Message-ID: <67BAFB085CD7D21190B80090273F74A45B7D47@emwatent02.meters.com.au>
From: "Da Silva, Joe" <Joe DOT daSilva AT emailmetering DOT com>
To: "'opendos AT delorie DOT com'" <opendos AT delorie DOT com>
Subject: RE: LZW (was PKZIP 2.50 for DOS)
Date: Mon, 13 Nov 2000 12:26:03 +1100
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Reply-To: opendos AT delorie DOT com

Hmmm ...

I'm no expert on this, so perhaps some subtlety has "escaped me".
However, as far as I can determine, the PKZIP compression method
#1 (shrinking), uses LZW (presumably with the consent of Unisys) ...

Regarding LZW, I wonder when this infamous patent will expire???

Joe.

> -----Original Message-----
> From:	Glenn McCorkle [SMTP:glennmcc AT cisnet DOT com]
> Sent:	Saturday, 11 November 2000 11:55
> To:	opendos AT delorie DOT com
> Subject:	Re: PKZIP 2.50 for DOS
> 
>  Well.....
> PKzip and PKunzip don't support the LZW format either.
> That's because LZW is not a compression format for archiving utilities.
> It's the compression format for GIF graphics files.
> And yes, Unisys/Compuserve owns the rights to GIF/LZW
> 
> Not many people realize that the LZW algorithm can also used for TIFF and
> JPG
> 
> For an in-depth explanation.....
> http://www.whatis.com/WhatIs_Definition_Page/0,4152,214337,00.html
> 
> Oh, and the term is "floppy disk spanning". ;-)
> 
> 
> On Fri, 10 Nov 2000 16:30:52 +1100, Da Silva, Joe wrote:
> 
> > Well, yes and no.
> 
> > Yes, because it's free and (IIRC) open-source.
> 
> > No, because it doesn't support that compression
> > type that Unisys has a patent on (LZW?), so I
> > guess it won't decompress a file using this.
> 
> > Also, no because it *still* (last time I checked !!!)
> > doesn't support floppy disk spawning (have I got
> > that terminology right ... ?).
> 
> > Joe.
> 
> >> -----Original Message-----
> >> From: Florian Xaver [SMTP:dos DOT fire AT aon DOT at]
> >> Sent: Saturday, 11 November 2000 4:53
> >> To:   opendos AT delorie DOT com
> >> Subject: Re:       PKZIP 2.50 for DOS
> 
> >> Another, better solution is to use INFOZIP. You can find it at
> >> www.opus.co.tt/dave/.
> 
> >  ----- snip -----
> 
> --
>  Glenn
> (your friendly neighborhood compu-nerd)
>  http://www.delorie.com/listserv/mime/
>   http://freedos-32.sourceforge.net/