Memory Map:


$2000 -- code

$9000 -- tiles
$9400 -- global tilemap
$BC00 -- local tilemap subset
$BD00 -- unused
$C000 -- ROM


Memory map:
	$0000-$00ff = zero page
	$0100-$01ff = stack
	$0200-$03ff = ???
	$0400-$07ff = lo-res page1
	$0800-$0bff = lo-res page2
	$0c00-$0fff = background image
	$1000-$1fff = loader
	$2000-????? = code
	$9000-$93ff = tiles		(1k)
	$9400-????? = big_tilemap	(10k)
	$BC00-????? = tilemap		(1k) 10x16 

tiles are 2x4, or 4 bytes each
	so in theory can have up to 256 of them
	in 16x16 grid
	tilemap is 256 wide by 40 tall = 10k

Tiles:
	hard tiles start at 32

