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Q68071: FIX: MASM Aligns on 4-Byte Boundary After Offset 8000h

Article: Q68071
Product(s): Microsoft Macro Assembler
Version(s): 5.1,5.1a
Operating System(s): 
Keyword(s): 
Last Modified: 04-FEB-2002

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

- Microsoft Macro Assembler (MASM), versions 5.1, 5.1a 
-------------------------------------------------------------------------------

SYMPTOMS
========

The module below demonstrates a problem with the Microsoft Macro Assembler
(MASM) versions 5.1 and 5.1a. If an EVEN directive is used after an offset of
8000h within a segment, the assembler will try to align the next instruction or
data element on a 4-byte boundary. In other words, more bytes for padding will
be added than are necessary to achieve even alignment.

STATUS
======

Microsoft has confirmed this to be a problem in MASM versions 5.1 and 5.1a. This
problem was corrected in MASM version 6.0.

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

The following is the assembly listing that is generated for the example below.

Assembly Listing
----------------

Code Generated   Source
--------------   ------

F8               clc
90               EVEN
F8               clc
                ORG 8000h
F8               clc
87 DB 90         EVEN
F8               clc

Sample Code
-----------

  ; Assemble options needed: none

  _TEXT SEGMENT PARA PUBLIC 'CODE'
  ASSUME CS:_TEXT
  start:
      clc
      EVEN
      clc
      ORG 8000h
      clc
      EVEN
      clc
  _TEXT ENDS

  END start

Additional query words: 5.10 5.10a buglist5.10 buglist5.10a fixlist6.00

======================================================================
Keywords          :  
Technology        : kbMASMsearch kbAudDeveloper kbMASM510 kbMASM510a
Version           : :5.1,5.1a
Solution Type     : kbfix

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

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