proper way to format/use floppies (i386)

[Michael Adam <openbsd_(_dot_)_org_(_at_)_googlemail_(_dot_)_com>]

Hi,

I could not tell from the documentation which is the proper way
to setup and use floppy disks on the i386 architecture, i.e. which
is the right partition to use. 
I am talking about the standard 3.5 inch 1.44 MB floppy disks.
There are several possibilities to put a file system onto one:

First of all, a floppy needs to be low level formatted, which can be
achieved by the fdformat program. (Ususally, this is not necessary
nowadays, since floppies come preformatted.)

Then fdisk shows an empty partition table.
Without adding a type a6 partition, I have a valid disklabel:

> 16 partitions:
> #      size   offset   fstype    [fsize  bsize  cpg]
>   c:   2880         0  unused        0        0         # Cyl  0 -    79

I can then do a "newfs fd0c" and afterwards the disklabel 
looks as follows:

> 16 partitions:
> #      size   offset   fstype       [fsize  bsize  cpg]
>  c:   2880         0  4.2BSD     2048  16384   80  # Cyl  0 -    79

And I can mount /dev/fd0c. But _strangely_, I can mount /dev/fd0a
as well! (But I can't do "newfs fd0a" ...)

The other way would be to add a proper partition to the disklabel:
Either by doing "disklabel -w fd0 floppy3" or by interactively
adding a partition "a" that covers the whole disk.  The first command
yields a disklabel like this:

> 16 partitions:
> #      size   offset   fstype       [fsize  bsize  cpg]
>   a:   2880         0  4.2BSD       512    4096   80  # Cyl  0 -    79
>   b:   2880         0  unused           0         0         # Cyl  0 -    79
>   c:   2880         0  unused           0         0         # Cyl  0 -    79

The second command's disklabel does not have the "b" partition.

Then, doing "newfs fd0a" or "newfs fd0c" yields a filesystem I can
mount as /dev/fd0a or /dev/fd0c in either case. The command 
"newfs fd0c" changes the disklabel to the following form though:

> 16 partitions:
> #      size   offset   fstype       [fsize  bsize  cpg]
>  a:   2880         0  4.2BSD       512    4096   80  # Cyl  0 -    79
>  b:   2880         0  unused           0         0         # Cyl  0 -    79
>  c:   2880         0  unused      2048  16384   80  # Cyl  0 -    79

which should actually be invalid since "a" and "c" overlap.
Anyway, it works and both partitions can be used.

Well, I am a little confused and would like to know which is the
proper way of handling this. I think that the proper way is to 
add an use partition "a", but I have seen usage of partition "c"
in several documentations on the web, so this is why I ask.

Thanks in advance!

Michael