Map

Exterior map

Storage

The map (stored at $BCEE) is stored as a 54x34 grid of super tile indices. There are 218 of these super tiles (stored at $5B00) onwards. Each super tile in turn is a 4x4 grid of tile indices. Tiles are 8x8 pixel blocks.

There is a single exterior tile set (stored at $8590) of 571 8x8 tiles. Within the exterior tile set there are three groupings of tiles. A group is chosen based on which super tile is being plotted. This sliding window type approach lets super tiles borrow tiles from other groups if they're within range.

• Super tiles 0..44 use the tiles at the very start of the set
• Super tiles 45..138 and 204..217 use tiles 145 onwards
• Super tiles 139..203 use tiles 366 onwards

Here's the map again with the super tile groups highlighted respectively in yellow, green and cyan.

So the complete map is drawn using just the following tiles:

The total storage for the map is thus:

• (map) 54 * 34 + (super tiles) 218 * 4 * 4 + (tiles) 571 * 8 = 9,892 bytes

An uncompressed map not using such a scheme would consume:

• 54 * 32 * 34 * 32 / 8 = 235,008 bytes

Blank upper parts

The upper parts of the map are blank. Those sections of the map are never visible given the 192x128-sized viewport.

Super tiles

These are the 4x4 blocks of tile refs of which the exterior map is constructed.

$5B00/$00/1	$5B10/$01/1	$5B20/$02/1	$5B30/$03/1	$5B40/$04/1	$5B50/$05/1	$5B60/$06/1	$5B70/$07/1	$5B80/$08/1
$5B90/$09/1	$5BA0/$0A/1	$5BB0/$0B/1	$5BC0/$0C/1	$5BD0/$0D/1	$5BE0/$0E/1	$5BF0/$0F/1	$5C00/$10/1	$5C10/$11/1
$5C20/$12/1	$5C30/$13/1	$5C40/$14/1	$5C50/$15/1	$5C60/$16/1	$5C70/$17/1	$5C80/$18/1	$5C90/$19/1	$5CA0/$1A/1
$5CB0/$1B/1	$5CC0/$1C/1	$5CD0/$1D/1	$5CE0/$1E/1	$5CF0/$1F/1	$5D00/$20/1	$5D10/$21/1	$5D20/$22/1	$5D30/$23/1
$5D40/$24/1	$5D50/$25/1	$5D60/$26/1	$5D70/$27/1	$5D80/$28/1	$5D90/$29/1	$5DA0/$2A/1	$5DB0/$2B/1	$5DC0/$2C/1
$5DD0/$2D/2	$5DE0/$2E/2	$5DF0/$2F/2	$5E00/$30/2	$5E10/$31/2	$5E20/$32/2	$5E30/$33/2	$5E40/$34/2	$5E50/$35/2
$5E60/$36/2	$5E70/$37/2	$5E80/$38/2	$5E90/$39/2	$5EA0/$3A/2	$5EB0/$3B/2	$5EC0/$3C/2	$5ED0/$3D/2	$5EE0/$3E/2
$5EF0/$3F/2	$5F00/$40/2	$5F10/$41/2	$5F20/$42/2	$5F30/$43/2	$5F40/$44/2	$5F50/$45/2	$5F60/$46/2	$5F70/$47/2
$5F80/$48/2	$5F90/$49/2	$5FA0/$4A/2	$5FB0/$4B/2	$5FC0/$4C/2	$5FD0/$4D/2	$5FE0/$4E/2	$5FF0/$4F/2	$6000/$50/2
$6010/$51/2	$6020/$52/2	$6030/$53/2	$6040/$54/2	$6050/$55/2	$6060/$56/2	$6070/$57/2	$6080/$58/2	$6090/$59/2
$60A0/$5A/2	$60B0/$5B/2	$60C0/$5C/2	$60D0/$5D/2	$60E0/$5E/2	$60F0/$5F/2	$6100/$60/2	$6110/$61/2	$6120/$62/2
$6130/$63/2	$6140/$64/2	$6150/$65/2	$6160/$66/2	$6170/$67/2	$6180/$68/2	$6190/$69/2	$61A0/$6A/2	$61B0/$6B/2
$61C0/$6C/2	$61D0/$6D/2	$61E0/$6E/2	$61F0/$6F/2	$6200/$70/2	$6210/$71/2	$6220/$72/2	$6230/$73/2	$6240/$74/2
$6250/$75/2	$6260/$76/2	$6270/$77/2	$6280/$78/2	$6290/$79/2	$62A0/$7A/2	$62B0/$7B/2	$62C0/$7C/2	$62D0/$7D/2
$62E0/$7E/2	$62F0/$7F/2	$6300/$80/2	$6310/$81/2	$6320/$82/2	$6330/$83/2	$6340/$84/2	$6350/$85/2	$6360/$86/2
$6370/$87/2	$6380/$88/2	$6390/$89/2	$63A0/$8A/2	$63B0/$8B/3	$63C0/$8C/3	$63D0/$8D/3	$63E0/$8E/3	$63F0/$8F/3
$6400/$90/3	$6410/$91/3	$6420/$92/3	$6430/$93/3	$6440/$94/3	$6450/$95/3	$6460/$96/3	$6470/$97/3	$6480/$98/3
$6490/$99/3	$64A0/$9A/3	$64B0/$9B/3	$64C0/$9C/3	$64D0/$9D/3	$64E0/$9E/3	$64F0/$9F/3	$6500/$A0/3	$6510/$A1/3
$6520/$A2/3	$6530/$A3/3	$6540/$A4/3	$6550/$A5/3	$6560/$A6/3	$6570/$A7/3	$6580/$A8/3	$6590/$A9/3	$65A0/$AA/3
$65B0/$AB/3	$65C0/$AC/3	$65D0/$AD/3	$65E0/$AE/3	$65F0/$AF/3	$6600/$B0/3	$6610/$B1/3	$6620/$B2/3	$6630/$B3/3
$6640/$B4/3	$6650/$B5/3	$6660/$B6/3	$6670/$B7/3	$6680/$B8/3	$6690/$B9/3	$66A0/$BA/3	$66B0/$BB/3	$66C0/$BC/3
$66D0/$BD/3	$66E0/$BE/3	$66F0/$BF/3	$6700/$C0/3	$6710/$C1/3	$6720/$C2/3	$6730/$C3/3	$6740/$C4/3	$6750/$C5/3
$6760/$C6/3	$6770/$C7/3	$6780/$C8/3	$6790/$C9/3	$67A0/$CA/3	$67B0/$CB/3	$67C0/$CC/2	$67D0/$CD/2	$67E0/$CE/2
$67F0/$CF/2	$6800/$D0/2	$6810/$D1/2	$6820/$D2/2	$6830/$D3/2	$6840/$D4/2	$6850/$D5/2	$6860/$D6/2	$6870/$D7/2
$6880/$D8/2	$6890/$D9/2

Unused super tiles

Super tiles $4F (wall variant) and $9A (grassy tunnel exit) are unused.