Debug mode

The Debug Mode was a mode used by the developers to test out various features and to find bugs.

Classic Debug Display

This debug menu was one of the first found in-game with the use of a GameShark. It displays information on Mario's angle, speed, and action, as well as memory info.

Access

To enable the classic debug display, enter the appropriate Gameshark code for your version of the game.

Japan	USA	Europe	Japan (Shindou)
A032C658 0059	A032D598 0059	A02F9748 0059	A030CCC8 0059

Items

Label	Meaning	Description
ANG	Angle	ANG is the slope of the ground in degrees (0 = flat, 90 = vertical)
SPD	Speed	SPD is Mario’s forward velocity.
STA	State	STA is the last 9 bits of Mario’s state variable.
MEM	Memory	Current RAM usage.
BUF	Buffer	BUF is how many bytes are left in the draw buffer. Display lists and transformation matrices are allocated and freed every frame.

Complex Debug Display

This more comprehensive debug display depicts everything from map information to the current number of loaded objects. There also an unused function in the game’s code that toggles between the two debug modes when you enter a button sequence on the D-pad: Up up down down left right left right toggles a profiler Down down up up left right left right toggles some variable displays, dubbed ‘classic debug’

Access

File:SM64Debug2.png

To enable the complex debug display, enter the appropriate Gameshark code for your version of the game.

Japan	USA	Europe	Japan (Shindou)
8033BEF3 0001 D0339C30 0008 8032FF34 0001 D0339C30 0001 8032FF34 0002 D0339C30 0004 8032FF34 0003 D0339C30 0002 8032FF34 0004 D0339C31 0020 8032FF34 0005	8033D263 0001 D033AFA0 0008 80330E94 0001 D033AFA0 0001 80330E94 0002 D033AFA0 0004 80330E94 0003 D033AFA0 0002 80330E94 0004 D033AFA1 0020 80330E94 0005	8030AE93 0001 D0309260 0008 802FD054 0001 D0309260 0001 802FD054 0002 D0309260 0004 802FD054 0003 D0309260 0002 802FD054 0004 D0309261 0020 802FD054 0005	8031F423 0001 D031D560 0008 803105C4 0001 D031D560 0001 803105C4 0002 D031D560 0004 803105C4 0003 D031D560 0002 803105C4 0004 D031D561 0020 803105C4 0005

Options

D-Right - Map Info

Press D-Right to display the "MAPINFO" screen.

Option	Meaning	Description	Notes
AREA	Area	What cell of the collision grid Mario is in.
WX	World X	Mario's current X coordinate.
WY	World Y	Mario's current Y coordinate.
WZ	World Z	Mario's current Z coordinate.
BGY	Boundary Ground Y	Y coordinate of the ground below Mario.
ANGY	Angle Y	Y angle of the ground below Mario.
BGCODE	Boundary Ground Code	Type of the triangle below Mario.	Terrain types can denote slipperiness, camera mode, special properties (sand, snow, wind, water flow), special triangles (painting entrances)
BGSTATUS	Boundary Ground Status	Status bits of the triangle below Mario.	1 means the triangle is part of an object, 2 means the camera won't collide with this triangle. 3 means both apply.
BGAREA	Boundary Ground Area	Which room the floor triangle belongs to.	In the castle, Hazy Maze Cave and Big Boo's haunt the area is split up into rooms which are defined by this property of triangles.
DPRINT OVER	Debug Print Overflow	Appears when text doesn't fit on the screen anymore.
WATER	Water level	Y coordinate of the surface of the water if Mario is standing or swimming in it	Only appears when you ensure DPRINT OVER doesn't happen
OBJ	Objects	Number of objects currently loaded.	Only appears when you ensure DPRINT OVER doesn't happen

D-Down - Stage Info

Press D-Down to display the "STAGEINFO" screen.

Option	Meaning	Description	Notes
STAGE PARAM	Stage Parameter	At what time you entered Tick-Tock Clock.	0 means that the long hand was pointing to 3, resulting in slow time; 1 means that the long hand was pointing to 9, resulting in fast time; 2 means that the long hand was pointing to 6, resulting in things moving at random; 3 means that the long hand was pointing to 12, resulting in a still stage.
OBJ	Objects	Number of objects currently loaded.

D-Left - Effect Info

Press D-Left to display the "EFFECTINFO" screen.

Option	Meaning	Description	Notes
A	?	Currently unknown.	Value does not seem to change.
A0	?	Currently unknown.	Value does not seem to change.
A1	?	Currently unknown.	Value does not seem to change.
A2	?	Currently unknown.	Value does not seem to change.
A3	?	Currently unknown.	Value does not seem to change.
A4	?	Currently unknown.	Value does not seem to change.
A5	?	Currently unknown.	Value does not seem to change.
A6	?	Currently unknown.	Value does not seem to change.
A7	?	Currently unknown.	Value does not seem to change.
OBJ	Objects	Number of objects currently loaded.

D-Up - Check Info

Press D-Up to display the "CHECKINFO" screen. This screen shows info related to collision checking.

Option	Meaning	Description	Notes
AREA	Area	What cell of the collision grid Mario is in.
DG	Data Ground?	Amount of floor triangle checks / such triangles in Mario's area.	Two columns
DW	Data Wall?	Amount of wall triangle checks / such triangles in Mario's area.
DR	Data Roof?	Amount of ceiling triangle checks / such triangles in Mario's area.
LISTAL	List Area Length?	Amount of triangle nodes loaded.
STATBG	Static Boundraries	Amount of level triangles loaded.
MOVEBG	Moving Boundraries	Amount of object triangles loaded.
NULLBG	Null Background	How often a floor-check couldn't find a triangle this frame.
OBJ	Objects	Number of objects currently loaded.

L - Enemy Info

Press L to display the "ENEMYINFO" screen.

Option	Meaning	Description	Notes
B	?	Currently unknown.	Value does not seem to change.
B0	?	Currently unknown.	Value does not seem to change.
B1	?	Currently unknown.	Value does not seem to change.
B2	?	Currently unknown.	Value does not seem to change.
B3	?	Currently unknown.	Value does not seem to change.
B4	?	Currently unknown.	Value does not seem to change.
B5	?	Currently unknown.	Value does not seem to change.
B6	?	Currently unknown.	Value does not seem to change.
B7	?	Currently unknown.	Value does not seem to change.
OBJ	Objects	Number of objects currently loaded.

Debug Resource Meter

The profiler shows how well the game can maintain its frame rate of 30 fps.

There are four colored bars acting as a timescale on the bottom. Each bar represents 1/60th of a second. On top of it, the time of the audio thread (red), game logic thread (yellow) and video thread (orange) are plotted. When the top bars reach the orange reference bar, it means they took more than 1/30th of a second so a lag frame is introduced. A little red bar is drawn in the middle left when that occurs. When it reaches red, two lag frames are introduced. During room transitions, tens of lag frames are introduced because loading takes several frames. The profiler will spike for a frame then. When you press L, the bars are shown in a different way. The time bars are moved to the right, and on top of the blue bar, a yellow bar is now drawn. It seems like in this view, the red, yellow and orange times are not grouped. It rather shows a timeline of which thread is active.

This profiler also exists in Mario Kart 64.

Japan	USA	Europe	Japan (Shindou)
8032C654 0001	8032D594 0001	802F9744 0001	8030CCC4 0001

Debug Spawn

This function causes various objects to spawn that alter Mario's movement. Press the D-Pad buttons to spawn either nothing, a normal Koopa Shell, a water Koopa Shell, or a Crazy Box. Don't try to use it inside the castle, though, or the game might crash.

Japan	USA	Europe	Japan (Shindou)
8032FF34 0003 8133BF6E 0001	80330E94 0003 8133D2DE 0001	802FD054 0003 8130AF0E 0001	803105C4 0003 8131F49E 0001

Free Movement Mode

This function enables a free-movement mode that lets Mario zoom about freely. There is collision checking with walls and floors, but not with ceilings. When you hold B, you move with 128 units per frame, and walls are 100 units thick so you can pass through them. No quarter frame checks are done in this mode.

Controls:

• Joystick: Moves Mario laterally with 32 units per frame.
• D-Pad: Moves Mario up or down with 16 units per frame
• Hold B: These speeds are multiplied by 4.
• Hold L: Multiplies the speed by 0.01, giving very slow and precise movement.
• A: Make Mario exit to an in-air or underwater state.

Japan	USA	Europe	Japan (Shindou)
D1339C30 2100 8126976E 5F0D D1339C30 8000 8126976E 97D1	D133AFA0 2100 81269BDA 5FAB D133AFA0 8000 81269BDA 98D5

Level Select

Access

Japan	USA	Europe	Japan (Shindou)
A032C64C 0001	A032D58C 0001	A02F973C 0001	A030CCBC 0001

Options

File:SM64LevelSelect.png

This level select features an early version of the title screen. When enabled, it replaces the file select screen. The courses are listed in the order that their data appears in the game's memory.

When a level is selected, Mario will automatically be sent to the first Star, bypassing the Star selection screen. Exiting a course via Star collection, death, or the pause menu will bring you back to the level select screen. Attempting to access one of the removed entries causes the game to reset.

Controls:

• A: Scroll forward by 1.
• B: Scroll backward by 1.
• D-Up: Scroll forward by 1.
• D-Down: Scroll backward by 1.
• D-Right: Scroll forward by 10.
• D-Left: Scroll backward by 10.
• Start: Enter level.
• Z + C-Left + C-right + Start: Reboot game without level select

Level Select Name	Literal Translation	Final Location
1	1:	[Removed]
2	2:	[Removed]
3	3:	[Removed]
4 TERESA OBAKE	4: Boo Apparition	Big Boo's Haunt
5 YYAMA1 % YSLD1	5: Snow Mountain 1 & Snow Slide 1	Cool, Cool Mountain
6 SELECT ROOM	6: Select Room	Inside Peach's Castle
7 HORROR DUNGEON	7: Horror Dungeon	Hazy Maze Cave
8 SABAKU % PYRMD	8: Desert & Pyramid	Shifting Sand Land
9 BATTLE FIELD	9: Battlefield	Bob-omb Battlefield
10 YUKIYAMA2	10: Snow Mountain 2	Snowman's Land
11 POOL KAI	11: Pool Stage	Wet-Dry World
12 WTDG % TINBOUTU	12: Water Dungeon & Submersion	Jolly Roger Bay
13 BIG WORLD	13: Big World	Tiny-Huge Island
14 CLOCK TOWER	14: Clock Tower	Tick Tock Clock
15 RAINBOW CRUISE	15: Rainbow Cruise	Rainbow Ride
16 MAIN MAP	16: Main Map	Outside the Castle
17 EXT1 YOKO SCRL	17: Bonus 1 - Side-Scroller	Bowser in the Dark World
18 EXT7 HORI MINI	18: Bonus 7 - Moat (Mini)	Vanish Cap Under the Moat
19 EXT2 TIKA LAVA	19: Bonus 2 - Basement Lava	Bowser in the Fire Sea
20 EXT9 SUISOU	20: Bonus 9 - Fish Tank	The Secret Aquarium
21 EXT3 HEAVEN	21: Bonus 3 - Heaven	Bowser in the Sky
22 FIREB1 % INVLC	22: Fire Bubble & In the Volcano	Lethal Lava Land
23 WATER LAND	23: Water Land	Dire, Dire Docks
24 MOUNTAIN	24: Mountain	Whomp's Fortress
25 ENDING	25: Ending	"The End" Image
26 URANIWA	26: Back Garden	Castle Courtyard
27 EXT4 MINI SLID	27: Bonus 4 - Mini Slide	The Princess's Secret Slide
28 IN THE FALL	28: In the Fall	Cavern of the Metal Cap
29 EXT6 MARIO FLY	29: Bonus 6 - Mario Fly	Tower of the Wing Cap
30 KUPPA1	30: Bowser 1	Bowser in the Dark World (Boss)
31 EXT8 BLUE SKY	31: Bonus 8 - Blue Sky	Wing Mario Over the Rainbow
32	32:	[Removed]
33 KUPPA2	33: Bowser 2	Bowser in the Fire Sea (Boss)
34 KUPPA3	34: Bowser 3	Bowser in the Sky (Boss)
35	35:	[Removed]
36 DONKEY % SLID2	36: Monkey & Slide 2	Tall Tall Mountain
37	37:	[Removed]
38	38:	[Removed]

With this flag on, you also won’t lose health from being underwater water, in cold water, or in toxic haze. This is not a side-effect, but explicitly programmed in.

For some reason, if Peach's Castle is entered via the level select, no background music will play there.

While bonus levels marked "EXT1" to "EXT9" are present (standing for "extra"), "EXT5" is missing. It may have been removed during development, or it may be that the label is simply missing from the entry for Cavern of the Metal Cap.

The use of "Donkey" for "Monkey" is possibly a tongue-in-cheek reference to Donkey Kong.

Frame advance

The short at 0x339EC8 is 0 normally and 2 when the game is paused, 4 during transitions (entering a painting, going through a door, debug level select). When you hack it to 5 you enter a frame advance mode.

The game then only advances a frame if you press D-pad down.

Debug Print

While the ‘classic display’ shows some variable on a fixed position, there is also a whole system for automatically laying out debug text. The state is stored in a struct:

   typedef struct 
   {
   	short disabled,	//0x00	(if not zero, it doesn't draw)
   	short cursor_x,	//0x02
   	short cursor_y,	//0x04
   	short min_y,		//0x06 causes DPRINT OVERFLOW if cursor_y not 
   	short max_y,		//0x08 in this range
   	short line_y_offset, 	//0x0A equals -15 (top aligned) or +15 (bottom aligned)
   } DprintState;

There are two of these states, one in the top left corner growing down, and one in the bottom right corner growing up. Note that (0, 0) is the bottom left corner and (320, 240) is the top right corner. Now whenever the developers wanted to show a certain variable, they would call a function that automatically ensures it doesn’t overlap with other variables.

The bottom right corner is used for all kind of ad-hoc things, while in the top right there are 6 pages that you can scroll through.

Hold L and press C-up, left, down, right to toggle this menu on or off Hold L and press D-pad left to increase the page number and D-pad right to decrease it Press Z to toggle whether the text is collapsed

Things that appear in the Bottom right corner

NULLBG

Every time a floor check returns a null pointer a counter is incremented, and if it is positive it will be drawn with the label NULLBG. In the image, Mario’s four quarter steps are Out of Bounds so the counter is 4.

In some courses, you’ll see NULLBG in the corner whenever an object spawns. That’s because these objects aren’t in the right position right from the start: on the first frame, they are at (0, 0, 0). So if you’re in a stage where this origin point is not above a floor, NULLBG shows up whenever an object spawns.

Similar to NULLBG, there is a WALL counter. It only pop-ups when the wall counter is higher than 0, but that never happens. The counter gets reset to 0 every frame, but nowhere does it get incremented.

SL Penguin

In Snowman’s Land, the X and Z coordinates of the penguin are shown. (The NULLBG in the image is because the snowman’s wind particles spawn on the origin, which is Out of Bounds in Snowman’s Land)

Break free of Chuckya

When Mario is grabbed by King Bob-omb / Chuckya, a number appears signifying how many times you pressed A or jolted the control stick. When it reaches 11, you break free. The developers probably displayed this to gauge what a reasonable button mashing rate is for breaking free.

==If you're reading this, remind Thestickman391 to finish this page