JP Software

                    4DOS Patch Program Documentation

                            4.01June 8, 1992


Copyright 1988 - 1992, JP Software Inc., All Rights Reserved.  Published
by JP Software Inc., P.O. Box 1470, E. Arlington, MA 02174 USA, (617)
646-3975.


This file explains briefly how the 4DOS 4.01 patch program PATCH.EXE
works and how to use it.

The patch program cannot be used by itself -- you must also have a patch
file.  The patch program is provided separately so you can download it
once, then use it with individual patch files when they are issued,
without having to download another copy of the patch program with each
patch file.

The patch program converts one or more old 4DOS or 4OS2 files to the
most recent version.  It is part of the .RTPatch software update package
from PocketSoft Inc. (see below).  JP Software uses .RTPatch to generate
"patch" files which contain the differences between the old and new
versions of one or more 4DOS or 4OS2 files.  You then apply these
patches to your copy of 4DOS or 4OS2 to update it to the latest version. 
The patches are usually much smaller than the new file, so this approach
saves download time.

A typical patch will include a patch file with the extension .RTP, and a
documentation file with the extension .DOC.  The documentation file with
each patch explains the details for that patch, but in general a patch
is applied in three steps:

       (1) Collect the files to be patched and the patch (.RTP) file
       into a single directory.  The patch will not work unless all
       files are in the same directory.  The PATCH.EXE program should be
       in that directory as well, or located in a directory on your
       PATH.

       (2) Change to the new directory.

       (3) Enter the command:

                 PATCH . [patchname]

       where [patchname] is the name of the .RTP file (without the
       extension or the square brackets).  Note that a "." is required
       between the PATCH command and [patchname].


There are a few additional things you should be aware of when running
PATCH:

   **  You can only patch the original file for which the patch was
       generated.  If any of the files to be patched has been modified
       in any way since you received it from JP Software, or is not the
       exact version for which the patch was created, then that file
       will not be patched.  For example, if you edit a documentation
       file or an icon, or compress an executable file with PKLITE or
       DIET, then PATCH will not update the file.  This is a safety
       feature which prevents PATCH from modifying the wrong version of
       a file.  The exception is 4DOS and 4OS2 BRANDing:  our patch
       files are constructed to handle the changes created by the BRAND
       program, and to automatically transfer the brand from your old
       4DOS or 4OS2 executable file to the new file.

   **  PATCH will ignore missing files.  If the patch you are installing
       is for multiple files and only some files are present, only those
       files will be updated.  You can copy additional files later and
       rerun the PATCH command to update them; this will cause some
       harmless messages when PATCH finds some of the files have already
       been patched.

   **  PATCH can be run from DOS, from an OS/2 DOS session, or from an
       OS/2 protected-mode session under 4OS2.EXE or CMD.EXE.  Do not
       use PATCH to update executable files like 4OS2.EXE from an OS/2
       protected-mode session while the program to be updated is
       running.  OS/2 does not allow executable files to be modified
       while they are in use, so PATCH will not be able to update the
       file.  Instead, end the program before applying the patch.  If
       you prefer you can copy the file to another directory, apply the
       patch there, and then either end the program and copy the
       modified file back to the original location, or reconfigure your
       system to use the modified file in the new directory.


[PATCH.EXE is a copyrighted program, distributed under license to JP
Software.  For more information on the complete .RTPatch software update
package contact PocketSoft, Inc., P.O. Box 821409, Houston, TX 77282,
USA, phone 713-460-5600, fax 713-460-2651.  .RTPatch is a trademark of
PocketSoft Inc.]