5.25" Floppy disk drive not recognized

[Polytropon]

On Fri, 14 Aug 2020 15:47:47 -0400, Lowell Gilbert wrote:
> 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).

The use of fdcontrol is very important if the disk in question
is not what the drive thinks it should be. :-)



> 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.

There are also forensic tools like ddrescue (or dd_rescue?) that
can adjust retries and read block size (default from 512 bytes
down to 1 byte per try) if it needs to be.



> 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 make sure the drive is clean, the head is undamaged.



> > Also # cat /dev/fd0 >dump
> > cat: /dev/fd0: Device not configured
> >
> > Why?
> 
> Did that ever work?

More or less (in this case, less, which is more, couldn't resist):

	% less -f /dev/fd0
	ë<<90>MSWIN4.1^@^B^A^A^@^Bà^@@^Kð
	^@^R^@^B^@^@^@^@^@^@^@^@^@^@^@)Á¨<83>
	$           FAT12   ú3
	[...]

And so on. You can use cat with something like this:

	% cat /dev/fd0 | xxd
	0000000: eb3c 904d 5357 494e 342e 3100 0201 0100  .<.MSWIN4.1.....
	0000010: 02e0 0040 0bf0 0900 1200 0200 0000 0000  ... at ............
	0000020: 0000 0000 0000 29c1 a883 2420 2020 2020  ......)...$     
	0000030: 2020 2020 2020 4641 5431 3220 2020 fa33        FAT12   .3
	0000040: c98e d1bc fc7b 1607 bd78 00c5 7600 1e56  .....{...x..v..V
	[...]

In the past, I've even used tar directly with floppies, with
aliases called "flop <file(s)>" and "unflop"... :-)





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