bsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; h: horizontal counter enable&nbsp; j: joypad enable</PRE>
n and j must be set to enable NMI interrupts and the joypad.&nbsp; Not
sure of the exact effects of bits 4 and 5, but they probably must be set
to enable IRQ interrupts.

<P><A NAME="Reg4207"></A><A NAME="Reg4209"></A><B><FONT FACE="Lucida Console">Register
$4207/$4208 &amp; $4209/$420A: Horizontal/Vertical IRQ trigger counters
(2*2b/W)</FONT></B>
<PRE>For each register:
???????l llllllll&nbsp; l: location to 