! *** PREDECLARED TYPES
     
      %IF %DECLARED ( %BASIC$QUADWORD_DECLARED ) = 0 %THEN
         RECORD BASIC$QUADWORD
            LONG FILL ( 2 )
         END RECORD
         %LET %BASIC$QUADWORD_DECLARED = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$OCTAWORD_DECLARED ) = 0 %THEN
         RECORD BASIC$OCTAWORD
            LONG FILL ( 4 )
         END RECORD
         %LET %BASIC$OCTAWORD_DECLARED = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$HFLOAT_AXP_DECLARED ) = 0 %THEN
         RECORD BASIC$HFLOAT_AXP
            LONG FILL ( 4 )
         END RECORD
         %LET %BASIC$HFLOAT_AXP_DECLARED = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$F_FLOATING_COMPLEX_DECL ) = 0 %THEN
         RECORD BASIC$F_FLOATING_COMPLEX
            SINGLE REAL_PART
            SINGLE IMAGINARY_PART
         END RECORD
         %LET %BASIC$F_FLOATING_COMPLEX_DECL = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$D_FLOATING_COMPLEX_DECL ) = 0 %THEN
         RECORD BASIC$D_FLOATING_COMPLEX
            DOUBLE REAL_PART
            DOUBLE IMAGINARY_PART
         END RECORD
         %LET %BASIC$D_FLOATING_COMPLEX_DECL = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$G_FLOATING_COMPLEX_DECL ) = 0 %THEN
         RECORD BASIC$G_FLOATING_COMPLEX
            GFLOAT REAL_PART
            GFLOAT IMAGINARY_PART
         END RECORD
         %LET %BASIC$G_FLOATING_COMPLEX_DECL = 1
      %END %IF
     
      %IF %DECLARED ( %BASIC$H_FLOAT_AXP_CMPLX_DCL ) = 0 %THEN
         RECORD BASIC$H_FLOATING_COMPLEX_AXP
            BASIC$HFLOAT_AXP REAL_PART
            BASIC$HFLOAT_AXP IMAGINARY_PART
         END RECORD
         %LET %BASIC$H_FLOAT_AXP_CMPLX_DCL = 1
      %END %IF
    
    
    ! +
    !  Define the version level of the FDL file structure
    ! -
      DECLARE LONG CONSTANT FDL$C_VERSION = 2
      DECLARE LONG CONSTANT FDL$K_VERSION = 2
    ! +
    !  FDL CALL INTERFACE CONTROL FLAGS
    ! -
      DECLARE LONG CONSTANT FDL$M_SIGNAL = x'00000001'
      DECLARE LONG CONSTANT FDL$M_FDL_STRING = x'00000002'
      DECLARE LONG CONSTANT FDL$M_DEFAULT_STRING = x'00000004'
      DECLARE LONG CONSTANT FDL$M_FULL_OUTPUT = x'00000008'
      DECLARE LONG CONSTANT FDL$M_$CALLBACK = x'00000010'
      DECLARE LONG CONSTANT FDL$M_LONG_NAMES = x'00000020'
      DECLARE LONG CONSTANT FDL$S_FDLDEF = 1
      record FDLDEF
         variant
            case
               group FDL$R_FDLDEF_BITS
                   !  SIGNAL ERRORS, DON'T RETURN
                   !  MAIN FDL SPEC IS A CHAR STRING
                   !  DEFAULT FDL SPEC IS A CHAR STRING
                   !  PRODUCE A 'COMPLETE' FDL SPEC
                   !  USED BY EDF ON INPUT (DEC ONLY)
                   !  Allocate and use NAML for FDL$PARSE
                  BYTE SIGNAL_bits   ! COMMENT ADDED BY SDL - SIGNAL_bits contains bits SIGNAL through FILL_0_
               end group FDL$R_FDLDEF_BITS
         end variant
      end record FDLDEF