      -----------------------------------------------------------------
      STACKER NOTE                                         STACKER NOTE
            INSTALLING OS/2 ON A STACKER FOR WINDOWS & DOS SYSTEM
                 (Applies to Stacker 4.0 for Windows & DOS)
      STAC FAX  4525 (11-22-1994)
      -----------------------------------------------------------------
                                      
      BACKGROUND
      
      If you have setup Stacker for Windows & DOS, there are two
      situations where you may consider it possible to install OS/2.
      The first is when you have not compressed drive C. The second is
      when there is sufficient uncompressed space on physical drive C
      to accept an OS/2 installation. Stac's recommendation is that you
      avoid installing OS/2 on a system running Stacker for Windows &
      DOS. There are two problems: in either situation you will not
      have access to any compressed drives when you are booted into
      OS/2, and in the second situation the dual boot feature will not
      operate properly. If you wish to use OS/2 and compression, you
      should use Stacker for OS/2 & DOS instead. Contact Stac at (800)
      522-STAC for details on obtaining the current Stacker for OS/2 &
      DOS product.
      
      Issues with OS/2 and Stacker 4.0 for Windows & DOS
      
      If you have not compressed drive C, or have sufficient
      uncompressed space on physical drive C, OS/2 will successfully
      install on that drive. It will detect the presence of DOS on the
      system, and will automatically configure itself as "Dual Boot".
      That is, you may execute a command to cause the system to start
      into DOS if you are in OS/2, or into OS/2 if you are in DOS.
      
      When the system is started into OS/2, there will be no Stacker
      compression drivers present. Therefore, when you start OS/2, you
      will not have access to any compressed drives on your system. For
      example, if you compressed drive D, you will not see your data
      when you examine drive D. You will only see the uncompressed
      portion of the drive.
      
      If you installed OS/2 onto the uncompressed portion of the boot
      drive (physical drive C), then the dual boot feature will not
      operate properly. You will be able to dual boot from OS/2 to DOS,
      but you will not be able to dual boot back to OS/2. OS/2's
      BOOT.COM is unable to locate the true physical boot drive and
      update the boot record. The only method of enabling dual boot
      back to OS/2 is to make the physical boot drive available to
      BOOT.COM. The procedure is cumbersome, but is provided here as a
      temporary work-around until you update your system to Stacker for
      OS/2 & DOS.
      
       1.  Disable swapping of the boot drive. Type ED /I <enter>.
       2.  Locate the line that loads the STACVOL file on drive C. It
           should look something like this:
           C:\STACVOL.DSK,SW
       3.  Change the SW parameter to NS in order to disable swapping.
           The line should now look like this:
           C:\STACVOL.DSK,NS
       4.  Press CTRL-Z to save the file, then restart the system.
       5.  Change to the OS2 directory and type BOOT /OS2 <enter>. OS/2
           will start.
       6.  After you finish your OS/2 session and boot back into DOS,
           you must restore drive swapping. Change to the Stacker
           directory on drive C and type ED /I <enter>.
       7.  Again locate the line that loads the STACVOL file on drive
           C. Restore the SW parameter to the end of the line. It
           should now look like the example in step 2.
       8.  Save the file with a CTRL-Z, then restart the system for the
           swapping to take effect.
       9.  Follow this procedure each time you use the dual boot
           feature.
           
      As you can see this procedure is unwieldy, and typing mistakes
      may make your compressed drive unavailable. Stac strongly
      recommends using Stacker for OS/2 & DOS rather than Stacker for
      Windows & DOS. The recommended procedure is to uncompress your
      drive(s), then install Stacker for OS/2 & DOS. See the Stacker
      4.0 for Windows & DOS User's Guide for information on
      uncompressing Stacker drives.
      -----------------------------------------------------------------
      Copyright 1994 Stac Electronics
