Microsoft Macro Assembler Package
                 Version 5.00

    Text files on the Macro Assembler disks are tabbed to save
    disk space. If your printer does not automatically handle
    tabs during printing, you must use a print program that
    expands tabs. For example, use the DOS PRINT program to print
    this and other document or source files on the disk.

  Note to DOS 3.0 Users

    Because of an incompatibility between DOS 3.0 and the batch
    file enhancer on this disk, you cannot run the setup batch
    files under DOS 3.0. Instead, follow the setup instructions in
    Chapter 1 of the Programmer's Guide. You can run the CodeView
    demo on Disk 2. Type DEMO to run DEMO.BAT.

  ==( MASM.EXE )==

  New Feature

    The /LA option has been added to specify a complete listing
    of all symbols, macros, and false conditionals. It is
    equivalent to using the .LIST, .LFCOND, .LALL, and .CREF
    directives throughout the source file. The option overrides
    any conflicting directives in the source file.


    The PTR operator can be used to specify the size of a
    register indirect operand for a CALL or JMP instruction.
    However, the size cannot be specified with NEAR or FAR. Use
    WORD or DWORD instead. (In 80386 32-bit segments, use DWORD
    or FWORD.) Examples are shown below:

      ; 8086, 80826, or 80386 16-bit mode

      jmp  WORD PTR [bx]        ; Legal near jump
      call NEAR PTR [bx]        ; Illegal near call
      call DWORD PTR [bx]       ; Legal far call
      jmp  FAR PTR [bx]     ; Illegal far jump

      ; 80386 32-bit mode only

      jmp  DWORD PTR [bx]       ; Legal near jump
      call NEAR PTR [bx]        ; Illegal near call
      call FWORD PTR [bx]       ; Legal far call
      jmp  FAR PTR [bx]     ; Illegal far jump

    This limitation only applies to register indirect operands.
    NEAR or FAR can be applied to operands associated with
    labels. Examples are shown below:

      jmp  NEAR PTR pointer[bx] ; Legal
      call FAR PTR location     ; Legal

    When evaluating expressions, MASM does 16-bit arithmetic except
    when the 80386 processor is enabled. If the .386 or .386P
    directive has been given, MASM does 32-bit arithmetic. This
    behavior is consistent with earlier versions of MASM, which
    always did 16-bit arithmetic. The notes in Sections 9.2.1 and of the Programmer's Guide are incorrect. They should say
    that MASM always does 16-bit arithmetic.


    The description of declaring external symbols in Section 8.2
    is incomplete and the example is incorrect. You cannot
    access the segment of an external far data variable with the
    @FARDATA equate. Instead you must use the SEG operator as
    shown below:

         EXTRN     fvar:WORD       ; FAR variable in far data
      start: ASSUME    es:SEG fvar     ; Tell the assembler
         mov       ax,SEG fvar     ; Tell the processor
         mov       es,ax

    This is the same limitation described for communal variables
    in Section 8.4. The reason is that under the DOS segment
    conventions, multiple far data segments share the same name
    (FAR_DATA) and have private combine type. Segments with the
    same name can only be distinguished indirectly using the SEG


    The .286P and .386P processor directives enable instructions
    that are normally used in systems programming. However,
    some of these instructions do not necessarily require that
    the processor be in privileged or protected mode.


    Public absolute symbols must be declared during pass 1. This
    means that aliases for absolute symbols or other forward
    references to them will cause errors. For example, the
    following code generates an error:

         PUBLIC lines
      lines  EQU    rows
      rows   EQU    25

    This behavior is different than in previous versions of MASM
    and contrary to the note in Section 8.1.
  Behavior Change

    Some errors and questionable practices that were ignored by
    earlier versions are now flagged as errors. As a result,
    existing source code may produce errors or warnings.
    The following are examples:

      - Labels defined only during pass 1 will cause errors if
        used in expressions.
      - A CS assume that changes from pass 1 to pass 2 causes
        an error.
      - Constants are now checked for type overflow.
      - Reserved words used as labels produce warnings.
      - The OFFSET operator used with a constant causes an error.

  ==( CREF.EXE )==

  New Feature

    Cross-reference listing files created with CREF now have an
    additional symbol. A line number followed by + indicates
    that a symbol is modified at the given line. For example:

      TST . . . . . . . . . . . . . .  134#   237    544+

    The symbol TST is defined at line 134, used at line 237, and
    modified at line 544.

  ==( MASM.EXE and LINK.EXE )==


    The description of STACK combine type in Section
    does not explain how multiple initialized stack segments are
    combined. The total size of the stack is the total size of
    all stack definitions. LINK puts initialized data for each
    defined stack segment at the end of the stack. Data initialized
    in the last segment linked overrides data initialized in
    previoussegments. This behavior is usually not relevant, since
    most programs only define one stack of uninitialized data.
    Stack data cannot be initialized with simplified segment
  ==( CodeView Debugger )==

  New Feature

    The /R option has been added to enable the CodeView debugger
    to use the debug registers (DR0, DR1, DR2, and DR3) of the
    80386 processor. The option is ignored if you do not have an
    80386 processor.

    The display does not change to indicate that the debug
    registers are in use, but debugger operations with
    tracepoint or trace memory statements (but not with
    watchpoint statements) will be much faster. Any of the
    following conditions will prevent the debugger from using
    debug registers:

      1) /E is used.
      2) More than four tracepoints are set.
      3) A tracepoint watches more than four bytes of memory.
      4) A watchpoint is set.


    The Pascal expression evaluator described in the CodeView
    and Utilities manual is not implemented in this version of
    the CodeView debugger. It will be implemented in the
    debugger supplied with the next version of Pascal, which
    will also produce executable files with CodeView symbolic
    information. Current versions of Pascal do not work with the
    CodeView debugger.


    Section 4.2, "FORTRAN Expressions," of the CodeView and
    Utilities manual should mention that FORTRAN relational
    operators do not work with string variables or constants.


    Some versions of the GENOA EGA short card are incompatible
    with CodeView when used with a mouse. You can work around this
    problem by turning off the mouse with /M.
  ==( LINK.EXE )==

  New Feature

    The following new LINK message warns about a practice that is
    legal in real mode, but illegal in protected mode:

      warning L4003: intersegment self-relative fixup at <position>

    In assembly-language, the warning only occurs if the DOSSEG
    directive or /DOSSEG linker option is used. It indicates a
    16-bit jump to an address in another segment. For example,
    the following code produces the error:

          EXTRN    doit:NEAR
          jmp      _TEXT2:doit
      _TEXT   ENDS

          PUBLIC   doit
      doit    PROC     NEAR
      doit    ENDP
      _TEXT2  ENDS

    The warning usually indicates a fatal error in high-level-
    language programs. It can occur when the /NT option is used
    to compile a small-model C program.

  ==( Mixed-Languages Programming Guide )==


    Naming convention rules on page 10 are incomplete. If you
    combine BASIC with other high-level languages, avoid using
    symbolic names longer than eight characters. Pascal and C
    will recognize only the first eight characters, whereas
    BASIC will recognize more than eight characters.


    The example programs for BASIC in Chapter 6 will not work
    with QuickBASIC Versions 2.0 or 3.0. They will work if you
    rewrite the function as a subprogram, and omit the DECLARE
    statement. Functions and DECLARE statements will be supported
    in future versions of Microsoft BASIC compilers.
  ==( Macro Files )==

  New Feature

    Macro files have been added to the Macro Assembler package.
    The following files are provided:

          MIXED.INC       For defining assembler procedures
                  that can be called from high-level

          MIXED.DOC       Documentation for the macros in

          DOS.INC         For calling common DOS interrupts

          BIOS.INC        For calling common BIOS interrupts
                  used on IBM and IBM-compatible computers

          MACRO.DOC       Description, syntax, and reference
                  for using the macros in DOS.INC and