[ros-dev] Patent on FAT

James Tabor jimtabor at adsl-64-217-116-74.dsl.hstntx.swbell.net
Fri Jan 13 20:17:57 CET 2006

Hi all,
I think this is important to share to the discussion. From one of the developers
with FreeDOS, Eric Auer.


-------- Original Message --------
Subject: [Freedos-user] re: FAT and other file systems
Date: Fri, 13 Jan 2006 17:16:34 +0100 (MET)
From: Eric Auer <eric at coli.uni-sb.de>
Reply-To: freedos-user at lists.sourceforge.net
To: freedos-user at lists.sourceforge.net

Hi James,
> > And I think it is not more difficult to write HFS or FFS in the kernel
> > of FreeDOS than ReiserFS or XFS or all the other candidates.

I would like to comment this as follows: The Linux kernel modules for
ext3+jbd take 131+59k of memory. Reiserfs takes 243k (243*1000 bytes,
too lazy to convert to units of 1024 bytes). On the other hand, FAT
core takes 38k and you use it with either MSDOS (8k) or VFAT (13k)
implementations. Only the VFAT (long file name enabled) module of
Linux is affected by the 3 MS patents mentioned on the MS homepage.

> There is no way around this, unless someone will write a disclaimer, "Before
> you install FreeDos, do you want to enable Fat32 Patented Features"?

Microsoft WANTS you to believe that they patented FAT32.
Actually they patented their clever but twisted way to store
short and long filenames in the same directory, in a way which
allows LFN-unaware operating systems to use the drive without
getting confused by the LFN data and usually also without
damaging the LFN data either. But you already point that out yourself:

> We are
> facing the same issue with Ros. When I use FreeDos, I use the basic 8.3
> file system, so I don't see that as a major problem. The point here is the
> patent is about LFN, basic 8.3 is not effected.

So the disclaimer would only be displayed when you install the DOSLFN
package: "Install DOSLFN, which might have patent issues?". FreeDOS as
a DOS operating system itself is not affected by that problem. Plus
MS does have a disclaimer about their licensing, too:

which is more than 5 years old by now...
allows you to be compatible to all their FAT (including LFN) stuff
for the purpose of booting, OS installation, diagnosis, firmware,
similar things. They also tell that making/installing operating
systems may use all aspects of FAT. You could see this in a pessimist
way (you are allowed to develop and compile your OS on a LFN enabled
host system) or in a more optimistic way (your operating system
itself is allowed to use LFN because it simply is an operating system).

MS is targetting two groups at the moment: Vendors of USB sticks who
preinstall files on their sticks, and vendors of cams and mp3 players
and similar devices. FreeDOS is neither of those. But I did notice
that my hardware mp3 player does not support LFN. It only shows the
id3 text, if available, as "long song name", and is limited to
showing the SHORT file name as song name otherwise. Looks like
the vendor of the player did not want to pay MS for each device.

Digicams have similar issues - they usually generate filenames
like dsc0815 dot jpg and store all extra "title/name" information
inside the file (jpeg comment, EXIF data...?).


PS: I assume that you mean ReactOS, the free open WinNT clone,
when you mention Ros. ReactOS without LFN would not be the same...

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