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   Pmswap.exe - a context switcher for Pegasus Mail,  
   (c) 1991, David Harris, Dunedin, New Zealand.      
                                                      


PLEASE READ THIS FILE VERY CAREFULLY!

Pmswap allows you to use Pegasus Mail almost as if it were a TSR: it
swaps out part of the foreground application, then loads Pegasus Mail
into the freed memory. When you leave Pegasus Mail, the original
application is restored, and you pick up where you left off.

Pmswap will swap the foreground application to EMS memory, XMS
memory, or to disk, and occupies from 1.5KB to 6KB of RAM depending
on the swapping mechanism used.

Like Pegasus Mail, Pmswap is free, copyrighted software. It is not
Shareware, nor is it in the Public domain. You may use and distribute
Pmswap freely and without restriction provided it is not sold, or
modified in any way.

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  *** NOTE *** PMSWAP will NOT work if you are using the Novell XMSNET 
  shell in your system.                                                
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Installing Pmswap

To install Pmswap, copy the file Pmswap.exe to your fileserver, or
local hard disk. Since Pmswap may be freely distributed, you can
install it on as many machines as you wish. Of course, Pegasus Mail
should already be installed on your server (or else there's very
little point in having Pmswap!).


Running Pmswap

Running Pmswap is a little trickier: you will probably want to create
a batch file to do this, since there are several parameters which
must be passed on the command line. Normally, you will invoke Pmswap
as follows:

   pmswap /ttemporary_dir /ppmail_dir

Both the /t and /p switches MUST be supplied on the command line.
If you are using QEMM-386 by Quarterdeck systems, you CAN load Pmswap
into high memory.

/t is used to indicate a directory in which Pmswap can create
temporary files if necessary. This directory should preferably be on
a local hard disk, but can be on a network path provided you have
full rights and at least 360KB available disk in that path. Do NOT
use a path to a floppy disk! This can have disastrous results. /t CAN
point to a RAM disk, which will result in huge performance gains.
The RAM disk must have at least 360KB available at all times.

/p is used to tell Pmswap where to find Pegasus Mail: provide a path
to the directory which contains Pmail.exe, but do not include
Pmail.exe itself in the path.

Note that both the /p and /t switches require fully-qualified paths
(that is, paths including a drive letter, starting at the root
directory and working down to the target directory). Both switches
also must NOT have spaces between the switch letter and the path.

Confused? Perhaps an example will help; say you store Pmail.exe in a
directory called \public\utils, which is always accessible from the
Y: drive, and you have a local drive with a directory called \scratch
where you create temporary files: you will invoke Pmswap as follows:

      pmswap /tc:\scratch /py:\public\utils


Other switches:

When loading Pmswap, there are two other switches you can use, to
control the sort of memory Pmswap will use.

   /E   - tells Pmswap NOT to use EMS memory if present.
   /X   - tells Pmswap NOT to use XMS memory if present.

By default, Pmswap will use XMS if it can find it, then EMS if it can
find it, or lastly, it will swap to disk. Note that you MUST provide
the /t and /p switches even if you have either EMS or XMS.


Invoking Pmswap

After you have loaded Pmswap, you can tell it to load Pegasus Mail
for you at any time by pressing <Alt-.> (Hold down the Left Alt key
and press the full-stop character). Pegasus Mail always starts as if
freshly loaded, on the main menu. When you quit from Pegasus Mail
(either by selecting "Quit" from the main menu, or by pressing
<Alt-F10>) you will be returned to the foreground application.


Gotchas!

Well, there always have to be a few problems! Here are some things
you should watch for when using Pmswap.

*  Don't switch to Pmail when the foreground application is a
connection-oriented program like or Procomm Plus: the result
will almost certainly hang your computer. I have tested PMSWAP with
NCSA Telnet, and it appears to work OK.

*  Pmswap will NOT pop up over Microsoft Windows in any mode. Run
Pegasus Mail in a DOS session from Windows instead.

*  Pmswap will probably not work well over programs which run in
Graphics modes.

*  Do NOT switch to Pmail when the foreground application is Pmail!
Although this won't crash the machine, it can have surprising and
unpredictable effects.

*  You will probably not be able to use an external editor from a
TSR-loaded version of Pmail (unless it is quite small).

*  If absolutely nothing happens when you press <Alt-.>, check that
the directories you gave on the command line are still valid - in
particular, make sure that you haven't deleted the drive mapping to
Pmail.exe.

*  ALWAYS use the /E switch with Pmswap (that is, disable the use of
Expanded memory) if you are using Novell's EMSNETx shell. Pmswap
and the shell do not agree if they both attempt to use the same type
of memory.


About Pmswap

Pmswap is contructed from a TSR toolkit sold by Microsystems Software
Inc, called CodeRunneR. This set of libraries for Turbo-C and MSC is
one of the slickest and most impressive I have seen, and provides
everything you could possibly need to build almost any type of TSR,
including BCD math, Multiple hot keys, task scheduling, full DOS
access from TSRs, and incredibly small TSR size. CodeRunneR costs
from US$195 to US$495 depending on the accessory kits you buy. The
actual process of building Pmswap using CodeRunneR only took a few
hours (mostly spent reading the documentation).

     Microsystems Software Inc,
     600 Worcester Road,
     Framingham, MA 01701.
     Ph: (508) 626-8511, Fax: (508) 626-8515.


Pmswap is NOT Public Domain software, nor is it Shareware: like
Pegasus Mail, it is a fully-copyrighted program which the author
chooses to give away. All rights to Pmswap are reserved by the
author. Pmswap may not be sold, either on its own, or as part of any
other package.


Contacting the author:

The author can be reached on the internet as david@otago.ac.nz. To
mail from CompuServe, send to internet:david@otago.ac.nz. On BIX, I
can be reached as dave_h.


Disclaimer

Pmswap has been tested on as many machines as I have been able to
find, under as many situations as possible. Despite this, and because
of both the program's nature, and its free distribution, no warranty
of fitness for any purpose is provided, and the author accepts no
liability for any disasters resulting from its use. By using Pmswap,
you accept this disclaimer in full.


Enjoy!

-- David Harris --
PC Consultant, Computing Services Centre, 
University of Otago, Dunedin, New Zealand

Note: Pmswap, Pegasus Mail and associated programs are not products
of, nor are endorsed by the University of Otago, although the author
gratefully acknowledges the support the University has given.

