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

The information in this article applies to:

• Microsoft Macro Assembler for MS-DOS, version 6.0
• Microsoft Macro Assembler for OS/2, version 6.0

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)

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