HTOTAL

         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


         (x`s should be driven to 0 for upward compatibility)
         Horiz line has this many + 1 280nS increments. If the
         pal bit & LOLDIS are not high, long line/short line toggle
         will occur, and there will be this many + 2 every other line.
         Active if VARBEAMEN=1 or DUAL=1.