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Q79829: FIX: /Zm and $-Constant Produces A2075 in MASM 6.0

Article: Q79829
Product(s): Microsoft Macro Assembler
Version(s): 6.0
Operating System(s): 
Keyword(s): 
Last Modified: 04-MAY-2001

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

- Microsoft Macro Assembler (MASM), version 6.0 
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SYMPTOMS
========

In the Microsoft Macro Assembler (MASM) version 6.0, the following error message
may be produced

  A2075: jump destination too far : by xxxxx byte(s)

when using the /Zm option, the MASM driver with MASM 6.0, or OPTION M510. When
MASM 5.1 compatibility is not used or MASM 5.1 is used, the code assembles
correctly.

CAUSE
=====

This behavior is caused by using the current address operator, $, minus a
constant (for example, jmp $-5), and the MASM driver with MASM 6.0, OPTION M510,
or the /Zm switch when assembling.

RESOLUTION
==========

Use a label instead of the current address operator or assemble without the MASM
5.1 switch.

STATUS
======

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

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

The /Zm switch is the MASM 5.1 compatibility switch in MASM 6.0. The MASM driver
calls ML with the /Zm option in MASM 6.0. OPTION M510 is a directive that
specifies MASM 5.1 compatibility.

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

  ; Assembly options need: /Zm

  DOSSEG
  .MODEL small
  .STACK 4096
  .DATA
  .CODE
  start:  mov     al,5h
  here:   dec     al
          jnz     $-2             ; This line causes the A2075 error.
          ;jnz    here            ; Uncomment this line and comment out
          mov     ax,4c00h        ; jnz $-2 to get the code to assemble
          int     21h             ; correctly.
  END     start

Additional query words: 6.00 5.10 buglist6.00 fixlist6.00a

======================================================================
Keywords          :  
Technology        : kbMASMsearch kbAudDeveloper kbMASM600
Version           : :6.0
Solution Type     : kbfix

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

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