NAME rev ADDR type chip Description --------------------------------------------------------------------------- HHPOSR H 1DA R A DUAL mode hires Hbeam counter read HHPOSW H 1D8 W A DUAL mode hires Hbeam counter write This the secondary beam counter for the faster mode, triggering the UHRES pointers & doing the comparisons for HBSTRT, STOP, HTOTAL, HSSRT, HSSTOP (See HTOTAL for bits)