can be written
to a floppy with the dd(1) command. Before writing the disk image, be sure
that the floppy being written to is not write-protected and is properly
formatted (to the same capacity as the disk image). See the section #3
on formatting.
For example, to write a 1680K disk image to a FA32 formatted floppy:
bash # floppy --format --size="80x42x512" /dev/fd0
bash # dd if=/tmp/Bering-uClibc_x.x_img_bering-uclibc-1680.bin of=/dev/fd0u1680