Subject: floppy names

From: Paul Richards <[email-masked]>
Date: Sun, 5 Apr 92 16:53:40 WET DST

I've obviously missed something fundamental but I don't see why we need
device specific names. Why can't we just have /dev/fpx where x is a
number or letter or whatever. There's only one device driver for floppy
disks and I can't see why this would be likely to change. Surely we
should differentiate between drivers and not different types of
underlying hardware. 

If there are large numbers of different names for floppies then writing
portable software for them is going to be a nightmare since all the
different names for each possible drive will have to be catered for. I
can't see why this is necessary. No software that I know of needs to
know the capacity of the drive. Even if there is and I've just thought
of a few cases, then surely the driver should supply this information.

As an example, say I change my old 5.25 disk for a nice new 2.88M 3.5.
If we use the hardware based scheme then I'll have to modify all my
software to use the new device name. Ok I hear you say, make a  link.
Well if we all link these hardware based names to something like /dev/fp
then why not just make it the standard in the first place.

If we use /dev/fp and I change my drive nothing has to change except the
major/minor device number. All software still accesses /dev/fp and the
driver takes care of the underlying hardware.

To sum up, I think device names should be based on whether there are
different drivers and not on different hardware.

-- 
  Paul Richards at Cardiff university, UK.

  [email-masked]	Internet: [email-masked]
  UUCP:     [email-masked] or ...!uunet!mcsun!ukc!cf!thor!spedpr
+++

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From: [email-masked] (Bruce Varney)
Date: Sun, 5 Apr 92 20:30:04 EST

In the unforgettable words of  Paul Richards:
->
->
->device specific names. Why can't we just have /dev/fpx where x is a
->number or letter or whatever. There's only one device driver for floppy

	YES!!!

->If we use /dev/fp and I change my drive nothing has to change except the
->major/minor device number. All software still accesses /dev/fp and the
->driver takes care of the underlying hardware.
	YES!!!

	THANK YOU
	At least I know someone out there agrees with me.
			Bruce

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From: [email-masked]
Date: Sun, 05 Apr 92 19:56:54 MST

--------

    	YES!!!

    	THANK YOU

--------
The problem with this approach is that high density and extra density        
floppies can support two or more denisties per drive.  So that these 
are accesable to the user, either

1.  The kernel must check for disk type.
2.  The user must be able to specify media density, ie with a suffix.

Unless you're willing to volunteer for floppy disk driver work,
or some one else is, the later is what we are stuck with.

AIX uses the later approach, with 
/dev/fd[n] the default, high density media, and 
/dev/fd[n] available for low density media.

---

From: [email-masked] (Bruce Varney)
Date: Sun, 5 Apr 92 21:19:17 EST

->The problem with this approach is that high density and extra density        
->floppies can support two or more denisties per drive.  So that these 
->are accesable to the user, either
->
->1.  The kernel must check for disk type.
->2.  The user must be able to specify media density, ie with a suffix.
->
->Unless you're willing to volunteer for floppy disk driver work,
->or some one else is, the later is what we are stuck with.
->
	If I had a machine to do it on, I would gladly. Anyone wanna
make a donation? ;-)

	Dos doesn't require that you specify which density your disk 
is. So it obviously isn't impossible for the OS to determine it. I am
not completely familiar with how floppies are layed out, but isn't there
something that is peculiar to each density? Even Minix has a device
(/dev/fd0 or something) that will figure out for you what density
disk is in the drive.

			Bruce