What                 Boards   Address(es) description          cleared by        notes
   Video SYNC Crashlock 2-9      5004        2 16 bit counters    write to address
   VIC Resync Counts    3-7      1014        16 bit cntr PGM      write to address
                                 1018        16 bit cntr PST      write to address  not valid on 4-7
                                 101C        16 bit cntr PVW      write to address
   LVDS A               2-9      3040        12 bit cntr LVDSA    write to address
   LVDS B               2-9      3044        12 bit cntr LVDSB    write to address
   LVDS C               2-9      3048        12 bit cntr LVDSC    write to address
   LVDS D               2-9      304C        12 bit cntr LVDSD    write to address
   P2P OUT A            2-9      3050        12 bit cntr P2PO-A   write to address
   P2P OUT B            2-9      3054        12 bit cntr P2PO-B   write to address
   P2P IN  A            2-9      3060        12 bit cntr P2PI-A   write to address
   P2P IN  B            2-9      3064        12 bit cntr P2PI-B   write to address
*/