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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.