STACK            Define stack segment                               Directive

  STACK [size]                          ; Ideal or MASM mode
  .STACK [size]                         ; MASM mode only

    Begins or continues a module's stack segment. The optional size
    parameter specifies the amount of stack to reserve, in bytes. If you
    don't specify a size, the default is 400h bytes (1,024 bytes). This
    directive is usually used with the other simplified segment directives
    (such as CODESEG and DATASEG). To use STACK, you must have defined the
    memory model with MODEL (other than model tiny).

    In MASM mode, any labels, code, or data following the STACK statement
    will not be considered part of the stack segment. Ideal mode, however,
    reserves the specified space, and leaves the stack segment open so
    that you can add labels or other uninitialized data.

    You usually only need to use the STACK directive if you are writing a
    stand-alone assembly language program; most high-level languages will
    create a stack for you.