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Q60267: FIX: Error A2057 With DOS.INC, .386, and MASM 5.1 or 5.1a

Article: Q60267
Product(s): Microsoft Macro Assembler
Version(s): 5.1,5.1a
Operating System(s): 
Keyword(s): 
Last Modified: 06-MAY-2001

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

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

SYMPTOMS
========

The Microsoft Macro Assembler (MASM) versions 5.1 and 5.1a generate the
following error when the DOS.INC include file is used in conjunction with the
.386 or .386P directive.

  error A2057: Illegal size of operand

RESOLUTION
==========

No errors occur if the USE16 use type is used in the SEGMENT statement. This
generates a 16-bit offset for the DOS.INC macros, whereas a 32-bit offset is
generated without the USE16, and produces an error.

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 DOS.INC files are provided on disk 2 of the MASM version 5.1 disks, for
simplified use of the DOS calls.

The following assembly listing produces the error mentioned above:

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

  ; Assemble options needed: none

  .386
  INCLUDE dos.inc

  _datas  SEGMENT word 'data'     ; add USE16 for a work-around
  msg     DB      'Hi,there'
  msglen  EQU     $-msg
  _datas  ENDS

          ASSUME  cs:_codes
  _codes  SEGMENT word 'code'
  start:  MOV     ax, _datas
          MOV     ds, ax          ; set ds to point to message

          @write  msg, msglen     ; error A2057 occurs here
          @exit

  _codes  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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