5.25" Floppy disk drive not recognized

Polytropon freebsd at edvax.de
Fri Aug 14 19:30:15 UTC 2020

On Fri, 14 Aug 2020 15:40:54 +0200, Christoph Kukulies wrote:
> Fine. There may be many solutions. Actually I’m trying to use the tools I have nd not buy extra hard- and software.
> I might also buy a used ISA-bus computer with a VGA Monitor :)
> FreeBSD always has been  a good platform to experiment at low level.
> Meanwhile I’ve proceeded a bit as can be seen in a previous post. Only this is a riddle to me:
> # dd if=/dev/fd0 of=fd_dump
> dd: /dev/fd0: Device not configured
> 0+0 records in
> 0+0 records out
> 0 bytes transferred in 0.000262 secs (0 bytes/sec)

Try with bs=512.

> Also # cat /dev/fd0 >dump
> cat: /dev/fd0: Device not configured
> Why?

That seems to be a problem with hardware formatting: The
drive does not correctly respond to drive commands, or the
medium doesn't suit the drive.

As there are many possible combinations: It looks like you
are using a "PC drive", a 5.25" 1.2 MB drive. What kind of
disks do you try to read?

I suspect some kind of incomatibility here...

> I recall there were devices like
> fd.360
> fd.1200
> fd.1440 
> or some such in earlier times where you could choose the right device.

Yes, those were present on Linux, if I remember correctly,
such as /dev/fd0.h1440 (the typical HD, high density, DS,
double sided, 3.5" disk drive).

> Also using mtools gives me similar messages:
> # mdir
> plain_io: Device not configured
> init A: could not read boot sector
> Cannot initialize 'A:'

Is the disk in the drive a MS-DOS formatted (FAT) disk?

% mdir
 Volume in drive A has no label
 Volume Serial Number is 2483-A8C1
Directory for A:/

drvspace bin     65479 1996-09-05  11:11 
command  com     96324 1996-09-05  11:11 
format   com     51111 1997-05-01  12:14 
sys      com     19143 1996-09-05  11:11
debug    exe     21162 1996-09-05  11:11 
chkdsk   exe     28976 1996-09-05  11:11 
uninstal exe     76896 1996-09-05  11:11 
       22 files             993 649 bytes
                            242 176 bytes free

If everything works correctly, you should be able to see
something like this. Furthermore, using mount_msdosfs
should work (note: for reading disks, always use -r to
avoid any kind of writing attempt).

% sudo mount -t msdosfs -o ro /dev/fd0 /media/floppy

% mount | grep floppy
/dev/fd0 on /media/floppy (msdosfs, local, read-only)

% df -h /media/floppy/
Filesystem    Size    Used   Avail Capacity  Mounted on
/dev/fd0      1.4M    1.2M    236k    83%    /media/floppy

% sudo umount /media/floppy

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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