anchor.diff:              ED_Start     = Indx_u_ED_Platform_Start(u_ED, y_FAST) ! start of u_ED%PlatformPtMesh%TranslationDisp field
               call Assemble_dUdy_Loads(HD%y%AllHdroOrigin, u_ED%PlatformPtMesh, MeshMapData%HD_W_P_2_ED_P, ED_Start, HD_Out_Start, dUdy)
            end if
  +         
  +            ! ED translation displacement-to-ED moment transfer (dU^{ED}/dy^{ED}):
  +         ED_Start = Indx_u_ED_Platform_Start(u_ED, y_FAST) + u_ED%PlatformPtMesh%NNodes*3   ! start of u_ED%PlatformPtMesh%Moment field (skip the ED forces)
  +         ED_Out_Start = Indx_y_ED_Platform_Start(y_ED, y_FAST) ! start of y_ED%PlatformPtMesh%TranslationDisp field
  +         call SetBlockMatrix( dUdy, MeshMapData%HD_W_P_2_ED_P%dM%m_uD, ED_Start, ED_Out_Start )
  +
  +            
      end if
      
      ! MAP
  +   ! parts of dU^{ED}/dy^{MAP} and dU^{ED}/dy^{ED}:
      if ( p_FAST%CompMooring == Module_MAP ) then
         if ( MAPp%y%ptFairleadLoad%Committed  ) then ! meshes for floating
            !!! ! This linearization was done in forming dUdu (see Linear_ED_InputSolve_du()), so we don't need to re-calculate these matrices 
  
positive.code:          ED_Start      = Indx_u_ED_Platform_Start(u_ED, y_FAST) ! start of u_ED%PlatformPtMesh%TranslationDisp field
           call Assemble_dUdy_Loads(MAPp%y%ptFairLeadLoad, u_ED%PlatformPtMesh, MeshMapData%Mooring_P_2_ED_P, ED_Start, MAP_Out_Start, dUdy)
        end if
     end if
     
  END SUBROUTINE Linear_ED_InputSolve_dy
  
negative.code:       ED_Start = Indx_u_ED_Hub_Start(u_ED, y_FAST) + u_ED%HubPtLoad%NNodes*3 ! start of u_ED%HubPtLoad%Moment field (skip forces)
        DO k=1,p_FAST%nBeams
           ED_Out_Start = Indx_y_ED_BladeRoot_Start(y_ED, y_FAST, k) ! start of y_ED%BladeRootMotion(k)%TranslationDisp field
           call SumBlockMatrix( dUdy, MeshMapData%BD_P_2_ED_P(k)%dM%m_ud, ED_Start, ED_Out_Start)
        END DO
  
     END IF
  
     ! HD
     ! parts of dU^{ED}/dy^{HD} and dU^{ED}/dy^{ED}:
     if ( p_FAST%CompHydro == Module_HD ) then ! HydroDyn-{ElastoDyn or SubDyn}
              
              ! we're just going to assume u_ED%PlatformPtMesh is committed
  