F-Zero RAM Map

Here is a RAM Map for F-Zero that aims to be fairly comprehensible.

Data Types

Name	Accepted Values	Size	Description
Angle16	0x0000 - 0xBFFF	16-bit	An angle with extra fractional precision. 0x0000 = 0 degrees 0xBFFF ≃ 359.992675781 degrees Only the high byte affects the gameplay, the low byte is there just for fractional precision. (Each unit increments the real angle value by about 0.00732421875 degrees)
Angle8	0x00 - 0xBF	8-bit	An angle without the fractional precision. 0x00 = 0 degrees 0xBF ≃ 358.125 degrees (Each unit increments the real angle value by about 1.875 degrees)
CoordX	0x0000 - 0x1FFF	16-bit	X coordinate value.
CoordY	0x0000 - 0x0FFF	16-bit	Y coordinate value.

Zero Page (Direct Page)

The Direct Page register (DP) is fixed to #$0000 all the time.

Address	Length	Type	Description
$7E0000	?? bytes	Misc.	Scratchpad RAM. Used for various purposes, including: temporary storage, subroutine parameters, etc.
$7E0034	1 byte	Sprites	Used in the AI car graphics routine. How many sprite tiles were needed to draw the AI car. Stored to $7E11D0 when the graphics routine ends.
$7E003E	2 bytes	Misc.	Relevant value picked from the table at 7E:1076.
$7E0040	1 byte	Flag	"Frame done" flag. Set to zero at the start of the main loop. When NMI happens, it's decremented to #$FF, unless the value was already non-zero (i.e. a lag frame occurred.) This is used to make sure the gamestate runs once per frame.
$7E0041	2 bytes	Pointer	IRQ code pointer. $8612 - Do nothing; $8616 (V-Counter = 18) - Set transparent power bar color, then trigger next IRQ at V-Counter = 28, set IRQ code pointer $863C; $863C (V-Counter = 28) - Set "horizon fog" color math settings, then trigger next IRQ at V-Counter = 47, set IRQ code pointer $865A; $865A (V-Counter = 47) - Set BG mode to 7, then trigger next IRQ at V-Counter = 86, set IRQ code pointer $8673; $8673 (V-Counter = 86) - Set player's shadow/finished rank color, then set the IRQ code pointer to $8612; $8691 (V-Counter = $7E0043) - Set BG mode to 7, then set the IRQ code pointer to $8612.
$7E0043	2 bytes	IRQ	Scanline where the Mode7 BG starts. Used only for IRQ pointer $8691, on the race intro sequence.
$7E0045	1 byte	Flag	When the MSB is set, sound effects won't play. This is used to keep playing the "player wreckage" sounds when $7E0048 >= #$80.
$7E0046	4 bytes	I/O	SPC700 I/O ports. Various values can be written to play music or sound effects.
$7E004A	1 byte	Misc.	Number of cars currently on screen, multiplied by two. (A bit of a mystery still, but seems to be used in a loop that assigns sprite properties based on their Y position)
$7E004B	2 bytes	Sprites	Index to OAM Table #1 ($7E0200) for routines that print characters/strings on screen.
$7E004D	1 byte	Sprites	Index to OAM Table #2 ($7E0420) for routines that print characters/strings on screen.
$7E004E	1 byte	Sprites	Used for bit-fiddling on OAM Table #2. Used in conjunction with $7E004D.
$7E004F	1 byte	Hardware mirror	Mirror of SNES register $2101.
$7E0050	1 byte	Flag	"Is the game drawing cars" flag. Non-zero = Yes. This is used to correctly handle OAM DMA.
$7E0051	1 byte	Counter	Frame counter. Always increments every frame (except lag frames), no matter what. See also: $7E009A ("in-race" frame counter)
$7E0052	1 byte	Misc.	Player car type. #$00 = Blue Falcon; #$01 = Wild Goose; #$02 = Golden Fox; #$03 = Fire Stingray.
$7E0053	1 byte	Misc.	Current race number. From #$00 to #$04 in Grand Prix mode. From #$00 to #$06 in Practice mode.
$7E0054	3 bytes	Misc.	Current gamestate (game mode). The first byte is the "main" gamestate, the second byte is the "sub" gamestate and the third byte is the "sub-sub" gamestate. This gamestate stuff is a complicated subject, which I plan to explain in more detail later.
$7E0057	1 byte	Misc.	Current difficulty setting. #$00 = Beginner; #$01 = Standard; #$02 = Expert/Master (for Master, the flag at $7E0F3D is set)
$7E0058	1 byte	Misc.	Practice mode flag. #$00 = Grand Prix mode; #$01 = Practice Mode
$7E0059	1 byte	Misc.	Number of spare machines (extra lives).
$7E005A	1 byte	Misc.	Used by most menus as current selected option.
$7E005B	1 byte	Misc.	"Is running pre-recorded race" flag. #$00 = Player is in control; Other = Pre-recorded race is running.
$7E005C	1 byte	Flag	A flag related to color math effects. When == #$00: HDMA channels 1 and 3 are disabled; $7E009B is stored to $2131; $7E0E27 is treated as the red color intensity for color math and it should range from #$00 to #$1F. ($7E0E27 | #$20) is stored to $2132; 7E:0E28 is treated as the green color intensity for color math and it should range from #$00 to #$1F. ($7E0E28 | #$40) is stored to $2132; 7E:0E29 is treated as the blue color intensity for color math and it should range from #$00 to #$1F. ($7E0E29 | #$80) is stored to $2132; IRQ is disabled. When == #$01: HDMA channels 1 and 3 are enabled. Channel 1 is used for Mode7 and BG1 horizon, channel 3 is used for the "horizon fog"; $212C is set to (#$13 ^ $7E005F); $7E0E25 is stored to $2131; $2132 is set to #$E0; IRQ is enabled to trigger at V-Counter = 18, IRQ code pointer is set to $8616. When > #$01: HDMA channel 1 is enabled. Channel 1 is used for Mode7 and BG1 horizon; HDMA channel 3 is disabled; $212C is set to #$13; IRQ is enabled to trigger at V-Counter = $7E0043, IRQ code pointer is set to $8691.
$7E005D	1 byte	Hardware mirror	Screen brightness and F-Blank flag. Mirror of SNES register $2100
$7E005E	1 byte	Hardware mirror	Enabled HDMA channels. Mirror of SNES register $420C
$7E005F	1 byte	Flag	Flags related to shown layers and HUD updating. Format: u--s4321 1 = Hide BG1; 2 = Hide BG2; 3 = Show BG3; 4 = Hide BG4 (unused, F-Zero never uses BG4); s = Hide sprites; - = Unused bit u = Stop updating HUD (rank, timer, score and speedometer)
$7E0060	1 byte	Misc.	Screen fade type. #$00 = Not fading; #$01 = Fade-in; Other = Fade-out.
$7E0061	1 byte	Misc.	Screen fade delay. How many frames it takes to increment/decrement the screen brightness.
$7E0062	1 byte	Misc.	Screen fade timer. How many frames until the screen brightness is incremented/decremented.
$7E0063	1 byte	I/O	Controller 1 data (held buttons). Format: axlr---- a = A; x = X; l = L; r = R; - = Unused bits
$7E0064	1 byte	I/O	Controller 1 data (held buttons). Format: byetUDLR b = B; y = Y; e = Select; t = Start; U = Up; D = Down; L = Left; R = Right.
$7E0065	1 byte	I/O	(Seems to be the exact same as $7E0063?) Used more often than $7E0063
$7E0066	1 byte	I/O	(Seems to be the exact same as $7E0064?) Used more often than $7E0064
$7E0067	1 byte	I/O	Controller 1 data (pressed buttons on current frame). Format: axlr---- a = A; x = X; l = L; r = R; - = Unused bits
$7E0068	1 byte	I/O	Controller 1 data (pressed buttons on current frame). Format: byetUDLR b = B; y = Y; e = Select; t = Start; U = Up; D = Down; L = Left; R = Right.
$7E0069	1 byte	I/O	Controller 1 data (released buttons on current frame). Format: axlr---- a = A; x = X; l = L; r = R; - = Unused bits
$7E006A	1 byte	I/O	Controller 1 data (released buttons on current frame). Format: byetUDLR b = B; y = Y; e = Select; t = Start; U = Up; D = Down; L = Left; R = Right.
$7E006B	1 byte	Flag	A flag related to windowing effects. When == #$00: $212E and $212F are set to #$00; $7E0070 is stored to $2130; HDMA channel 2 is disabled. When == #$01: HDMA channel 2 is enabled. Channel 2 is used for windowing effects, such as player's shadow and the big rank number when finishing a race; $7E006C is stored to $4322 (16-bit, HDMA channel 2 table address); $7E0E20 is stored to $7E0DE3; $7E006E is stored to $212E; $7E006F is stored to $212F; $7E0070 is stored to $2130; $7E0071 is stored to $2123; $7E0072 is stored to $2124; $7E0073 is stored to $2125. When > #$01: $7E006E is stored to $212E; $7E006F is stored to $212F; $7E0070 is stored to $2130; $7E0071 is stored to $2123; $7E0072 is stored to $2124; $7E0073 is stored to $2125.
$7E006C	2 bytes	Pointer	Pointer to data for windowing effects (HDMA channel 2). Points to $7E0DD0 while racing, and to $7E0DF0 while showing the big rank number after finishing a race.
$7E006E	1 byte	Hardware mirror	Mirror of SNES register $212E.
$7E006F	1 byte	Hardware mirror	Mirror of SNES register $212F.
$7E0070	1 byte	Hardware mirror	Mirror of SNES register $2130.
$7E0071	1 byte	Hardware mirror	Mirror of SNES register $2123.
$7E0072	1 byte	Hardware mirror	Mirror of SNES register $2124.
$7E0073	1 byte	Hardware mirror	Mirror of SNES register $2125.
$7E0074	1 byte	Misc.	Index to $7E0EA0. Alternates between #$00 and #$10 every frame, to compensate for slowdowns (if it didn't alternate, the Mode7 layer would look jiterry when updating while the game was lagging).
$7E0075	2 bytes	Hardware mirror	BG1 horizontal scroll. Mirror of SNES register $210D.
$7E0077	2 bytes	Hardware mirror	BG1 vertical scroll. Mirror of SNES register $210E.
$7E0079	2 bytes	Hardware mirror	BG2 horizontal scroll. Mirror of SNES register $210F.
$7E007B	2 bytes	Hardware mirror	BG2 vertical scroll. Mirror of SNES register $2110.
$7E007D	2 bytes	Hardware mirror	Mode7 X center. Mirror of SNES register $211F.
$7E007F	2 bytes	Hardware mirror	Mode7 Y center. Mirror of SNES register $2120.
$7E0081	1 byte	Misc.	Mode7 rendering type. #$00 = No Mode7; #$01 = Perspective effect; Other = Top-down view.
$7E0082	1 byte	Misc.	This value + #$80 is written to $4342 and $4372. Similarly, this value + #$A0 is written to $4352 and $4362. This updates the Mode 7 rotation through HDMA. Similar to $7E0074, this address also alternates between #$00 and #$10 every frame to compensate for slowdowns. Only used if $7E0081 == #$01.
$7E0083	1 byte	Misc.	Used after the "track zoom-in" on the race intro. This value is incremented every frame to raise the viewpoint pitch angle. When it reaches #$10, it stops increasing and the cars appear.
$7E0084	1 byte	Hardware mirror	Written to $4347. Only used if 7E:0081 == #$01.
$7E0085	1 byte	Hardware mirror	Written to $4357. Only used if 7E:0081 == #$01.
$7E0086	1 byte	Hardware mirror	Written to $4367. Only used if 7E:0081 == #$01.
$7E0087	1 byte	Hardware mirror	Written to $4377. Only used if 7E:0081 == #$01.
$7E0088	2 bytes	Hardware mirror	Mode7 matrix A and D. Mirror of SNES registers $211B and $211E
$7E008A	2 bytes	Hardware mirror	Mode7 matrix B. Mirror of SNES register $211C
$7E008C	2 bytes	Hardware mirror	Mode7 matrix C. Mirror of SNES register $211D
$7E008E	2 bytes	Misc.	Mode7 scaling. The Mode7 layer shrinks as this value increases. Only used if $7E0081 > #$01 (top-down view)
$7E0090	1 byte	Misc.	Current league. #$00 = Knight League; #$01 = Queen League; #$02 = King League.
$7E0091	1 byte	Empty	Empty. Cleared on reset

This is still a work-in-progress! More will be added later.