4.3.1 Steering block /ZASTE/

      LOGICAL FIRST,                ! TRUE if very first call to analysing
                                    ! code
     .        DOWNUP,               ! vertex-fit method : include tracks
                                    ! until Xi^2 becomes bad (.TRUE.), or
                                    ! exclude tracks until it becomes good
                                    ! (.FALSE.)
     .        VTXGEN,               ! TRUE if main vertex position variations
                                    ! were generated, FALSE otherwise.
     .        DST,                  ! TRUE if data comes from full
                                    ! simulation or real data
     .        REAL_DATA             ! TRUE if real data
      INTEGER
     .        EVT,                  ! current event number
     .        IGEOM,                ! present detector geometry
     .        LUNPR,                ! print unit
     .        MAXPR,                ! max number of events to print
     .        MINJET,               ! min number of jets to accept event
     .        NWBHIT(10),           ! Number of words used for barrel hit-
                                    ! list
     .        NWFHIT(10)            ! Number of words used for forward hit-
                                    ! list
      REAL
     .        SSEPL,                ! Limiting probability for two
                                    ! showers to be separable in
                                    ! calorimeters
     .        MSTCA                 ! Lowest distance between shower
                                    ! start-point and track extrapolation
                                    ! to calorimeter at which the shower
                                    ! will not be attached to the track