p; The SC size is the dimensions
of the tile map; if using 8x8 tile mode, this allows BG dimensions of 256
or 512 pixels; if in 16x16 mode, the dimensions can be 512 or 1024 pixels.&nbsp;
Note that, since there is only 64K of VRAM, the most significant bit must
be zero.

<P>When using a screen size wider than 32 tiles, the format is a little
different than you might expect.&nbsp; When the width is 64 tiles, then
rather than each line in the tile map extending to 128 bytes (instead of
64), there will actuall