For preserving MPE filecodes, I am working with the two versions (3K and
PC) of LZW, courtesy of Adager on the 3K and from the Telamon web site
for the PC (ftp://ftp.telamon.com/dist/lzwpc.exe); I recently posted to
see if others had benchmarked the benefits. LZW is not for the timid;
proceed at your own risk ;-) . Actually, I am relatively happy with it,
as it takes less than half as long to compress / upload /decompress as
it takes me to just upload, but LZW's behavior can range from the obtuse
to the infuriating. Functions that seem like they reasonably should work
frequently respond differently, or by simply redisplaying the help text.
If I weren't developing this as a batch, I might not bother, although
now that I am getting used to it, I have started using it ad hoc. I
choose minimum compression (-M 9), which is quite good, because it runs
more slowly compressing files on the LAN side, but what takes minutes
there takes seconds on the 3K. I'll likely benchmark different value for
this settings in the batch process later as well.

Here are my notes so far, for what it's worth. What I haven't explained
was clear enough to me from the help that I frequently displayed: -F
archive name -S file to store -T record length in bytes (LAN only).
Compressing with LZW on the HP, for the LAN:
I have to already be in my source group, or my MPE group becomes my DOS
extension.
LZW.LIBRARY.REGO "-F X016001.LZW -S X016001 -M 9"
On the LAN, for the HP:
LZW -F ..\LZW\X016001.LZW -S X016001.IN -T 1234 -M 9

Decompressing with LZW on the HP:
LZW.LIBRARY.REGO "-F X016001.LZW -R X016001"
On the LAN:
I start in my target directory; if not, the file will be written to the
current directory, overwriting any existing version of the file.
LZW -F ..\LZW\X016001.LZW -R X016001

Note, that when using Reflection File Transfer to download the file, it
is necessary to 'rename' the LZW to have an extension, or to omit the
.LZW extension deliberately when decompressing. When uploading, I use
record length 512B, fixed binary, and specify filecode 665 (or LZW will
complain of an Invalid archive file code); making these mistakes cost
much of the gain achieved by compressing. Using ftp, this can be
accomplished using buildparms, supplying a target file name, and
REC=-512,,F,BINARY;CODE=665;DISC=99999. Best wishes.

> ----------
> From:         Mark Bixby[SMTP:[log in to unmask]]
> Sent:         Thursday, March 05, 1998 5:54 PM
> To:   [log in to unmask]
> Subject:      Re: [HP3000-L] Compression utility
>
        <snip>
> > Patrick, who isn't sure but suspects this is all easier than he
> thinks.
>
> You're right on this one.  :-)
>
> But just remember that MPE zip/unzip DOES NOT preserve MPE file
> attributes
> like filecode.  Also, it will create bytestream files when unzipping.
<snip>