OSHTHANG - INTERMITTENT LOCKUPS RUNNING OS/2 2.X
01/29/96

=======================================================================
                Intermittent Lockups Running OS/2 2.x
=======================================================================

Please Read Entire Document for Full Explanation of Procedures
--------------------------------------------------------------

DESCRIPTION

This document provides information to help you determine the cause of 
intermittent lockups (or hangs).

RESOLUTION

Note: Make sure you have a backup of any file you intend to change.

* If the system locks up only when running a DOS or Windows program,
  the problem is probably with an application:

  - If you are running an application from an icon, does the system
    lock up if you run it from the command prompt? If so, the icon
    might be corrupt. Delete it and re-migrate the application or
    create it from the program template.

  - Does pressing Ctrl+Esc eliminate the lockup? If so, it is an
    application problem; contact DOS or Windows support. If not, can
    you restart the system by pressing Ctrl+Alt+Del, or do you have to
    turn the system off?
       
    Do certain applications lock up or do all of them lock up? If the
    problem is specific to certain applications, try changing some of
    the following settings:

       DPMI_MEMORY_LIMIT to 64
       DOS_RMSIZE        to 624
       HW_ROM_TO_RAM     to ON
       HW_TIMER          to ON (games or timing-sensitive applications)
       IDLE_SECONDS      to 60
       IDLE_SENSITIVITY  to 100
       EMS_MEMORY_LIMIT  (increase or decrease depending on application
                          needs)
       XMS_MEMORY_LIMIT  (increase or decrease depending on application
                           needs)
       INT_DURING_IO     to ON (Multimedia applications and other DOS
                                applications)

    Note: These are general settings and might affect each application
          differently. If the above information does not solve the
          problem, contact OS/2 Support and ask for the DOS or Windows
          application group.

* If the entire system is locking up randomly:

  1. Run diagnostic tests to see if there is a hardware problem. The
     Diagnostics diskette contains the hardware-checking program.

     Note: For a Micro Channel system, get the diskette from the
           hardware vendor or your Marketing Representative.

           For an Industry Standard Architecture (ISA) system, (also
           called AT-bus system) refer to the system's hardware manual.

  2. Edit the CONFIG.SYS file and add the following as the second line
     of the file:

        SET SHELLEXCEPTIONHANDLER=OFF 

     This might produce an error message to the Desktop when the system
     locks up.

  3. Check interrupt-request (IRQ) assignments and communication (COM)
     ports. The AT-bus cannot share IRQs, addressing, or direct memory
     access (DMA). Also, it cannot skip COM port settings.

  When OS/2 starts, it opens all applications that were previously
  running in OS/2. If the Desktop is displayed when the system starts,
  and a previously opened application causes the system to lock up, do
  the following:

  1. Edit the CONFIG.SYS file and add SET RESTARTOBJECTS=NO. When you
     start the system, the applications that were running under OS/2
     when the system was shut down will not restart.

     * If you have DOS on the system, and OS/2 is using the FAT file
       system, use a DOS startable diskette, or start DOS; then edit
       the CONFIG.SYS file and add the above statement.

     * If you do not have DOS on the system:

       a. Start the system with the Installation Diskette.
     
       b. When prompted, remove the Installation Diskette and insert
          Diskette 1.

       c. At the Welcome screen, press Esc to get the A: prompt.

       d. Type x: and press Enter (x is the drive where OS/2 is
          installed).

       e. Type COPY CONFIG.SYS CONFIG.BAD and press Enter to back up
          the CONFIG.SYS file. If a CONFIG.BAD file already exists, use
          a different extension.

       f. Type ECHO SET RESTARTOBJECTS=NO >> CONFIG.SYS and press Enter
          to add the line to the CONFIG.SYS file.

  2. After the system loads the CONFIG.SYS file, you also can bring up
     the Desktop without any applications opening by pressing
     Ctrl+Shift+F1. If you hear a beeping sound, release the keys for a
     moment, and then press them again.
            
  This procedure does not work as well as adding the statement,
  SET RESTARTOBJECTS=NO, to the CONFIG.SYS file.

______________________________________________________________________
IBM disclaims all warranties, whether express or implied, including 
without limitation, warranties of fitness and merchantability with 
respect to the information in this document. By furnishing this 
document, IBM grants no licenses to any related patents or copyrights.  
Copyright (c) 1994, 1996 IBM Corporation. Any trademarks and product 
or brand names referenced in this document are the property of their 
respective owners. Consult your product manuals for complete trademark 
information.