Dear SCO Customer,

The enclosed Support Level Supplement (SLS) PTF3191, the 4GB User Space
Supplement, allows the kernel to access memory above the 2 gigabyte range.
SLS PTF3191 also installs a modified async driver that permits one process
to lock-down  multiple segments of physical memory for asychronous i/o. SLS
PTF3191 also allows the system administrator greater flexibility in defining 
the amount of physical memory allocated as user space.


Software Notes and Recommendations
----------------------------------

SLS PTF3191 is targeted for SCO UnixWare 2.1.1 or 2.1.2 running on
systems that can accommodate physical memory in excess of 2 gigabytes. 
Although PTF3191 will install on systems with less than 2GB, there is 
nothing to be gained from doing so.

Installation Instructions
-------------------------

1. Become root and create a new directory by typing the following:

     $ su
             (Password: <type your root password>)
     # mkdir /tmp/pkg
     # chmod 700 /tmp/pkg
     # cd /tmp/pkg

2. Download the ptf3191.Z and the ptf3191.txt files to the newly
   created /tmp/pkg directory on your machine.

3. Read the Release Notes contained in the ptf3191.txt file.

4. Add the package to your system using the following commands:

     # zcat /tmp/pkg/ptf3191.Z | pkgadd -d -

   Alternately, you can uncompress the PTF and install it as follows:

     # uncompress ptf3191.Z
     # pkgadd -d /tmp/pkg/ptf3191

5. Reboot the system after installing this PTF.


Removal Instructions
---------------------

1. Become root and remove the package by typing these commands:

     $ su
             (Password: <type your root password>)
     # pkgrm ptf3191

2. Reboot the system after removing this PTF.


If you have questions regarding this SLS, or the product on which it is
installed, please contact your software supplier.

We appreciate your business.

SCO Support Services