HHPOSR

         BIT#  15  14  13  12  11  10  09  08  07  06  05  04  03  02  01  00
                x   x   x   x   x   x   x   x  h8  h7  h6  h5  h4  h3  h2  h1


         This the secondary beam counter for
         the faster mode, triggering the UHRES pointers & doing the
         comparisons for HBSTRT, HBSTOP, HTOTAL, HSSTRT, HSSTOP