fedora core 4: no fd0u1680?

[fedoralist at subtropolix.org]

Jeff Vian wrote:
> On Sat, 2006-09-30 at 00:23 -0400, fedoralist at subtropolix.org wrote:
> 
>>Jeff Vian wrote:
>>
>>>On Fri, 2006-09-29 at 17:24 -0400, fedoralist at subtropolix.org wrote:
>>>
>>>
>>>>Joe Smith wrote:
>>>>
>>>>
>>>>>fedoralist at subtropolix.org wrote:
>>>>>
>>>>>
>>>>>
>>>>>>I've been using core 4 for quite some time now and this is the first 
>>>>>>time i've had to think about device nodes. I'd like to mount a floppy 
>>>>>>that's formatted to 1680 density but can't figure out how the device 
>>>>>>nodes work. ...
>>>>>
>>>>>
>>>>>I hate to ask, but did you try it? The fd0...fdn devices are supposed to 
>>>>>auto-detect the actual capacity and density of the disk in the drive.
>>>>
>>>>Yup. After reading the udev stuff.
>>>>
>>>>[root at apollo ~]# mount -t vfat /dev/fd0 /media/floppy/
>>>>[root at apollo ~]# ls /media/floppy/
>>>>?.?           8v??.??       fp??????.?1?  ??syslin.ux   ???.u??
>>>>????????.???  }???.?b?      f?>?tf??.t??  ????????.?t?  ???}????.u}?
>>>>?.??>         ??b?6?t?.???  f!?txf?.?     ???????.t?=   ???????u
>>>>?<??@???.???  b??????u.???  ???h.???      ?????!?t.?aq  u????u?.???
>>>>???.???       ??cbt.^?f     ?>lu.?hu      &?tf??4u.?.?  _w??p??.??_
>>>>??.???        dlinux s.ys?  pamsu7f?.>du   ?t??< v.?n?
>>>>0uf???8u.f)?  f??bss.???    p??s??.???    t??x?.??x
>>>>
>>>
>>>The 1680 density is NOT a dos/vfat format.  IIRC that is a MAC format
>>>and needs to be mounted as such for proper access.
>>>
>>>
>>
>>Not true. In fact, Microsoft used to use 1680 density for its install 
>>disks. I've no idea if it was ever used for Macs, though. In any case, 
>>it mounts fine on core 3 with -t vfat.
>>
> 
> I dimly remember that Win95 (the last version that did a floppy install)
> had higher than standard density diskettes for the install.  I never did
> know exactly what density it was, and the floppy install for windows
> disappeared after that use.
> 
> 
>>The example i posted above was to show that the disk was not 
>>automagically detected by udev as 1680. That is what i would expect to 
>>see on my core 3 box if i used /dev/fd0 (because it's the wrong density).
>>
>>core 3:
>>[root at poseidon ~]# mount -t vfat /dev/fd0u1680 /media/floppy/
>>
>>works fine.
>>
>>core 4:
>>[root at apollo ~]# mount -t vfat /dev/fd0u1680 /media/floppy/
>>mount: special device /dev/fd0u1680 does not exist
>>
> 
> With Core 3 and earlier all the possible device types were created
> in /dev.  In later releases they saw fit to remove them and they now
> have udev and hal to do the automatic configuration for you.
> 
> I bet if there was a rule for udev to create the device you could get it
> to mount under FC4 & FC5.
> 

OK, i've come across this page:

http://www.kernel.org/pub/linux/utils/kernel/hotplug/udev.html

I'm wading through it now, but it's pretty opaque to me. What i'm trying 
to figure out is whether or not /sbin/hotplug can tell that the disk is 
at a higher density. Understandably, there's not a whole lot about 
floppies in any of the udev/hotplug docs i've seen.

And i've been poking around in /etc/udev & /etc/dev.d but haven't yet 
figured out how this should work.

> Alternatively, if you know the specific characteristics of the device
> you could use mknod to create it manually.
> 

Yeah, i can do that, though i'd have to take measures to ensure udev 
didn't disappear the node on reboot. In any case, i'm somewhat without 
clue as to the major & minor numbers required.

Still working on it ....