DOCUMENT:Q92868  26-JUN-2001  [utilities]
TITLE   :FIX: CodeView 4.0 and 4.01 Cannot Debug COM Files
PRODUCT :Microsoft Programming Utilities
PROD/VER::
OPER/SYS:
KEYWORDS:kb16bitonly

======================================================================
-------------------------------------------------------------------------------
The information in this article applies to:

 - Microsoft CodeView for MS-DOS 
-------------------------------------------------------------------------------

SYMPTOMS
========

An attempt to debug a COM file with Microsoft CodeView fails.

CAUSE
=====

Due to an incompatibility between CodeView versions 4.0 and 4.01 and Microsoft
LINK versions 5.3 and 5.31.009, the symbol offsets stored in the DBG file differ
by 0x100 from the offsets stored in the symbol table in the COM executable file.

RESOLUTION
==========

Build the application using the small memory model during the development phase.
Once the application has been debugged, switch to the tiny memory model for the
final build.

STATUS
======

Microsoft has confirmed this to be a problem in CodeView versions 4.0 and 4.01
for MS-DOS. This problem was corrected in CodeView version 4.1 for MS-DOS.

MORE INFORMATION
================

COM files are built using the tiny memory model. A COM file combines its logical
code and data segments into one physical segment. Because the debugging
information that CodeView requires cannot fit in the physical segment, is it is
placed into a separate DBG file.

Additional query words: 4.00

======================================================================
Keywords          : kb16bitonly 
Technology        : kbAudDeveloper kbCodeView kbZNotKeyword3
Version           : :
Solution Type     : kbfix

=============================================================================

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS
PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND.  MICROSOFT DISCLAIMS
ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES
OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.  IN NO
EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR
ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL,
CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF
MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGES.  SOME STATES DO NOT ALLOW THE EXCLUSION
OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES
SO THE FOREGOING LIMITATION MAY NOT APPLY.

Copyright Microsoft Corporation 2001.