TYPEDEF          Define named type                                  Directive

  TYPEDEF type_name complex_type        ; Ideal mode
  type_name TYPEDEF complex_type        ; MASM mode

    Defines a named type. Named types represent simple or complex types.

    When you use a named type in an expression, it functions as if it were
    a simple type of the appropriate size.

    Example:    mov   ax,[word ptr bx]      ; Simple statement
                TYPEDEF foo near ptr byte   ; foo is basically a word
                mov   ax,[foo ptr bx]       ;    so this works too