From: SK0001@ACAD.DRAKE.EDU (Sal Kabalani)
Newsgroups: comp.os.vms
Subject: The Scoop on VMS ZIP and UNZIP
Date: 5 Sep 92 02:46:59 GMT
Organization: The Internet

Hello All.

Someone sent the following message to info-vax and didn't leave a return 
address, so I am posting the response to INFO-VAX.

>I am using a version of PK-ZIP/UNZIP for VAX/VMS, a public domain or
>shareware file compression program.  This is version
>4.1, I believe, and it contains a bug (?) in which all de-compressed files
>have the Stream_LF Record format.
>
>Does anyone know if there is a new version
>available (and from where?) in which this
>bug has been fixed?
>
>Many thanks!

Text file transfer between DOS and VMS machines is a vital part of our
day-to-day operation, so I have been following this topic with great interest.
Here are the results of my research:

Using the new VAX ZIP/UNZIP, in conjunction with the new PKZIP version 1.93 
Alpha, I was able to transfer files between MS-DOS and VMS successfully, and   
reproduce them accurately on the target machine.

The software I used in my tests are: ZIP V 1.9, 20-Aug-1992; UNZIP V 5.0, 
21-Aug-1992; and the ALPHA test version of PKZIP 1.93. 
 
The only problem at this point is that the version of PKZIP I used is only an 
ALPHA test version. It is NOT a production version. You will need to wait 
until PKWARE releases PKZIP 2.0. This will be around October or November of
this year. (PKWARE tech support was not able to give me exact release time.)
As a personal opinion, I think all of us who use PKZIP should pay the shareware
fee to support such an brilliant product. I also would like to salute all those
who worked hard to make portable ZIP such a great product. Thanks guys :)

The new ZIP/UNZIP uses a new method of compression called Inflate (and its
counterpart Deflate). This seems to be the preferred method of compressing text
files used by ZIP/UNZIP, and this is the reason why I needed to use the new
PKZIP for my testing. Inflate is supported ONLY in PKZIP 1.93 Alpha and PKZIP
2.0.

It is important that you do not use the ALPHA version of PKZIP as a production
version. I strongly recommend that you wait until 2.0 is released. A word
of caution: There has been a few HACKED versions of PKZIP floating around
bearing the version number 2.0. DO NOT USE THEM. They may render your data
unusable. When PKWARE does release 2.0, I recommend that you call their BBS
and download the software yourself.

I have tested these programs with small files (under 15K) and with meduim-size 
files (225K VAX->MS-DOS, 140K MS-DOS->VAX). I assume the software will produce
the same results with any-size files. (We have been using ZIP/PKZIP on files up
to 20 MEG in size with no problems).

Transferring ZIPped text files from VAX to MS-DOS, then PKUNZIPping them on DOS
will reproduce the file accurately, including <CR> <LF> characters. 
Transferring PKZIPped text files from MS-DOS to VAX, then UNZIPping them on VMS
will reproduce the file accurately in a Sequential Variable Record Size
format. As far as my needs go, this is MUCH better that the old STREAM_LF
format.
 
I am listing prameter settings to successfully exchange ZIP files between VAX 
and MS-DOS.

                                       Kermit File Type
         ----Transfer---
          From      To     ZIP Flags   MS-DOS      VAX    UNZIP Flags
         ______   ______   _________   ______     _____   ___________

         VAX      MS-DOS   -l -k -V    Binary     Fixed   None
         MS-DOS   VAX      None        Binary     Fixed   -a   

I have not tested the file transfer with Zmodem, or any other protocol, but I
think the results will be the same. Also I have not tested the transfer of
Binary file transfer. I have no need to. If anyone discoveres a problem
transferring binary files, I would appreciate it if they let us know.

Hope this helps. If anyone thinks I have arrived at the wrong test results or
conclusions, please feel free to correct me.

.-Sal A Kabalani----------+--Internet: SK0001 @ Acad.Drake.Edu----------------.
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