! *** 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
    
    
    ! 
    !  CONDITION HANDLING ARGUMENT LIST OFFSETS
    !  THERE ARE FOUR CONDITIONAL HANDLING STRUCTURES: THE PRIMARY ARGUMENT
    !  LIST, THE SIGNAL AND MECHANISM ARRAYS AND THE ALPHA EXCEPTION RECORD
    !  ALL ARE IDENTIFIED BY THE SAME BLOCK PREFIX.
    ! 
      DECLARE LONG CONSTANT CHF$S_CHFDEF = 12
      record CHFDEF
         LONG CHFDEF$$_FILL_1               !  Primary Argument Count
         LONG CHF$L_SIGARGLST               ! ADDRESS OF SIGNAL ARGUMENTS 
         LONG CHF$L_MCHARGLST               ! ADDRESS OF MECHANISM ARGUMENTS
      end record CHFDEF
    
      DECLARE LONG CONSTANT CHF$S_CHFDEF1 = 12
      record CHFDEF1
         group CHF$R_SIG_ARGS_DESC
            variant
               case
                  LONG CHF$IS_SIG_ARGS      ! NUMBER OF SIGNAL ARGUMENTS
               case
                  LONG CHF$L_SIG_ARGS       ! obsolete def
            end variant
         end group CHF$R_SIG_ARGS_DESC
         group CHF$R_SIG_NAME_DESC
            variant
               case
                  LONG CHF$IS_SIG_NAME      ! SIGNAL NAME
               case
                  LONG CHF$L_SIG_NAME       ! obsolete def
            end variant
         end group CHF$R_SIG_NAME_DESC
         group CHF$R_SIG_ARG1_DESC
            variant
               case
                  LONG CHF$IS_SIG_ARG1      ! FIRST SIGNAL SPECIFIC ARGUMENT
               case
                  LONG CHF$L_SIG_ARG1       ! obsolete def
            end variant
         end group CHF$R_SIG_ARG1_DESC
      end record CHFDEF1
    
      DECLARE LONG CONSTANT CHF$M_FPREGS_VALID = x'00000001'
      DECLARE LONG CONSTANT CHF$M_FPREGS2_VALID = x'00000002'
      DECLARE LONG CONSTANT CHF$S_CHFDEF2 = 360
      record CHFDEF2
         group CHF$R_MCH_ARGS_DESC
            variant
               case
                  LONG CHF$IS_MCH_ARGS      ! NUMBER OF MECHANISM ARGUMENTS 
            end variant
         end group CHF$R_MCH_ARGS_DESC
         group CHF$R_MCH_FLAGS_DESC
            variant
               case
                  LONG CHF$IS_MCH_FLAGS     ! Flags
               case
                  group CHF$R_MCH_FLAGS_BITS  ! Flags bits.
                      ! FP registers stored in MCH.
                     BYTE FPREGS_VALID_bits   ! COMMENT ADDED BY SDL - FPREGS_VALID_bits contains bits FPREGS_VALID through  &
 ! FILL_75_
                  end group CHF$R_MCH_FLAGS_BITS
            end variant
         end group CHF$R_MCH_FLAGS_DESC
         group CHF$R_MCH_FRAME_DESC
            variant
               case
                  BASIC$QUADWORD CHF$PH_MCH_FRAME  ! ESTABLISHER FRAME ADDRESS 
            end variant
         end group CHF$R_MCH_FRAME_DESC
         group CHF$R_MCH_DEPTH_DESC
            variant
               case
                  LONG CHF$IS_MCH_DEPTH     ! FRAME DEPTH OF ESTABLISHER 
               case
                  LONG CHF$IH_MCH_DEPTH     ! temp
            end variant
         end group CHF$R_MCH_DEPTH_DESC
         LONG CHF$IS_MCH_RESVD1             ! reserved, paired with DEPTH
         BASIC$QUADWORD CHF$PH_MCH_DADDR    ! ESTABLISHER HANDLER DATA CELL
         BASIC$QUADWORD CHF$PH_MCH_ESF_ADDR  ! ESTABLISHER EXCEPTION STACK FRAME
         BASIC$QUADWORD CHF$PH_MCH_SIG_ADDR  ! ESTABLISHER EXCEPTION STACK FRAME
         group CHF$R_MCH_SAVR0_DESC
            variant
               case
                  BASIC$QUADWORD CHF$IH_MCH_RETVAL
               case
                  group CHF$R_FILL_71_
                     variant
                     case
                        BASIC$QUADWORD CHF$IH_MCH_SAVR0  ! SAVED REGISTER R0 
                     case
                        group CHF$R_FILL_72_
                           LONG CHF$IL_MCH_SAVR0_LOW  ! LOW ORDER 32 BITS
                           LONG CHF$IL_MCH_SAVR0_HIGH  ! HIGH ORDER 32 BITS
                        end group CHF$R_FILL_72_
                     end variant
                  end group CHF$R_FILL_71_
            end variant
         end group CHF$R_MCH_SAVR0_DESC
         group CHF$R_MCH_SAVR1_DESC
            variant
               case
                  BASIC$QUADWORD CHF$IH_MCH_RETVAL2
               case
                  group CHF$R_FILL_73_
                     variant
                     case
                        BASIC$QUADWORD CHF$IH_MCH_SAVR1  ! SAVED REGISTER R1 
                     case
                        group CHF$R_FILL_74_
                           LONG CHF$IL_MCH_SAVR1_LOW  ! LOW ORDER 32 BITS
                           LONG CHF$IL_MCH_SAVR1_HIGH  ! HIGH ORDER 32 BITS
                        end group CHF$R_FILL_74_
                     end variant
                  end group CHF$R_FILL_73_
            end variant
         end group CHF$R_MCH_SAVR1_DESC
         BASIC$QUADWORD CHF$IH_MCH_SAVR16   ! SAVED REGISTER R16
         BASIC$QUADWORD CHF$IH_MCH_SAVR17   ! SAVED REGISTER R17
         BASIC$QUADWORD CHF$IH_MCH_SAVR18   ! SAVED REGISTER R18
         BASIC$QUADWORD CHF$IH_MCH_SAVR19   ! SAVED REGISTER R19
         BASIC$QUADWORD CHF$IH_MCH_SAVR20   ! SAVED REGISTER R20
         BASIC$QUADWORD CHF$IH_MCH_SAVR21   ! SAVED REGISTER R21
         BASIC$QUADWORD CHF$IH_MCH_SAVR22   ! SAVED REGISTER R22
         BASIC$QUADWORD CHF$IH_MCH_SAVR23   ! SAVED REGISTER R23
         BASIC$QUADWORD CHF$IH_MCH_SAVR24   ! SAVED REGISTER R24
         BASIC$QUADWORD CHF$IH_MCH_SAVR25   ! SAVED REGISTER R25
         BASIC$QUADWORD CHF$IH_MCH_SAVR26   ! SAVED REGISTER R26
         BASIC$QUADWORD CHF$IH_MCH_SAVR27   ! SAVED REGISTER R27
         BASIC$QUADWORD CHF$IH_MCH_SAVR28   ! SAVED REGISTER R28
         group CHF$R_MCH_RETVAL_FLOAT
            variant
               case
                  BASIC$QUADWORD CHF$FH_MCH_SAVF0  ! SAVED REGISTER F0
               case
                  BASIC$QUADWORD CHF$FH_MCH_RETVAL_FLOAT
            end variant
         end group CHF$R_MCH_RETVAL_FLOAT
         group CHF$R_MCH_RETVAL2_FLOAT
            variant
               case
                  BASIC$QUADWORD CHF$FH_MCH_SAVF1  ! SAVED REGISTER F1
               case
                  BASIC$QUADWORD CHF$FH_MCH_RETVAL2_FLOAT
            end variant
         end group CHF$R_MCH_RETVAL2_FLOAT
         BASIC$QUADWORD CHF$FH_MCH_SAVF10   ! SAVED REGISTER F10
         BASIC$QUADWORD CHF$FH_MCH_SAVF11   ! SAVED REGISTER F11
         BASIC$QUADWORD CHF$FH_MCH_SAVF12   ! SAVED REGISTER F12
         BASIC$QUADWORD CHF$FH_MCH_SAVF13   ! SAVED REGISTER F13
         BASIC$QUADWORD CHF$FH_MCH_SAVF14   ! SAVED REGISTER F14
         BASIC$QUADWORD CHF$FH_MCH_SAVF15   ! SAVED REGISTER F15
         BASIC$QUADWORD CHF$FH_MCH_SAVF16   ! SAVED REGISTER F16
         BASIC$QUADWORD CHF$FH_MCH_SAVF17   ! SAVED REGISTER F17
         BASIC$QUADWORD CHF$FH_MCH_SAVF18   ! SAVED REGISTER F18
         BASIC$QUADWORD CHF$FH_MCH_SAVF19   ! SAVED REGISTER F19
         BASIC$QUADWORD CHF$FH_MCH_SAVF20   ! SAVED REGISTER F20
         BASIC$QUADWORD CHF$FH_MCH_SAVF21   ! SAVED REGISTER F21
         BASIC$QUADWORD CHF$FH_MCH_SAVF22   ! SAVED REGISTER F22
         BASIC$QUADWORD CHF$FH_MCH_SAVF23   ! SAVED REGISTER F23
         BASIC$QUADWORD CHF$FH_MCH_SAVF24   ! SAVED REGISTER F24
         BASIC$QUADWORD CHF$FH_MCH_SAVF25   ! SAVED REGISTER F25
         BASIC$QUADWORD CHF$FH_MCH_SAVF26   ! SAVED REGISTER F26
         BASIC$QUADWORD CHF$FH_MCH_SAVF27   ! SAVED REGISTER F27
         BASIC$QUADWORD CHF$FH_MCH_SAVF28   ! SAVED REGISTER F28
         BASIC$QUADWORD CHF$FH_MCH_SAVF29   ! SAVED REGISTER F29
         BASIC$QUADWORD CHF$FH_MCH_SAVF30   ! SAVED REGISTER F30
         BASIC$QUADWORD CHF$PH_MCH_SIG64_ADDR  ! 64-bit sig array ptr
      end record CHFDEF2
    
      DECLARE LONG CONSTANT CHF$M_CALEXT_CANCEL = x'00000001'
      DECLARE LONG CONSTANT CHF$M_CALEXT_LAST = x'00000002'
      DECLARE LONG CONSTANT CHF$K_CALEXT_LENGTH = 16  ! LENGTH OF CATCH-ALL DESC BLOCK
      DECLARE LONG CONSTANT CHF$C_CALEXT_LENGTH = 16  ! LENGTH OF CATCH-ALL DESC BLOCK
      DECLARE LONG CONSTANT CHF$S_CHFDEF3 = 16
      record CHFDEF3
         LONG CHF$L_CALEXT_LINK             ! CATCH-ALL EXTENSION LINK
         LONG CHF$L_CALEXT_ADDRESS          ! ADDRESS OF CATCH-ALL EXTENSION
         group CHF$R_CALEXT_FLAGS_DESC
            variant
               case
                  LONG CHF$L_CALEXT_FLAGS   ! FLAGS
               case
                  group CHF$R_CALEXT_FLAGS_BITS  ! FLAGS BITS
                      ! REMOVE CATCH-ALL EXTENSION
                      ! LAST CATCH-ALL EXTENSION
                     BYTE CALEXT_CANCEL_bits   ! COMMENT ADDED BY SDL - CALEXT_CANCEL_bits contains bits CALEXT_CANCEL through  &
 ! FILL_76_
                  end group CHF$R_CALEXT_FLAGS_BITS
            end variant
         end group CHF$R_CALEXT_FLAGS_DESC
         LONG CHF$L_CALEXT_RESERVED         ! RESERVED
      end record CHFDEF3
    
      DECLARE LONG CONSTANT CHF64$S_CHFDEF6 = 24
      record CHFDEF6
         group CHF64$R_SIG_ARGS_UNION
            variant
               case
                  LONG CHF64$L_SIG_ARGS     !  Longword including count ? options
               case
                  group CHF64$R_SIG_WORDS
                     WORD CHF64$W_SIG_ARG_COUNT  !  Word holding count itself
                     WORD CHF64$W_SIG_MSG_OPTIONS  !  Word containing message options
                  end group CHF64$R_SIG_WORDS
            end variant
         end group CHF64$R_SIG_ARGS_UNION
         LONG CHF64$L_SIGNAL64              !  64-bit array tag: overlays sig_name of 32b version
         BASIC$QUADWORD CHF64$Q_SIG_NAME    !  Signal value
         BASIC$QUADWORD CHF64$Q_SIG_ARG1    !  First signal argument
      end record CHFDEF6