5.25" Floppy disk drive not recognized

Lowell Gilbert freebsd-questions-local at be-well.ilk.org
Fri Aug 14 19:48:02 UTC 2020

Christoph Kukulies <kuku at kukulies.org> writes:

> 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)

Yeah, that won't work. When floppy drives were common, they were
(typically) strictly ISA devices and so sometimes required configuration
at the driver level. See fdc(4), although generally I remember being
able to do all of the magic through fdcontrol(8).

Because your media are old, they are likely to be troublesome, and
fdread(1) may save you time in getting the maximum amount of data off
the floppies. Be careful with the disks that have your precious data by
experimenting with ones you're willing to sacrifice, and don't read or
write the important ones any more than necessary.

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

Did that ever work? Looking at the driver, I'm not clear that a normal
read or write device operation was typical; it may be that you had to
use ioctl functions instead.

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

The documentation for the .mtoolsrc goes over some of the incantations
that can be needed depending on the hardware.

Also bear in mind that the cables involved can be touchy (in my
experience, because the sheathing gets brittle) and that old magnetic
media will often de-adhere from the substrate, potentially ruining the
drive heads as well as the floppy medium itself.

Good luck.

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