No Error Message Generated on MOV
ID Number:  Q11534

4.00
MS-DOS
buglist4.00 fixlist5.00 

Problem:

The following program assembles with no error messages, although the
second form of the MOV instruction is incorrect and will not assemble
with the segment override (this can be checked with SYMDEB): 

    other   segment
    other   ends

    test    segment
            org  100h
            ASSUME  CS:test, es:other

    START:
            mov   ax, other
            mov   es, ax

            MOV   ES:[bx], al     ; This codes the segment override,

            MOV   [ES:bx], al     ; this does not. No error reported.

    test    ends
            end   start

Response:

The correct syntax should be used at all times (the segment override
is coded outside the brackets). 

Microsoft has confirmed this to be a problem in Version 4.00. This
problem was corrected in MASM Version 5.00. 
