The full command-line option is /[NO]DEFINE=(symbol [=
    [=]value],...).
    Performs the same function as direct symbol assignment in your
    source program. That is, the /DEFINE qualifier defines a numeric
    symbol.
    The Digital Command Language (DCL) converts all input to
    uppercase unless you enclose it within quotation marks.
    Use a single equal sign between the symbol and the value to
    define a local symbol. Use two equal signs between the symbol and
    the value to define a global symbol. The final value of a global
    symbol is output to the object module and is available during
    the linking process. A local symbol is only available during the
    assembly process.
    You cannot define a lexical string symbol with /DEFINE. The value
    you specify for a symbol must be an integer literal. You can
    specify this value using a binary, octal, decimal, or hexadecimal
    radix. The default radix is decimal. If you specify an alternate
    radix, you must use MACRO-64 radix syntax, not DCL radix syntax.
    If you do not specify a value for the symbol, it defaults to 1.
    The simplest form of a /DEFINE definition is as follows:
             /DEFINE=TRUE
    This definition is equivalent to the following definition:
             TRUE=1
    You can also specify more than one symbol definition as with the
    following command:
             /DEFINE=(CHIP==21064,UNROLL=4)
    This definition is equivalent to the following definitions:
             CHIP==21064
             UNROLL=4
    When more than one /DEFINE qualifier is present on the MACRO
    command line or in a single assembly unit, the assembler uses
    only the last one.
    The default qualifier is /NODEFINE.