! *** 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 I/O Status Area
    ! -
      DECLARE LONG CONSTANT IOSA$K_LENGTH = 32  !  Length of IOSA
      DECLARE LONG CONSTANT IOSA$C_LENGTH = 32  !  Length of IOSA
      DECLARE LONG CONSTANT IOSA$S_IOSADEF = 32  !  Size of IOSA
      DECLARE LONG CONSTANT IOSA$S_IOSA = 32
      record IOSA
         group IOSA$R_IOSB_OVERLAY
            variant
               case
                  group IOSA$R_IOSB
                     WORD IOSA$W_IOSB_STATUS  !  Final I/O status
                     group IOSA$R_DEVDEPEND
                        variant
                        case
                           group IOSA$R_BCNT_16  !  16-bit byte count variant
                              WORD IOSA$W_IOSB_BCNT  !  16-bit byte count
                              group IOSA$r_l
                                 variant
                                 case
                                    LONG IOSA$L_IOSB_DEV_DEPEND  !  32-bit device dependent info
                                 case
                                    LONG IOSA$L_IOSB_PID  !  32-bit pid
                                 end variant
                              end group IOSA$r_l
                           end group IOSA$R_BCNT_16
                        case
                           group IOSA$R_BCNT_32  !  32-bit byte count variant
                              LONG IOSA$L_IOSB_BCNT  !  32-bit byte count (unaligned)
                              WORD IOSA$W_IOSB_DEV_DEPEND_HIGH  !  16-bit device dependent info
                           end group IOSA$R_BCNT_32
                        end variant
                     end group IOSA$R_DEVDEPEND
                  end group IOSA$R_IOSB
               case
                  group IOSA$R_STATUSQ
                     LONG IOSA$L_STATUS     !  Status
                     LONG IOSA$L_RESD       !  Reserved (driver)
                  end group IOSA$R_STATUSQ
            end variant
         end group IOSA$R_IOSB_OVERLAY
         group IOSA$R_BYTECOUNT
            variant
               case
                  BASIC$QUADWORD IOSA$Q_COUNT_Q  !  Force size
               case
                  BASIC$QUADWORD IOSA$IH_COUNT  !  Number of bytes
            end variant
         end group IOSA$R_BYTECOUNT
         group IOSA$R_CTX
            variant
               case
                  BASIC$QUADWORD IOSA$Q_CONTEXT_Q  !  Force size
               case
                  BASIC$QUADWORD IOSA$PH_CONTEXT_P  !  User context area
               case
                  BASIC$QUADWORD IOSA$IH_CONTEXT  !  User context area
               case
                  BASIC$QUADWORD IOSA$PH_UPDSEC_NOWRT_VA  !  First VA not written by $UPDSEC_64
            end variant
         end group IOSA$R_CTX
         group IOSA$R_RESERVED              !  Just in case we need
            variant
               case
                  LONG IOSA$L_RESL ( 1 to 2 )  !   in the future some
               case
                  BASIC$QUADWORD IOSA$Q_RESQ  !   additional space
               case
                  BASIC$QUADWORD IOSA$Q_CONTEXT_ID  !  User context ID
            end variant
         end group IOSA$R_RESERVED
      end record IOSA
    
    ! +
    !  $IO_SETUP flag bits
    ! -
      DECLARE LONG CONSTANT FIO$M_EXPEDITE = x'00000001'
      DECLARE LONG CONSTANT FIO$M_AST_NOFLOAT = x'00000002'
      DECLARE LONG CONSTANT FIO$M_CTX = x'00000004'
      DECLARE LONG CONSTANT FIO$S_SETUP_FLAGS = 4
      record SETUP_FLAGS
         variant
            case
               LONG FIO$L_FLAGS_LONGWORD
            case
               group FIO$R_FLAG_BITS
                   !  Make this a high-priority I/O
                   !  The AST routine does not use f.p. regs
                   !  Completion notification done via EFN$C_CTX
                  BYTE EXPEDITE_bits   ! COMMENT ADDED BY SDL - EXPEDITE_bits contains bits EXPEDITE through FILL_61_
               end group FIO$R_FLAG_BITS
         end variant
      end record SETUP_FLAGS