Q31144: MEP Crashes OS/2 when Switching from Real-Mode Screen Group

Article: Q31144
Product(s): See article
Version(s): 1.00   | 1.00
Operating System(s): MS-DOS | OS/2
Keyword(s): ENDUSER | TAR75546 TAR76522 | mspl13_basic
Last Modified: 28-OCT-1988

When running in OS/2 protected mode, the system may crash when
switching between protected mode and real mode and using the ALT+ESC
sequence. It may take several iterations of ALT+ESC before the failure
occurs.

The system crashes when switching from the real-mode session into a
protected-mode session that is running MEP. When the system crash
occurs, the following message appears:

    TRAP 000D

    <register contents>

    The system detected an internal processing error
    at location # 3430:0590
    Exception while in kernel mode

    The system is stopped

This is not a problem in MEP; it is a problem in OS/2.

You can work around this problem by not running MEP in the original
("default") protected-mode screen group. Instead, start a second
protected-mode screen group and run MEP there. To move to the second
protected-mode screen group, do the following:

1. Press ALT+ESC from real mode to get to the original
   protected-mode screen group.

2. Press ALT+ESC again to get to the MEP screen group.

Running MEP in a second screen group prevents you from switching
directly from real mode into the MEP screen group.

Another workaround for this problem is to use the CTRL+ESC hotkey
rather than the ALT+ESC command to leave the real-mode screen group.
The CTRL+C hotkey brings you back to the program selector. Once
there, you can select the next screen group by using the mouse or
cursor keys.