>$212B&nbsp; ????ccss&nbsp; c: Color windows&nbsp;&nbsp;&nbsp; s:
Sprites</TT>

<P><TT>Each of the two bits for each BG and sprites determines the mask
logic as follows:</TT>

<P><TT>00&nbsp; OR&nbsp;&nbsp;&nbsp;&nbsp; 10 XOR</TT>
<BR><TT>01&nbsp; AND&nbsp;&nbsp;&nbsp; 11 XNOR</TT>

<P>Apparently, these registers apply only for BGs and sprites that have
both windows enabled at the same time.&nbsp; If only one window is enabled,
these bits should be ignored.&nbsp; I'm not sure whether the logic is applied
to