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    AST RESEARCH, INC.           TECHNICAL BULLETIN # 0993              10-5-94

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                                  EMM386 EXCEPTION ERRORS

    NOTE:           This information pertains to Microsoft MS-DOS operating system
                    versions 4.x, 5.0, and 6.0 and Windows 3.x.

    PROBLEM:        If you install the EMM386.EXE device driver included with
                    MS-DOS and Windows 3.x, you may get an exception error such as:

                         EMM386 Exception error #13 @ xxx:xxxxxxxx CODE xxxx
                         PRESS ENTER TO REBOOT.

                    The following list contains Intel 80386 protected mode
                    exception errors.

                         0       Divide error
                         1       Debugger interrupt
                         2       Nonmaskable interrupt
                         3       Breakpoint
                         4       Overflow interrupt
                         5       Array boundary violation
                         6       Invalid opcode
                         7       Coprocessor not available
                         8       Double fault
                         9       Coprocessor segment overload
                        10       Invalid task state segment
                        11       Segment not present
                        12       Stack exception
                        13       General protection violation
                        14       Page fault
                        16       Coprocessor error

    CAUSE:          These errors mean that EMM386 is reporting an error detected
                    by the CPU in virtual mode.

    SYSTEMS
    AFFECTED:       Any computer system using the EMM386.EXE device driver.

    SOLUTION:       Remove EMM386 to determine if problems still occur without it.
                    If problems still occur, correct them and reinstall EMM386.

                    Re-install MS-Windows.  You do not need to delete the
                    existing version of Windows or DOS.