How to delete ready-made background instructions from bank $8F: ready-made backgrounds are very simple because of how limited they are in size, so most people prefer to use layer 2 backgrounds instead. If you decide that you're simply never gonna use the ready-made backgrounds at all, you can replace their instructions in bank $8F with free space, which can be then used for additional headers, pointer data, etc. If you delete a background's instructions, make certain that no room has a background pointer that points to it anymore, or else the room will crash. In HxD, all you need to do is select the "Block" PC addresses/offsets listed below and replace them with FF. For example, the background pointer B76A that's used by room 791F8. To delete that background's instructions, you would go to the offset 7B76A, block select 7B76A-7B7AD, then right-click > "Fill Selection ..." > check the "Hex Values" checkbox and type FF in place of the 00 that's there by default > click OK. Doing this changes all selected bytes into FF, and now you can save the ROM. You'll obviously need to change the room's background pointer from B76A to 0000 in SMILE after you do this, then do the same for any other rooms using B76A. The actual tilemaps for the backgrounds are located in banks $B9 and $BA. List of ready-made Background pointer layering instructions: CRATERIA: B76A - Block: 7B76A-7B7AD; Length: 44 B7AE - Block: 7B7AE-7B7F1; Length: 44 B7F2 - Block: 7B7F2-7B809; Length: 18 B80A - Block: 7B80A-7B814; Length: 0B B87E - Block: 7B87E-7B898; Length: 1B B899 - Block: 7B899-7B8B3; Length: 1B B8B4 - Block: 7B8B4-7B8CE; Length: 1B B8CF - Block: 7B8CF-7B8E9; Length: 1B B8EA - Block: 7B8EA-7B904; Length: 1B B905 - Block: 7B905-7B91F; Length: 1B B920 - Block: 7B920-7B93A; Length: 1B B93B - Block: 7B93B-7B955; Length: 1B B956 - Block: 7B956-7B970; Length: 1B BB60 - Block: 7BB60-7BB7A; Length: 1B BCA4 - Block: 7BCA4-7BCB5; Length: 1B BRINSTAR: B815 - Block: 7B815-7B83F; Length: 2B B840 - Block: 7B840-7B84C; Length: 0D BA37 - Block: 7BA37-7BA51; Length: 1B BA52 - Block: 7BA52-7BA6C; Length: 1B BA6D - Block: 7BA6D-7BA87; Length: 1B BA88 - Block: 7BA88-7BAA2; Length: 1B BAA3 - Block: 7BAA3-7BABD; Length: 1B BABE - Block: 7BABE-7BAD8; Length: 1B BAD9 - Block: 7BAD9-7BAFE; Length: 1B BAF4 - Block: 7BAF4-7BB0E; Length: 1B BB0F - Block: 7BB0F-7BB29; Length: 1B BB2A - Block: 7BB2A-7BB44; Length: 1B BB45 - Block: 7BB45-7BB5F; Length: 1B BB7B - Block: 7BB7B-7BB95; Length: 1B BB96 - Block: 7BB96-7BBB0; Length: 1B BBB1 - Block: 7BBB1-7BBCB; Length: 1B BBCC - Block: 7BBCC-7BBE6; Length: 1B BBE7 - Block: 7BBE7-7BC01; Length: 1B BC02 - Block: 7BC02-7BC1C; Length: 1B BC1D - Block: 7BC1D-7BC37; Length: 1B BC38 - Block: 7BC38-7BC52; Length: 1B BC53 - Block: 7BC53-6BC6D; Length: 1B BC6E - Block: 7BC6E-7BC88; Length: 1B BC89 - Block: 7BC89-7BCA3; Length: 1B BCB6 - Block: 7BCB6-7BCD0; Length: 1B BCD1 - Block: 7BCD1-7BCEB; Length: 1B BCEC - Block: 7BCEC-7BD06; Length: 1B NORFAIR: B84D - Block: 7B84D-7B857; Length: 0B B858 - Block: 7B858-7B87D; Length: 26 BE3F - Block: 7BE3F-7BE59; Length: 1B BE5A - Block: 7BE5A-7BE74; Length: 1B BE75 - Block: 7BE75-7BE8F; Length: 1B BE90 - Block: 7BE90-7BEAA; Length: 1B BEAB - Block: 7BEAB-7BEC5; Length: 1B BEC6 - Block: 7BEC6-7BEE0; Length: 1B BEE1 - Block: 7BEE1-7BEFB; Length: 1B BEFC - Block: 7BEFC-7BF16; Length: 1B BF17 - Block: 7BF17-7BF31; Length: 1B BF32 - Block: 7BF32-7BF4C; Length: 1B BF4D - Block: 7BF4D-7BF67; Length: 1B BF68 - Block: 7BF68-7BF82; Length: 1B BF83 - Block: 7BF83-7BF9D; Length: 1B WRECKED SHIP: E0FD - Block: 7E0FD-7E107; Length: 0B E117 - Block: 7E117-7E131; Length: 1B E132 - Block: 7E132-7E14C; Length: 1B E14D - Block: 7E14D-7E167; Length: 1B E168 - Block: 7E168-7E182; Length: 1B E183 - Block: 7E183-7E19D; Length: 1B E19E - Block: 7E19E-7E1B8; Length: 1B E1B9 - Block: 7E1B9-7E1D3; Length: 1B MARIDIA: E108 - Block: 7E108-7E112; Length: 0B E113 - Block: 7E113-7E116; Length: 04 E248 - Block: 7E248-7E259; Length: 02 E25A - Block: 7E25A-7E26B; Length: 12 TOURIAN: E3E8 - Block: 7E3E8-7E402; Length: 1B E403 - Block: 7E403-7E41D; Length: 1B E41E - Block: 7E41E-7E438; Length: 1B E439 - Block: 7E439-7E453: Length: 1B E454 - Block: 7E454-7E46E; Length: 1B E46F - Block: 7E46F-7E489; Length: 1B E48A - Block: 7E48A-7E4A4; Length: 1B CERES: E1D4 - Block: 7E1D4-7E1D7; Length: 04 E4A5 - Block: 7E4A5-7E4BF; Length: 1B DEBUG (unused): E85B - Block: 7E85B-7E87E; Length: 24