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_______________________________________ Room index
| ____________________________________ Area index
| | _________________________________ X position (of top left corner) on the map
| | | ______________________________ Y position (of top left corner) on the map
| | | | ___________________________ Room width (in units of screens = 16 blocks = 256 pixels)
| | | | | ________________________ Room height (in units of screens = 16 blocks = 256 pixels)
| | | | | | _____________________ Up scroller
| | | | | | | __________________ Down scroller
| | | | | | | | _______________ CRE bitset
| | | | | | | | | ____________ Door list pointer
| | | | | | | | | | _______ Optional event headers
| | | | | | | | | | | _ Mandatory event header, specifies that the default state follows this room header
| | | | | | | | | | | |
ii aa xx yy ww hh uu dd cc dddd [...] E5E6
Room headers define rooms, they exist in bank $8F and room header pointers are what SMILE displays as a dropdown box for room selection.
They are variable length (due to the optional event headers) with E5E6
as an effective terminator.
The event headers define conditions to load alternative state headers, they are checked in order and the first event header whose check passes is to determine the state header to load.
Due to this, event headers must be specified in backwards chronological order.
0 | Crateria |
1 | Brinstar |
2 | Norfair |
3 | Wrecked Ship |
4 | Maridia |
5 | Tourian |
6 | Ceres |
7 | Debug |
Notes:
The room index is almost unused, aside from some specific checks to do with atmospheric graphics in some areas.
The room width may not exceed 15 due to the way block collision calculations are implemented
Room width * room height may not exceed 0x50 due to memory constraints
The up scroller defines the threshold Y position that Samus needs to exceed (relative to the screen) for the screen to start scolling downwards when the camera is at the top of the room
The down scroller defines the threshold Y position that Samus needs to exceed (relative to the screen) for the screen to start scolling upwards when the camera is at the bottom of the room
The CRE bitset defines some flags that affect how the CRE is loaded during door transitions:
1 | Disable layer 1 during door transitions into and out of the room |
2 | Reload the CRE |
4 | Load extra large tileset |
____________ Event
| _______ Event parameters
| | _ State header pointer
| | |
eeee [...] ssss
Events are two-byte pointers to code in bank $8F that may have parameters depending on the event in question.
If the check defined in the event is passed, the state header pointer for that event is used to load the room.
The only exception is event $E5E6, the default event, which doesn't have a state header pointer (the default state header simply follows this event header instead).
List of events used in Super Metroid
List of events used in Super Metroid
Event | Event parameters | Description |
$E5E6 | | Default |
$E5EB | dddd | Check passes if the current door pointer = d |
$E5FF | | Check passes if main area boss is dead |
$E612 | ee | Check passes if event e is set |
$E629 | bb | Check passes if area boss b is dead |
$E640 | | Check passes if morph ball has been collected |
$E652 | | Check passes if morph ball and missiles have been collected |
$E669 | | Check passes if power bombs have been collected |
$E678 | | Check passes if speed booster has been collected |
Event numbers are given as follows:
00 | Zebes is awake |
01 | Shitroid ate sidehopper |
02 | Mother Brain's glass is broken |
03 | Zebetite 1 is destroyed |
04 | Zebetite 2 is destroyed |
05 | Zebetite 3 is destroyed |
06 | Phantoon statue is grey |
07 | Ridley statue is grey |
08 | Draygon statue is grey |
09 | Kraid statue is grey |
0A | Entrance to Tourian is unlocked |
0B | Maridia noobtube is broken |
0C | Lower Norfair chozo has lowered the acid |
0D | Shaktool cleared a path |
0E | Zebes timebomb set |
0F | Critters escaped |
10 | 1st Metroid hall cleared |
11 | 1st Metroid shaft cleared |
12 | 2nd Metroid hall cleared |
13 | 2nd Metroid shaft cleared |
14 | Unused |
15 | Outran speed booster lavaquake |
Boss bits are given as follows:
1 | Area boss (Kraid, Phantoon, Draygon, both Ridleys) |
2 | Area mini-boss (Spore Spawn, Botwoon, Crocomire, Mother Brain) |
4 | Area torizo (Bomb Torizo, Golden Torizo) |
Door list
_________________ First door pointer (door BTS 0)
| ____________ Second door pointer (door BTS 1)
| | _______ Other door pointerd (door BTS 2+)
| | |
aaaa bbbb [...]
Door lists are a list of door pointers that can be used in a room, they exist in bank $8F.
They are variable length with no terminator, and are indexed by door BTS (thus, there is an effective maximum of 128 door pointers).
The door pointers themselves are two-byte pointers to door headers in bank $83.
_____________________________ Destination room header pointer (bank $8F)
| ________________________ Elevator properties
| | _____________________ Orientation
| | | __________________ X position low byte
| | | | _______________ Y position low byte
| | | | | ____________ X position high byte
| | | | | | _________ Y position high byte
| | | | | | | ______ Distance from door to spawn Samus
| | | | | | | | _ Custom door ASM to execute (bank $8F)
| | | | | | | | |
rrrr ee oo xx yy XX YY dddd aaaa
Door headers define doors, they exist in bank $83 and have a fixed length of 12 bytes.
The door ASM can execute any arbitrary ASM and is often used to set scroll values for the new room where the door would normally be hidden inside a red scroll.
The elevator properties are as follows:
0x80 | Door is an elevator |
0x40 | Switch map to new area |
0x0i | Marks elevator i as used |
The orientation values are as follows:
0 | Right |
1 | Left |
2 | Down |
3 | Up |
4+ | Door spawns a closing door cap |
_______________________________________________________________ Level data
| ________________________________________________________ Tileset
| | _____________________________________________________ Music data index
| | | __________________________________________________ Music track
| | | | _______________________________________________ FX ($83)
| | | | | __________________________________________ Enemy population ($A1)
| | | | | | _____________________________________ Enemy set ($B4)
| | | | | | | ________________________________ Layer 2 scroll X
| | | | | | | | _____________________________ Layer 2 scroll Y
| | | | | | | | | ________________________ Scroll
| | | | | | | | | | __________________ Special x-ray blocks
| | | | | | | | | | | ______________ Main ASM (FX2 in old SMILE)
| | | | | | | | | | | | _________ PLM population
| | | | | | | | | | | | | ____ Library background
| | | | | | | | | | | | | | _ Setup ASM (Layer1_2 in old SMILE)
| | | | | | | | | | | | | | |
llllll tt MM mm ffff eeee EEEE xx yy ssss xxxx AAAA pppp bbbb aaaa
State headers define the parts of rooms that can change due to different events.
0 | Upper Crateria |
1 | Red Crateria |
2 | Lower Crateria |
3 | Old Tourian |
4 | Wrecked Ship - power on |
5 | Wrecked Ship - power off |
6 | Green/blue Brinstar |
7 | Red Brinstar / Kraid's lair |
8 | Pre Tourian entrance corridor |
9 | Heated Norfair |
Ah | Unheated Norfair |
Bh | Sandless Maridia |
Ch | Sandy Maridia |
Dh | Tourian |
Eh | Mother Brain's room |
Fh | Blue Ceres |
10h | White Ceres |
11h | Blue Ceres elevator |
12h | White Ceres elevator |
13h | Blue Ceres Ridley's room |
14h | White Ceres Ridley's room |
15h | Map room / Tourian entrance |
16h | Wrecked Ship map room - power off |
17h | Blue refill room |
18h | Yellow refill room |
19h | Save room |
1Ah | Kraid's room |
1Bh | Crocomire's room |
1Ch | Draygon's room |
0 | No change |
3 | Title sequence |
6 | Empty Crateria |
9 | Lower Crateria |
Ch | Upper Crateria |
Fh | Green Brinstar |
12h | Red Brinstar |
15h | Upper Norfair |
18h | Lower Norfair |
1Bh | Maridia |
1Eh | Tourian |
21h | Mother Brain |
24h | Boss fight 1 |
27h | Boss fight 2 |
2Ah | Miniboss fight |
2Dh | Ceres |
30h | Wrecked Ship |
33h | Zebes boom |
36h | Intro |
39h | Death |
3Ch | Credits |
3Fh | “The last Metroid is in captivity” |
42h | “The galaxy is at peace” |
45h | Shitroid (same as boss fight 2) |
48h | Samus theme (same as upper Crateria) |
0 | No change |
1 | Samus fanfare |
2 | Item fanfare |
3 | Elevator |
4 | Pre-statue hall |
5 | Song 0 |
6 | Song 1 |
7 | Song 2 |
Notes:
Level data is a three-byte pointer to compressed data defining the placement of layer 1 tiles, block properties (including BTS) and optionally custom layer 2 tile placement
The tileset is an index into a table that defines the tile table, tile graphics and palette
The music data index is an index into a music pointers that define songs 0, 1 and 2
The FX is an (optional) pointer to data defining graphical effects such as animated tiles, palette glows and layer 3 (e.g. water, lava, spores)
The enemy population is a pointer to data defining enemy placement and other parameters
The enemy set is a pointer to data defining which enemies use which palettes
The layer 2 scroll X/Y is a value that determines whether or not custom layer 2 is used, and how fast layer 2 scrolls compared to layer 1 (parallax effect)
In binary, let layer 2 scroll X/Y = sssssssb
If b
= 1, then the library background is used, otherwise custom layer 2 (defined in level data) is used
s
= 0 is a special case that depends on b
If b
= 0 (custom layer 2), then layer 2 and layer 1 scroll together at the same speed (like an extension of layer 1)
If b
= 1 (library background), then layer 2 does not scroll at all (static image background)
Otherwise (if s
!= 0), layer 2 scroll speed = (layer 1 scroll speed) * (s
/ 0x80)
The scroll is an (optional) pointer to data defining which 16×16 regions are scrollable
If scroll = 0, then every scroll region is set to green, except for the bottom row, which is set to blue
If scroll = 1, then every scroll region is set to green
The special x-ray blocks is an (optional) pointer to data defining custom x-ray block graphics
The main ASM is an (optional) pointer to code run every frame
The PLM population is an (optional) pointer to data defining PLM placement and parameters
The library background is an (optional) pointer to data defining operations for loading layer 2
The setup ASM is an (optional) pointer to code run upon loading the room
Level data
ssssssssssssssss ; Size of decompressed layer 1 data (2 x the number of blocks)
_______ Block type
| ___ Y flip
| | __ X flip
| || _ Block number
| |||
ttttyxnnnnnnnnnn ; First block
ttttyxnnnnnnnnnn ; Second block
[...] ; Other blocks
ttttyxnnnnnnnnnn ; Last block
bbbbbbbb ; First block BTS
bbbbbbbb ; Second block BTS
[...]
bbbbbbbb ; Last block BTS
Optional:
0000yxnnnnnnnnnn ; First block layer 2
0000yxnnnnnnnnnn ; Second block layer 2
[...] ; Other blocks layer 2
0000yxnnnnnnnnnn ; Last block layer 2
Level data is defined by specifying data for each 16px x 16px block in the room.
This data is split into layer 1 blocks, BTS and optionally layer 2 blocks.
Layer 1/2 are two bytes per block, BTS is one byte per block, and a two byte “decompressed layer 1” size.
The decompressed size is followed by layer 1 data, followed by BTS, followed by layer 2 (if used) in that order.
Level data is compressed in ROM.
Layer 1 blocks uses the binary format shown above where:
Block type specifies the primary type of the block
X/Y flip flips the graphics of the block
Block number specifies the index of the block into the tile table (provides the graphics of the block)
Layer 2 blocks use the same format, except that they have no block type (they are padded with zeros instead).
BTS data further specifies the type of a block, depending on the primary block type used, e.g. different slope types.
Block types and BTS values
Block types and BTS values
Air types | Solid types |
0 | Air | 8 | Solid block |
1 | Slope | 9 | Door block |
2 | Spike air | Ah | Spike block |
3 | Special air | Bh | Special block |
4 | Shootable air | Ch | Shootable block |
5 | Horizontal extension | Dh | Vertical extension |
6 | Unused air | Eh | Grapple block |
7 | Bombable air | Fh | Bombable block |
Block type | BTS | Description |
2 / Ah | Spike | 0 | Solid only. Generic spike (60 damage) |
1 | Solid only. Kraid's lair spike (10h damage) |
2 | Air only. Air spike (10h damage) |
3 | Solid only. Draygon's broken turret (10h damage) |
Fh | Solid only. Enemy breakable block (used in Shaktool's room) |
3 / Bh | Special | 0 | 1×1 respawning crumble block |
1 | 2×1 respawning crumble block |
2 | 1×2 respawning crumble block |
3 | 2×2 respawning crumble block |
4 | 1×1 crumble block |
5 | 2×1 crumble block |
6 | 1×2 crumble block |
7 | 2×2 crumble block |
8 | Air only. Rightwards treadmill, disabled in Wrecked Ship unless Phantoon is dead |
9 | Air only. Leftwards treadmill, disabled in Wrecked Ship unless Phantoon is dead |
Ah | Air only. Rightwards treadmill, always on |
Bh | Air only. Leftwards treadmill, always on |
Eh | Respawning speed boost block |
Fh | Speed boost block |
44h | Generic PLM shot trigger |
45h | Item collision detection |
46h | Scroll PLM trigger |
47h | Map station right access |
48h | Map station left access |
49h | Energy station right access |
4Ah | Energy station left access |
4Bh | Missile station right access |
4Ch | Missile station left access |
4Dh | Save station trigger |
Crateria/debug | 80h | Air only. Ice physics |
Brinstar | 80h | Floor plant |
81h | Ceiling plant |
82h | Respawning speed block, slower crumble animation |
83h | Speed block, slower crumble animation |
84h | Respawning speed block (used by dechora pit) |
85h | Speed boost block |
Norfair | 83h | Lower Norfair chozo hand trigger |
Wrecked Ship | 80h | Wrecked Ship chozo hand trigger |
Maridia | 80h | Quicksand surface, can run on without sinking (used in snail room) |
81h | Quicksand surface |
82h | Quicksand surface |
83h | Submerging quicksand (used in sand falls rooms) |
84h | Sand falls - slow. Used in the ceilings of pre-Draygon mochtroid rooms (so basically unused) |
85h | Sand falls - fast |
7 / Fh | Bombable | 0 | 1×1 respawning bomb block |
1 | 2×1 respawning bomb block |
2 | 1×2 respawning bomb block |
3 | 2×2 respawning bomb block |
4 | 1×1 bomb block |
5 | 2×1 bomb block |
6 | 1×2 bomb block |
7 | 2×2 bomb block |
4 / Ch | Shootable | 0 | 1×1 respawning shot block |
1 | 2×1 respawning shot block |
2 | 1×2 respawning shot block |
3 | 2×2 respawning shot block |
4 | 1×1 shot block |
5 | 2×1 shot block |
6 | 1×2 shot block |
7 | 2×2 shot block |
8 | Respawning power bomb block |
9 | Power bomb block |
Ah | Respawning super missile block |
Bh | Super missile block |
10h | Gate blocks |
40h | Blue door facing left |
41h | Blue door facing right |
42h | Blue door facing up |
43h | Blue door facing down |
44h | Generic shot trigger |
45h | Item trigger |
46h | Left blue gate trigger |
47h | Right blue gate trigger |
48h | Left red gate trigger |
49h | Right red gate trigger |
4Ah | Left green gate trigger |
4Bh | Right green gate trigger |
4Ch | Left orange gate trigger |
4Dh | Right orange gate trigger |
4Fh | Critters escape block |
FX
__________________________________________ Door pointer
| _____________________________________ Base Y position
| | ________________________________ Target Y position
| | | ___________________________ Y velocity
| | | | ______________________ Timer
| | | | | ___________________ Layer 3 type
| | | | | | ________________ Default layer blending configuration (FX A)
| | | | | | | _____________ FX layer 3 layer blending configuration (FX B)
| | | | | | | | __________ Liquid options (FX C)
| | | | | | | | | _______ Palette FX bitset
| | | | | | | | | | ____ Animated tiles bitset
| | | | | | | | | | | _ Palette blend
| | | | | | | | | | | |
dddd,bbbb,tttt,vvvv,tt,ff,AA,BB,CC,pp,aa,bb ; First FX entry
dddd,bbbb,tttt,vvvv,tt,ff,AA,BB,CC,pp,aa,bb ; Second FX entry
[...] ; Other FX entries
0000,bbbb,tttt,vvvv,tt,ff,AA,BB,CC,pp,aa,bb ; Default FX entry
OR
FFFF ; No FX
FX defines roomwide graphical effects, they're stored in bank $83.
A room either has a two byte FFFF
entry specifying there is no FX, or it has optional door-dependent FX entries followed by the default entry.
A door-dependent FX entries is used if the door taken into the room matches the entry's door pointer, if no doors match (or if there are no entries) the default entry is used.
0 | None |
2 | Lava |
4 | Acid |
6 | Water |
8 | Spores |
Ah | Rain |
Ch | Fog |
20h | Scrolling sky |
22h | Unused |
24h | Fireflea |
26h | Tourian entrance statue |
28h | Ceres Ridley |
2Ah | Ceres elevator |
2Ch | Haze |
Layer blending configurations
Layer blending configurations
2/Eh/20h | Normal. BG1/BG2/sprites are drawn with BG3 added on top | |
4 | Normal, but BG2 is disabled | Used by Phantoon |
6 | Normal, but sprites aren't affected by BG3 and sprites are added to BG1/BG2 (instead of hidden) | Unused |
8 | Normal, but BG1/sprites aren't affected by BG3 and sprites are added to BG2 (instead of hidden) | Used in some power off Wrecked Ship rooms |
Ah | Normal, but BG1 isn't affected by BG3 | Used with FX layer 3 type = spores |
Ch | Normal, but BG3 is disabled and colour math is subtractive | Used with FX layer 3 type = fireflea |
10h/12h | Normal, but BG3 is disabled inside window 1 | Used by morph ball eye and varia/gravity suit pickup |
14h/22h | Normal, but BG1 isn't affected by BG3 and colour math is subtractive | Sometimes use with FX layer 3 type = water |
16h | BG1/sprites are drawn after the result of drawing BG2/BG3 is subtracted | Sometimes use with FX layer 3 type = water |
18h/1Eh/30h | BG3 is drawn with the result of drawing BG1/BG2/sprites added on top | Used with FX layer 3 type = lava / acid / fog / Tourian entrance statue, sometimes use with FX layer 3 type = water |
1Ah | Normal, but BG2 and BG3 have reversed roles | Used by Phantoon |
1Ch | Normal, but BG2 and BG3 have reversed roles, colour addition is halved and backdrop is disabled | Unused |
24h | BG1/BG2/sprites are drawn the backdrop is added on top inside window 1 | Used by Mother Brain |
26h | Normal, but colour addition is halved | Unused |
28h | Normal, but BG3 is disabled, colour math is subtractive, and the backdrop subtracts red if there is no power bomb explosion | Used in some default state Crateria rooms, some power off Wrecked Ship rooms, pre plasma beam rooms |
2Ah | Normal, but BG3 is disabled, colour math is subtractive, and the backdrop subtracts orange if there is no power bomb explosion | Used in blue Brinstar rooms, Kraid's lair entrance, n00b tube side rooms, plasma beam room, some sand falls rooms |
2Ch | Normal, but BG3 is disabled | Used by FX layer 3 type = haze and torizos |
2Eh | Normal, but colour math is subtractive | Unused |
32h | Normal, but BG1 isn't affected by BG3 and colour math is subtractive | Unused |
34h | Normal, but power bombs don't affect BG2 | Unused |
1 | Liquid flows (leftwards) |
2 | Layer 2 is wavy |
4 | Liquid physics are disabled (used in n00b tube room) |
40h | Big tide (liquid fluctuates up and down, a la the gauntlet) |
80h | Small tide (liquid fluctuates up and down) |
Enemy population
____________________________________ Enemy ID
| _______________________________ X position
| | __________________________ Y position
| | | _____________________ Initialisation parameter (orientation in SMILE)
| | | | ________________ Properties (special in SMILE)
| | | | | ___________ Extra properties (special graphics bitset in SMILE)
| | | | | | ______ General purpose parameter (speed in SMILE)
| | | | | | | _ General purpose parameter (speed2 in SMILE)
| | | | | | | |
iiii xxxx yyyy oooo pppp gggg aaaa bbbb ; First enemy
iiii xxxx yyyy oooo pppp gggg aaaa bbbb ; Second enemy
[...] ; Other enemies
FFFF ; Terminator
nnnn ; Number of enemy deaths needed to clear current room
Enemy population defines the placement of enemies, as well as some generic and enemy specific properties, they're stored in bank $A1 with each enemy being 16 bytes, plus a 4 byte overhead.
The initialisation parameter is overwritten by generic enemy routines and so is often only used during enemy initialisation, the other two general purpose parameters do not have this restriction.
The properties are as follows:
8000h | Hitbox solid to Samus |
4000h | Respawns if killed |
2000h | Process instructions |
1000h | Block plasma beam |
800h | Process whilst off-screen |
400h | Intangible |
200h | Delete |
100h | Invisible |
The extra properties are as follows:
4 | Enable extended spritemap format |
1 | Disable enemy AI. Isn't disabled if intangible |
Enemy set
______ Enemy ID
| _ Palette index
| |
iiii pppp ; First enemy
iiii pppp ; Second enemy
[...] ; Other enemies
FFFF ; Terminator
_______ First scroll
| ____ Second scroll
| | _ Other scrolls
| | |
aa bb [...]
Special x-ray blocks
_______ X position
| ____ Y position
| | _ Block number
| | |
xx yy nnnn ; First x-ray block
xx yy nnnn ; Second x-ray block
[...] ; Other x-ray blocks
0000 ; Terminator
PLM population
____________ PLM ID
| _______ X position
| | ____ Y position
| | | _ Parameter
| | | |
iiii xx yy pppp ; First PLM
iiii xx yy pppp ; Second PLM
[...] ; Other PLMs
0000 ; Terminator
Library background
______ Type
| _ Parameters
| |
tttt [...] ; First background command
tttt [...] ; Second background command
[...] ; Other background commands
0000 ; Terminator
The list of commands used in Super Metroid is as follows:
Type | Parameters | Description |
2 | ssssss dddd nnnn | Transfer n bytes from s to d in VRAM |
4 | ssssss dddd | Decompress s to d in bank $7E |
6 | | Clear layer 3 |
8 | ssssss dddd nnnn | Transfer n bytes from s to d in VRAM and set BG3 tiles base address = $2000 |
Ah | | Clear layer 2 |
Ch | | Clear Kraid's layer 2 |
Eh | DDDD ssssss dddd nnnn | Transfer n bytes from s to d in VRAM if the current door pointer = D |