NAME   rev ADDR type chip Description
---------------------------------------------------------------------------
HBSTOP 1C6 W  D    Horizontal STOP position
HBSTRT 1C4 W  D    Horizontal START position

	 Bits 7-0 contain the stop and start positions,
	 respectively, for programed horizontal blanking in
	 280nS increments.Bits 10-8 provide a fine position
	 control in 35nS increments.


         +-------+----------+--------------+
         | BIT#  | FUNCTION | DESCRIPTION  |
         +-------+----------+--------------+
         | 15-11 |  x       | (unused)     |
         | 10    |  H1      | 140nS        |
         | 09    |  H1      | 70nS         |
         | 08    |  H0      | 35nS         |
         | 07    |  H10     | 35840nS      |
         | 06    |  H9      | 17920nS      |
         | 05    |  H8      | 8960nS       |
         | 04    |  H7      | 4480nS       |
         | 03    |  H6      | 2240nS       |
         | 02    |  H5      | 1120nS       |
         | 01    |  H4      | 560nS        |
         | 00    |  H3      | 280nS        |
         +-------+----------+--------------+