Mega Man 2/ROM map: Difference between revisions

Latest revision as of 14:27, 24 January 2024

The following article is a ROM map for Mega Man 2.

Gameplay Data

Mega Man

Address	Function	Details	Default value
`0x03891F`	Mega Man's standstill x-velocity (integer)		`00`
`0x038920`	Mega Man's inching x-velocity (integer)		`00`
`0x038921`	Mega Man's walking x-velocity (integer)		`01`
`0x038922`	Mega Man's jumping x-velocity (integer)		`01`
`0x038923`	Mega Man's slip x-velocity (integer)		`00`
`0x038924`	Mega Man's landing x-velocity (integer)		`00`
`0x03892A`	Mega Man's standstill x-velocity (fraction)		`00`
`0x03892B`	Mega Man's inching x-velocity (fraction)		`20`
`0x03892C`	Mega Man's walking x-velocity (fraction)		`60`
`0x03892D`	Mega Man's jumping x-velocity (fraction)		`50`
`0x03892E`	Mega Man's slip x-velocity (fraction)		`80`
`0x03892F`	Mega Man's landing x-velocity (fraction)		`00`
`0x038A81`	Mega Man's jump height		`04`
`0x03D312` `-` `0x03D341` (USA), `0x03D30F` `-` `0x03D33E` (JPN)	Mega Man's palette for each weapon	Same order as pause menu	(Check respective weapons)

Heads-Up Display

Address	Function	Details	Default value
`0x02C142`	How fast the robot masters' health fills up		`03`
`0x02E12B`	How fast the fortress bosses' health fills up		`03`
`0x0352B2`	How fast Mega Man's health fills up while paused		`03`
`0x038315`	Maximum Energy for Mega Man		1C
`0x03831B`	How fast Mega Man's health fills up in-game		`07`
`0x03835A`	How fast Mega Man's weapon energy fills up in-game		`07`
`0x03CF79`	X position for energy bar		`18`
`0x03CF8F`	X position for weapon bar		`10`
`0x03CFB1`	X position for boss bar		`28`
`0x03CFD8`	Graphics for Energy Bar	This defines the leftmost tile (full HP graphic) and automatically picks to the right of it the remaining 4 tiles in descending order of HP, ex. `87`>`8B`, `DB`>`DF`.	`87`
`0x03CFF5`	Y position for 1/7 energy		`18`
`0x03CFF6`	Y position for 2/7 energy		`20`
`0x03CFF7`	Y position for 3/7 energy		`28`
`0x03CFF8`	Y position for 4/7 energy		`30`
`0x03CFF9`	Y position for 5/7 energy		`38`
`0x03CFFA`	Y position for 6/7 energy		`40`
`0x03CFFB`	Y position for 7/7 energy		`48`

READY Sprites

0x0381CC - 0x0381DF (0x14 = sprite data)
0x0381CC = Y position
0x0381CD = PPU Tile
0x0381CE = Palette, mirroring
0x0381CF = X position

format repeats

Sound Effects during Stage

Address	Function	Details	Default value
`0x03524E`	Changing selections in menu, Mega Man forming		`2F`
`0x0381E0` `-` `0x0381ED`	Music played for each level
`0x038685`	Sound for Mega Man landing		`29`
`0x03C59F`	Sound for entering menu screen during action		`32`
`0x03C802`	Sound effect for Mega Man beamed down		`30`

Pause Menu

Address	Function	Details	Default value
`0x0352AC`	The amount of energy that E-Tanks set		`1C`
`0x03539E`	Sound effect for turning off menu during action		`30`
`0x0353E8`	Starting Y position of the weapon icon sprites		`44`
`0x035403`	X position of the weapon icon sprites		`0C`
`0x03542C`	Y position of Mega Man's health bar		`44`
`0x03543D`	Y position of the first set of weapon energy bars		`54`
`0x03549C`	Y position of the second set of weapon energy bars		`44`
`0x03559E` `-` `0x03562D`	Pause menu tile layout

Arrow and NEXT Sprites

0x03563C - 0x03564F (0x14) = sprite data
0x03563C = Y position
0x03563D = PPU Tile
0x03563E = Palette, mirroring
0x03563F = X position

format repeats

Weapon Icon Sprites

0x035650 - 0x03565B (0xC) = sprite data
0x035650 = P / Mega Buster (Default: 1F)
0x035651 = H / Atomic Fire (Default: 9F)
0x035652 = A / Air Shooter (Default: 9B)
0x035653 = W / Leaf Shield (Default: 99)
0x035654 = B / Bubble Lead (Default: 9D)
0x035655 = Q / Quick Boomerang (Default: 9C)
0x035656 = F / Flash Stopper (Default: 9A)
0x035657 = M / Metal Blade (Default: 9E)
0x035658 = C / Crash Bomber (Default: 10)
0x035659 = 1 / Item 1 (Default: 15)
0x03565A = 2 / Item 2 (Default: 16)
0x03565B = 3 / Item 3 (Default: 17)

E-Tank Menu Sprite

0x03565C - 0x03565F (0x4) = sprite data
0x03565C = Y position
0x03565D = PPU Tile
0x03565E = Palette, mirroring
0x03565F = X position

Extra Life Menu Sprite

0x035660 - 0x03566F (0x10) = sprite data
0x035660 = Y position
0x035661 = PPU Tile
0x035662 = Palette, mirroring
0x035663 = X position

format repeats

Items

Address	Function	Details	Default value
`0x0380D5`	Beginning amount of Health		`1C`
`0x0382FD`	Amount of HP large Energy returns		`0A`
`0x038301`	Amount of HP small Energy returns		`02`
`0x03806C`	Amount of E-Tanks set after starting a new game		`00`
`0x038382`	Maximum amount of E-Tanks you can carry	Carrying anything higher than 4 E-Tanks will generate bad passwords.	`04`
`0x038390`	Maximum amount of lives you can carry	Due to how lives actually work, `00` is game over and `01` is actually 0 lives, so `63` would yield a 98 life limit instead of the usual 99.	`63`
`0x03C1CB`	Amount of E-Tanks set after continuing from a game over		`00`

Power Ups

Address	Function	Details	Default value
`0x03C289`	Power Up from Heat Man		`01`
`0x03C28A`	Power Up from Air Man		`02`
`0x03C28B`	Power Up from Wood Man		`04`
`0x03C28C`	Power Up from Bubble Man		`08`
`0x03C28D`	Power Up from Quick Man		`10`
`0x03C28E`	Power Up from Flash Man		`20`
`0x03C28F`	Power Up from Metal Man		`40`
`0x03C290`	Power Up from Crash Man		`80`
`0x03C291`	Item # from Heat Man		`01`
`0x03C292`	Item # from Air Man		`02`
`0x03C293`	Item # from Wood Man		`00`
`0x03C294`	Item # from Bubble Man		`00`
`0x03C295`	Item # from Quick Man		`00`
`0x03C296`	Item # from Flash Man		`04`
`0x03C297`	Item # from Metal Man		`00`
`0x03C298`	Item # from Crash Man		`00`

Screen Data

Stage Select

Address	Function	Details	Default value
`0x02EE10` `-` `0x02F1CF`	Stage select screen 8x8 tile placement
`0x02F1D0` `-` `0x02F20F`	Stage select screen 16x16 tile attribute
`0x0340D8`	Routine for checking if a level has been cleared
`0x0340EC` `-` `0x0340EF`	Routine for checking if a level has been cleared
`0x0340F6`	Confirming selection
`0x034186`	First override palette for Boss posing screen		`2C`
`0x03418B`	Second override palette for Boss posing screen		`11`
`0x0341BA`	Preview boss music		`0A`
`0x0342ED`	Selection for Bubble Man cursor
`0x0344A9` `-` `0x0344B8`	Palette background for Stage Select Screen
`0x0344B9` `-` `0x0344C8`	Palette foreground for Stage Select Screen
`0x034551` `-` `0x03460C`	Sprite table for Stage Select Screen (4 bytes per sprite)
`0x03460D` `-` `0x034614`	Starting index for mugshot group in sprite table	Order is Heat, Air, Wood, Bubble, Quick, Flash, Metal, Crash
`0x034615` `-` `0x03461C`	Number of bytes per mugshot group in sprite table	Order is Heat, Air, Wood, Bubble, Quick, Flash, Metal, Crash
`0x03462D`	Cursor Y position for Dr. Wily		`60`
`0x03462E`	Cursor Y position for Bubble Man		`20`
`0x03462F`	Cursor Y position for Air Man		`20`
`0x034630`	Cursor Y position for Quick Man		`20`
`0x034631`	Cursor Y position for Wood Man		`60`
`0x034632`	Cursor Y position for Crash Man		`A0`
`0x034633`	Cursor Y position for Flash Man		`A0`
`0x034634`	Cursor Y position for Metal Man		`A0`
`0x034635`	Cursor Y position for Heat Man		`60`
`0x034636`	Cursor X position for Dr. Wily		`70`
`0x034637`	Cursor X position for Bubble Man		`30`
`0x034638`	Cursor X position for Air Man		`70`
`0x034639`	Cursor X position for Quick Man		`B0`
`0x03463A`	Cursor X position for Wood Man		`B0`
`0x03463B`	Cursor X position for Crash Man		`B0`
`0x03463C`	Cursor X position for Flash Man		`70`
`0x03463D`	Cursor X position for Metal Man		`30`
`0x03463E`	Cursor X position for Heat Man		`30`
`0x03464F` `-` `0x034650`	Palette attribute data for Boss posing screen
`0x034651` `-` `0x03466E`	Lines for Boss posing screen data (reverse order)
`0x034670`	Pointer for Bubble Man Stage from selection
`0x034671`	Pointer for Air Man Stage from selection
`0x034672`	Pointer for Quick Man Stage from selection
`0x034673`	Pointer for Wood Man Stage from selection
`0x034674`	Pointer for Crash Man Stage from selection
`0x034675`	Pointer for Flash Man Stage from selection
`0x034676`	Pointer for Metal Man Stage from selection
`0x034677`	Pointer for Heat Man Stage from selection
`0x038076` `-` `0x03807D`	routine to see all weapons gained to go to Wily when selecting Start
`0x03C264` `-` `0x03C269`	routine to see all weapons gained to go to Wily after gaining a weapon

Wily Castle

Address	Function	Details	Default value
`0x0340E3`	First level of Wily's castle		`08`
`0x035994`	Path velocity in Wily's castle map		`03`
`0x035998`	Sound effect played when revealing a path tile		`28`

Wily Castle Dots

0x035D9C - 0x035DAF (0x14) = sprite data
0x035D9C = Y position
0x035D9D = PPU Tile
0x035D9E = Palette, mirroring
0x035D9F = X position

format repeats

Weapon Get Screens

Address	Function	Details	Default value
`0x037B95`	How long Megaman flashes while getting a weapon	00 isn't instantaneous, but 01 is	`9C`
`0x037C8C`	How long the screen flashes red before Dr. Light's message	00 isn't instantaneous, but 01 is	`7D`
`0x037D07`	How long Megaman flashes while getting an item	00 isn't instantaneous, but 01 is	`7D`
`0x037D4A`	How fast every letter gets revealed		`07`
`0x037DBC`	Length of pauses between Dr. Light's text boxes	00 isn't instantaneous, but 01 is	`7D`

Mega Man

0x0249FE - 0x024A8A (0x8D = Sprite data)
0x0249FF = Y position
0x024A00 = PPU Tile
0x024A01 = Palette, mirroring
0x024A02 = X position

format repeats

Dr. Light

0x024A8B - 0x024AD7 (0x4D = Sprite data)
0x024A8C = Y position
0x024A8D = PPU Tile
0x024A8E = Palette, mirroring
0x024A8F = X position

format repeats

Title

Address	Function	Details	Default value
`0x036235`	Sound effect for switching between Normal and Difficult on Title		`2F`
`0x0362D1`	Difficulty select arrow sprite tile		`A2`
`0x0362D2`	Palette, mirroring for arrow sprite		`01`
`0x0362D4`	X position for arrow		`30`
`0x0362D4`	Y position for arrow when selecting Normal		`98`
`0x0362D5`	Y position for arrow when selecting Difficult		`A8`
`0x036322`	Removes all power ups and $00FD
`0x03686D`	Sprite 1 for Title
`0x036877`	Sprite 2 for Title
`0x036AAF` `-` `0x036ABE`	Palette for sprites on Title
`0x036ACF` `-` `0x036ADE`	Palette background for Title
`0x037341`	Title Screen Last byte (reversed order)
`0x037700`	Title Screen First byte (reversed order)

Password

Sprites

0x036FD7 - 0x03700A (0x8D) = Sprite data
0x036FD7 = Y position
0x036FD8 = PPU Tile
0x036FD9 = Palette, mirroring
0x036FDA = X position

format repeats

Positions

Address	Function	Details	Default value
`0x03700B`	Password Y position (A,1)		`40`
`0x03700C`	Password Y position (A,2)		`40`
`0x03700D`	Password Y position (A,3)		`40`
`0x03700E`	Password Y position (A,4)		`40`
`0x03700F`	Password Y position (A,5)		`40`
`0x037010`	Password Y position (B,1)		`50`
`0x037011`	Password Y position (B,2)		`50`
`0x037012`	Password Y position (B,3)		`50`
`0x037013`	Password Y position (B,4)		`50`
`0x037014`	Password Y position (B,5)		`50`
`0x037015`	Password Y position (C,1)		`60`
`0x037016`	Password Y position (C,2)		`60`
`0x037017`	Password Y position (C,3)		`60`
`0x037018`	Password Y position (C,4)		`60`
`0x037019`	Password Y position (C,5)		`60`
`0x03701A`	Password Y position (D,1)		`70`
`0x03701B`	Password Y position (D,2)		`70`
`0x03701C`	Password Y position (D,3)		`70`
`0x03701D`	Password Y position (D,4)		`70`
`0x03701E`	Password Y position (D,5)		`70`
`0x03701F`	Password Y position (E,1)		`80`
`0x037020`	Password Y position (E,2)		`80`
`0x037021`	Password Y position (E,3)		`80`
`0x037022`	Password Y position (E,4)		`80`
`0x037023`	Password Y position (E,5)		`80`
`0x037024`	Password X position (A,1)		`41`
`0x037025`	Password X position (A,2)		`51`
`0x037026`	Password X position (A,3)		`61`
`0x037027`	Password X position (A,4)		`71`
`0x037028`	Password X position (A,5)		`81`
`0x037029`	Password X position (B,1)		`41`
`0x03702A`	Password X position (B,2)		`51`
`0x03702B`	Password X position (B,3)		`61`
`0x03702C`	Password X position (B,4)		`71`
`0x03702D`	Password X position (B,5)		`81`
`0x03702E`	Password X position (C,1)		`41`
`0x03702F`	Password X position (C,2)		`51`
`0x037030`	Password X position (C,3)		`61`
`0x037031`	Password X position (C,4)		`71`
`0x037032`	Password X position (C,5)		`81`
`0x037033`	Password X position (D,1)		`41`
`0x037034`	Password X position (D,2)		`51`
`0x037035`	Password X position (D,3)		`61`
`0x037036`	Password X position (D,4)		`71`
`0x037037`	Password X position (D,5)		`81`
`0x037038`	Password X position (E,1)		`41`
`0x037039`	Password X position (E,2)		`51`
`0x03703A`	Password X position (E,3)		`61`
`0x03703B`	Password X position (E,4)		`71`
`0x03703C`	Password X position (E,5)		`81`
`0x037056`	Password related (A,1)
`0x03709B`	Password related (E,5)

Weapon Attributes

Mega Buster

0x03DA7C - 0x03DA8F (0x14) = Routine

$DA6C:A5 27     LDA $0027   ;Load single frame input poll
$DA6E:29 02     AND #$02    ;Check bit 2 (Whether player pressed B)
$DA70:F0 2B     BEQ $DA9C   ;If bit 2 not on, player didn't press B, skip to end and leave subroutine
$DA72:A2 04     LDX #$04    ;Loads X with #$04
$DA74:BD 20 04  LDA $0420,X ;Check memory position $0424, status of third projectile slot
$DA77:10 07     BPL $DA80   ;Branch if Bit 7 is not set - Bit 7 of 424 is 1 if a projectile exists and 0 if not. In other words, if a projectile is in this slot, continue, otherwise jump to shooting routine
$DA79:CA        DEX         ;Decrement X
$DA7A:E0 01     CPX #$01    ;Check if X is 1
$DA7C:D0 F6     BNE $DA74   ;If X isn't, branch back to projectile check. This repeats until you have checked all 3 projectile slots
$DA7E:F0 1D     BEQ $DA9C   ;If it is 1, you've checked every projectile slot, end subroutine
$DA80:A9 24     LDA #$24    ;Load Accumulator w/ #$24 
$DA82:20 51 C0  JSR $C051   ;Jump to sound effect routine (Play sound #24, Mega Buster shot)
$DA85:A0 00     LDY #$00    ;Load Y with #$00
$DA87:20 E0 D3  JSR $D3E0   ;Jump to bullet generation routine - X, set by the previous loop, is the projectile slot to create bullet in. Y is bullet type, in this case 0 is Mega Buster shots
$DA8A:A9 0F     LDA #$0F    ;Load Accumulator with #$0F
$DA8C:85 36     STA $0036   ;Set timer for how long it takes MM to lower arm after firing to 15 frames
$DA8E:A9 01     LDA #$01    ;Load Accumulator with #$01
$DA90:85 3D     STA $003D   ;Set sprite for firing this to 1, buster shot (0 is none, 2 is super arm, 3 is throw) 
$DA92:A6 2C     LDX $002C   ;Load $002C, Mega Man's current state, into X
$DA94:18        CLC         ;Always clear carry flag before addition!
$DA95:7D D4 D3  ADC $D3D4,X ;Add something at $D3D4 + $002C's position. I think this is deciding which shooting sprite to use (2C indicates whether MM is standing, jumping, walking, etc). 
$DA98:8D 00 04  STA $0400   ;Store Rockman animation
$DA9B:18        CLC         ;Clear carry
$DA9C:60        RTS         ;We're done here folks

Address	Function	Details	Default value
`0x03D313` `-` `0x03D315` (USA), `0x03D310` `-` `0x03D312` (JPN)	Mega Buster palette		`0F2C11`
`0x03D45F` (USA), `0x03D45C` (JPN)	Projectile type of buster shot		`00`
`0x03D495` (USA), `0x03D492` (JPN)	X-Velocity of buster shot (fraction)		`00`
`0x03D4A7` (USA), `0x03D4A4` (JPN)	X-Velocity of buster shot (integer)	Shots that are too fast will not be able to properly register hits at all, so avoid going beyond around `0B`.	`04`
`0x03D4B9` (USA), `0x03D4B6` (JPN)	Y-Velocity of buster shot (fraction)		`00`
`0x03D4CB` (USA), `0x03D4C8` (JPN)	Y-Velocity of buster shot (integer)		`00`
`0x03DA83` (USA), `0x03DA80` (JPN)	Maximum number of buster shots on-screen	Values `00`, `01`, and `10` and beyond are all invalid, while `02` is actually 1, so `04` would actually mean 3 shots on-screen. What this literally is is how far into the object handling chart in memory ($0420 - $043F) the projectile generation loop is going. Weapons are normally stored in $0422 - $0429, so with a maximum of 3 bullets on screen, the loop checks $0424, $0423, and $0422. Increasing this past 0F enters the enemy handling range ($0430~$043F).	`04`
`0x03DA91` (USA), `0x03DA8E` (JPN)	Sound effect for basic Mega Man shooting		`24`
`0x03E6AA` (USA), `0x03E6A4` (JPN)	Buster shot speed when being deflected		`05`

Atomic Fire

Address	Function	Details	Default value
`0x03D317` `-` `0x03D319` (USA), `0x03D314` `-` `0x03D316` (JPN)	Atomic Fire palette		`0F2815`
`0x03DD61`	Charge time between first and second level		`7D`
`0x03DD67`	Charge time between first and third level	If this value is lower than the value above, then that value is overwritten and it jumps straight to the third charge level.	`BB`
`0x03DE46` `-` `0x03DE48`	Sound effect for Atomic Heat charge per level		`35`, `36`, `37`
`0x03DE49` `-` `0x03DE50`	First and third color of Atomic Heat per level, including non-charging		`0F15`, `3115`, `352C`, `3030`
`0x03DE55` `-` `0x03DE57`	Amount of energy that Atomic Heat uses per shot per level		`01`, `06`, `0A`
`0x03DDF1`	Atomic Fire x-speed	Applies to all levels	`04`

Air Shooter

0x03DAC3 - 0x03DAF5 (0x33) = Routine

$DAB3:A5 27     LDA $0027 = #$00
$DAB5:29 02     AND #$02
$DAB7:F0 2B     BEQ $DAE4
$DAB9:A2 04     LDX #$04
$DABB:BD 20 04  LDA $0420,X @ $0480 = #$40
$DABE:30 24     BMI $DAE4
$DAC0:CA        DEX
$DAC1:E0 01     CPX #$01
$DAC3:D0 F6     BNE $DABB
$DAC5:A2 04     LDX #$04
$DAC7:86 01     STX $0001 = #$74
$DAC9:A0 02     LDY #$02
$DACB:20 E0 D3  JSR $D3E0
$DACE:A6 01     LDX $0001 = #$74
$DAD0:CA        DEX
$DAD1:E0 01     CPX #$01
$DAD3:D0 F2     BNE $DAC7
$DAD5:A9 3F     LDA #$3F
$DAD7:20 51 C0  JSR $C051
$DADA:38        SEC
$DADB:A5 9D     LDA $009D = #$16
$DADD:E9 02     SBC #$02
$DADF:85 9D     STA $009D = #$16
$DAE1:4C 8A DA  JMP $DA8A
$DAE4:38        SEC
$DAE5:60        RTS

Address	Function	Details	Default value
`0x03D31B` `-` `0x03D31D` (USA), `0x03D318` `-` `0x03D31A` (JPN)	Air Shooter palette		`0F3011`
`0x03DAE6`	Sound effect for Air Shooter		`3F`
`0x03DAEE`	Amount of energy that Air Shooter uses per shot		`02`

Leaf Shield

Address	Function	Details	Default value
`0x03D31F` `-` `0x03D321` (USA), `0x03D31C` `-` `0x03D31E` (JPN)	Leaf Shield palette		`0F3019`
`0x03DF0D`	Sound effect for Leaf Shield turning		`01`
`0x03DF1F`	Sound effect for Leaf Shield appearing		`31`
`0x03DF72`	Amount of energy that Leaf Shield uses per shot		`03`

Bubble Lead

Address	Function	Details	Default value
`0x03D323` `-` `0x03D325` (USA), `0x03D320` `-` `0x03D322` (JPN)	Bubble Lead palette		`0F3000`
`0x03DB34`	Bubble Lead x-speed		`01`
`0x03DB34`	Sound effect for Bubble Lead		`24`
`0x03DB3D`	Amount of Bubble Lead shots before reducing energy		`02`

Quick Boomerang

0x03DB4B - 0x03DB89 (0x3F) = Routine

$DB3B:A5 27     LDA $0027 = #$00
$DB3D:29 02     AND #$02
$DB3F:D0 0A     BNE $DB4B
$DB41:A5 AB     LDA $00AB = #$03
$DB43:C9 0B     CMP #$0B
$DB45:F0 04     BEQ $DB4B
$DB47:E6 AB     INC $00AB = #$03
$DB49:18        CLC
$DB4A:60        RTS
$DB4B:A2 05     LDX #$05
$DB4D:BD 20 04  LDA $0420,X @ $0425 = #$C3
$DB50:10 07     BPL $DB59
$DB52:CA        DEX
$DB53:E0 01     CPX #$01
$DB55:D0 F6     BNE $DB4D
$DB57:F0 1F     BEQ $DB78
$DB59:A0 05     LDY #$05
$DB5B:20 E0 D3  JSR $D3E0
$DB5E:A9 24     LDA #$24
$DB60:20 51 C0  JSR $C051
$DB63:E6 AC     INC $00AC = #$04
$DB65:A5 AC     LDA $00AC = #$04
$DB67:C9 08     CMP #$08
$DB69:D0 06     BNE $DB71
$DB6B:A9 00     LDA #$00
$DB6D:85 AC     STA $00AC = #$04
$DB6F:C6 A0     DEC $00A0 = #$09
$DB71:A9 00     LDA #$00
$DB73:85 AB     STA $00AB = #$03
$DB75:4C 8A DA  JMP $DA8A
$DB78:38        SEC
$DB79:60        RTS

Address	Function	Details	Default value
`0x03D327` `-` `0x03D329` (USA), `0x03D324` `-` `0x03D326` (JPN)	Quick Boomerang palette		`0F3425`
`0x03DB54`	Fire rate velocity for Quick Boomerang		`0B`
`0x03DB6F`	Sound effect for Quick Boomerang		`24`
`0x03DB78`	Amount of Quick Boomerang shots before reducing energy		`08`

Quick Boomerang Mechanics

0x03DFDE - 0x03E025 (0x48) = Routine

$DFCE:BD E0 04  LDA $04E0,X @ $04E3 = #$0D
$DFD1:C9 12     CMP #$12
$DFD3:B0 14     BCS $DFE9
$DFD5:38        SEC
$DFD6:BD 60 06  LDA $0660,X @ $0663 = #$DB
$DFD9:E9 4B     SBC #$4B
$DFDB:9D 60 06  STA $0660,X @ $0663 = #$DB
$DFDE:BD 40 06  LDA $0640,X @ $0643 = #$FE
$DFE1:E9 00     SBC #$00
$DFE3:9D 40 06  STA $0640,X @ $0643 = #$FE
$DFE6:4C 0F E0  JMP $E00F
$DFE9:D0 08     BNE $DFF3
$DFEB:BD 20 04  LDA $0420,X @ $0423 = #$C3
$DFEE:49 40     EOR #$40
$DFF0:9D 20 04  STA $0420,X @ $0423 = #$C3
$DFF3:BD E0 04  LDA $04E0,X @ $04E3 = #$0D
$DFF6:C9 23     CMP #$23
$DFF8:D0 04     BNE $DFFE
$DFFA:5E 20 04  LSR $0420,X @ $0423 = #$C3
$DFFD:60        RTS
$DFFE:18        CLC
$DFFF:BD 60 06  LDA $0660,X @ $0663 = #$DB
$E002:69 4B     ADC #$4B
$E004:9D 60 06  STA $0660,X @ $0663 = #$DB
$E007:BD 40 06  LDA $0640,X @ $0643 = #$FE
$E00A:69 00     ADC #$00
$E00C:9D 40 06  STA $0640,X @ $0643 = #$FE
$E00F:FE E0 04  INC $04E0,X @ $04E3 = #$0D
$E012:20 EF EE  JSR $EEEF
$E015:60        RTS

Address	Function	Details	Default value
`0x03DFE2`	How far Quick Boomerang flies out		`12`
`0x03DFFF`	How far Quick Boomerang flies down before coming up		`40`
`0x03E007`	How far Quick Boomerang flies back		`23`

Flash Stopper

0x03DC41 - 0x03DC5C (0x1C) = Routine

$DC31:A5 27     LDA $0027 = #$00
$DC33:29 02     AND #$02
$DC35:F0 1F     BEQ $DC56
$DC37:A2 02     LDX #$02
$DC39:AD 22 04  LDA $0422 = #$00
$DC3C:30 18     BMI $DC56
$DC3E:A0 08     LDY #$08
$DC40:20 E0 D3  JSR $D3E0
$DC43:A9 01     LDA #$01
$DC45:8D A6 05  STA $05A6 = #$01
$DC48:A9 21     LDA #$21
$DC4A:20 51 C0  JSR $C051

Address	Function	Details	Default value
`0x03D32B` `-` `0x03D32D` (USA), `0x03D328` `-` `0x03D32A` (JPN)	Flash Stopper palette		`0F3414`
`0x03DC59`	Sound effect for Flash Stopper		`21`

Flash Stopper Mechanics

0x03E168 - 0x03E19F (0x38) = Routine

$E158:DE 20 06  DEC $0620,X @ $0680 = #$03
$E15B:D0 15     BNE $E172
$E15D:A9 0F     LDA #$0F
$E15F:9D 20 06  STA $0620,X @ $0680 = #$03
$E162:C6 A1     DEC $00A1 = #$1C
$E164:D0 0C     BNE $E172
$E166:5E 20 04  LSR $0420,X @ $0480 = #$00
$E169:A9 00     LDA #$00
$E16B:85 AA     STA $00AA = #$00
$E16D:A9 01     LDA #$01
$E16F:85 50     STA $0050 = #$00
$E171:60        RTS
$E172:A9 01     LDA #$01
$E174:85 AA     STA $00AA = #$00
$E176:A9 00     LDA #$00
$E178:85 50     STA $0050 = #$00
$E17A:85 4F     STA $004F = #$00
$E17C:A9 80     LDA #$80
$E17E:9D A0 04  STA $04A0,X @ $0500 = #$A6
$E181:18        CLC
$E182:65 1F     ADC $001F = #$00
$E184:9D 60 04  STA $0460,X @ $04C0 = #$00
$E187:AD 40 04  LDA $0440 = #$00
$E18A:69 00     ADC #$00
$E18C:9D 40 04  STA $0440,X @ $04A0 = #$B4
$E18F:60        RTS

Address	Function	Details	Default value
`0x03D49D`	Duration until weapon energy starts to drain		`0F`
`0x03E16E`	Every nth frame to drain one bar of weapon energy		`0F`

Metal Blade

0x03DC5D - 0x03DC65 (0x9) = Routine

$DC4D:A9 0F     LDA #$0F
$DC4F:85 36     STA $0036 = #$00
$DC51:A9 03     LDA #$03
$DC53:4C 90 DA  JMP $DA90
$DC56:38        SEC
$DC57:60        RTS

Address	Function	Details	Default value
`0x03D32F` `-` `0x03D331` (USA), `0x03D32C` `-` `0x03D32E` (JPN)	Metal Blade palette		`0F3718`
`0x03DBC9`	Sound effect for Metal Blade		`23`
`0x03DBD2`	Amount of Metal Blade shots before reducing energy		`04`

Crash Bomber

Address	Function	Details	Default value
`0x03D333` `-` `0x03D335` (USA), `0x03D330` `-` `0x03D332` (JPN)	Crash Bomber palette		`0F3026`
`0x03DBA6`	Sound effect for Crash Bomber		`24`
`0x03DB99`	Amount of energy that Crash Bomber uses per shot		`04`
`0x03E089`	Sound effect for Crash Bomber clasping wall		`2E`
`0x03E09C`	Timer until Crash Bomber detonates		`7E`
`0x03E0DA`	Sound effect for Crash Bomber exploding		`2B`

Items

Address	Function	Details	Default value
`0x03D337` `-` `0x03D339` (USA), `0x03D334` `-` `0x03D336` (JPN)	Item 1 palette		`0F3016`
`0x03D33B` `-` `0x03D33D` (USA), `0x03D338` `-` `0x03D33A` (JPN)	Item 2 palette		`0F3016`
`0x03D33F` `-` `0x03D341` (USA), `0x03D33C` `-` `0x03D33E` (JPN)	Item 3 palette		`0F3016`
`0x03DC85`	Amount of energy that Item 1 uses per use		`02`
`0x03E230`	Amount of time before subtracting one energy from Item 2		`13`
`0x03E34C`	Amount of time before subtracting one energy from Item 3		`1F`

Enemy Behavior

Attack Power Table

Address	Function	Details	Default value
`0x02E9C4`	Wood Man's contact damage		`08`
`0x02E9C8`	Flash Man's contact damage		`06`
`0x03ED6C`	Normal Shrink's contact damage		`04`
`0x03ED6D`	Lantern Fish Shrink's contact damage		`04`
`0x03ED74`	Snapper's contact damage		`04`
`0x03ED76`	Crabbot's contact damage		`04`
`0x03ED77`	Crabbot's shell damage		`04`
`0x03ED78`	Grand Croaker's contact damage		`04`
`0x03ED79`	Petit Croaker's contact damage		`01`
`0x03ED82`	Bubble Bat's contact damage		`04`
`0x03ED83`	Robo-Rabbit's contact damage		`04`
`0x03ED84`	Robo-Rabbit's projectile carrot		`02`
`0x03ED85`	Hot Dog's contact damage		`08`
`0x03ED87`	Hot Dog's projectile fire stream		`04`
`0x03ED89`	Mecha Monkey's contact damage		`04`
`0x03ED8B`	Atomic Chicken's contact damage		`04`
`0x03EDA1`	Returning Sniper Joe's projectile pellet		`02`
`0x03EDA4`	Pipi's contact damage		`04`
`0x03EDA6`	Pipi's egg projectile		`04`
`0x03EDA8`	Copipi's contact damage		`02`
`0x03EDB7`	Crazy Cannon's contact damage		`04`
`0x03EDB9`	Crazy Cannon's projectile pellet		`02`
`0x03EDBA`	Sniper Armor's contact damage		`08`
`0x03EDBB`	Sniper Armor's projectile pellet		`04`
`0x03EDBC`	Schworm's contact damage		`02`
`0x03EDBD`	Schworm's projectile snake rod		`02`
`0x03EDCD`	Wood Man's Leaf Shield		`08`
`0x03EDCE`	Wood Man's Falling Leaves		`04`

Heat Man

0x02C16E - 0x02C--- (0x??) = Routine for attack

Address	Function	Details	Default value
`0x02C207`	Atomic Fire 1's y-velocity		`07`
`0x02C208`	Atomic Fire 2's y-velocity		`05`
`0x02C209`	Atomic Fire 3's y-velocity		`03`
`0x02C20A`	Atomic Fire 1's x-velocity	Unlike other instances of velocity, lower values for these x-velocities means faster velocity.	`3A`
`0x02C20B`	Atomic Fire 2's x-velocity		`2E`
`0x02C20C`	Atomic Fire 3's x-velocity		`1C`
`0x02C1BB`	Projectile type		`58`
`0x02C1A1`	Number of Atomic Fires thrown	Extra shots tend to be glitchy.	`02`
`0x02C253`	Charge x-velocity		`04`
`0x02C29D`	Delay 1 before charge	After Heat Man is damaged, he will wait before charging. This and the two values below are randomly chosen as the delay interval.	`1F`
`0x02C29E`	Delay 2 before charge		`3E`
`0x02C29F`	Delay 3 before charge		`5D`

Flash Man

0x02C966 - 0x02CAF8 (0x193 = Routine for attack

Address	Function	Details	Default value
`0x02C97D`	Walk x-velocity fraction		`06`
`0x02C982`	Walk x-velocity integer		`01`
`0x02C98B`	Delay before Time Stopper	It only counts down while the boss is walking.	`BB`
`0x02CA09`	Number of pellets to shoot		`06`
`0x02CA52`	Length of Time Stopper/projectile frequency?	Uncertain about value's function; alter it at own risk.	`06`
`0x02CA71`	Projectile type		`35`
`0x02CA81`	Pellet x-velocity		`08`
`0x02CAC6`	Jump x-velocity integer		`00`
`0x02CACE`	Jump y-velocity integer		`04`

Metal Man

Address	Function	Details	Default value
`0x02CBB5`	Jump height 1	Anything higher than 07 will make Metal Man bonk the ceiling.	`06`
`0x02CBB6`	Jump height 2		`05`
`0x02CBB7`	Jump height 3		`04`
`0x02CC1D`	Metal Blade frequency?	Uncertain about value's function, seems to change behavior if value's different than 06; alter it at own risk.	`06`
`0x02CC29`	Metal Blade sound		`20`
`0x02CC2D`	Projectile type		`5C`
`0x02CC3F`	Metal Blade x-velocity		`04`

Crash Man

Address	Function	Details	Default value
`0x02CCF2`	Walk x-velocity fraction		`47`
`0x02CCF7`	Walk x-velocity integer		`01`
`0x02CD07`	RAM address to check for jumping (see below)	If changed to 0x17, he always jumps. If any value other than 0x27 or 0x17, he doesn't react to your attacks with a jump anymore.	`27`
`0x02CD09`	Button to check for jumping	What it does is that it checks if x button is pressed. Ex. if set to 02, Crash Man will check the B button; if set to 01, he will check the A button instead; if set to 03, Crash Man will check both A and B, etc.	`02`
`0x02CD2A`	Jump y-velocity integer		`06`
`0x02CDAF`	Jump y-velocity fraction		`44`
`0x02CDD3`	If an object of this type currently exists, Crash Man won't shoot when jumping		`5E`
`0x02CDDA`	Projectile type		`5E`
`0x02CDEE`	Crash Bomber x-velocity integer		`06`

Quick Man

Address	Function	Details	Default value
`0x02C86E`	Number of Quick Boomerangs		`03`
`0x02C872`	Projectile type		`59`
`0x02C882`	Quick Boomerang delay in frames before second motion		`25`
`0x02C887`	Boomerang x-velocity first motion		`04`
`0x03B726`	Boomerang x-velocity second motion		`04`
`0x02C8A3`	Medium jump y-velocity		`07`
`0x02C8A4`	High jump y-velocity		`08`
`0x02C8A5`	Low jump y-velocity		`04`
`0x02C8E4`	Running time in frames		`3E`
`0x02C8DF`	Running velocity integer		`02`

Bubble Man

Address	Function	Details	Default value
`0x02C70B`	Landing speed integer		`FF`
`0x02C6D3`	Rising speed integer		`01`
`0x02C74F`	Gun projectile type		`5A`

Wood Man

Address	Function	Details	Default value
`0x02C537`	Delay between rising leaves		`12`
`0x02C5DD`	Jump y-velocity integer		`04`
`0x02C5E2`	Jump x-velocity integer		`01`
`0x02C5A9`	Leaf Shield launch x-velocity integer		`04`
`0x02C553`	Number of falling leaves		`03`
`0x02C576`	Falling leaf x-velocity integer		`02`
`0x02C567`	Falling leaf y-position start		`20`
`0x02C522`	Leaf Shield projectile type		`61`
`0x02C557`	Falling leaves projectile type		`62`
`0x02C542`	Rising leaves projectile type		`62`
`0x03DA34`	Leaf Shield fall y-velocity?	Uncertain about value's function; alter it at own risk.	`00`
`0x03D8F6`	Unsure; changing this value to `06` makes an interesting Leaf Shield pattern.		`02`
`0x03B855`	Leaf fall y-velocity?	Uncertain about value's function; alter it at own risk. Unlike other instances of velocity, lower values means faster velocity. Values `40` and higher make it so that it doesn't fall. Low numbers make leaves instantly despawn, causing faster patterns	`20`

Air Man

0x02C2F3 - 0x02C50A (0x218) = Routine for attack
0x02C30C = Number of tornado patterns before jump phase 03
0x02C393 - 0x02C428 (0x96) = Tornado properties [NOTE: Air Man has 5 possible tornado patterns, each with 6 tornadoes. In each 30-byte block of properties, the first 6 bytes correspond to the tornadoes in the first pattern, the next 6 bytes correspond to the tornadoes in the second pattern, etc.]
- 0x02C393 - 0x02C3B0 (0x1E) = y-velocity fractions
- 0x02C3B1 - 0x02C3CE (0x1E) = y-velocity integers
- 0x02C3CF - 0x02C3EC (0x1E) = x-velocity fractions
- 0x02C3ED - 0x02C40A (0x1E) = x-velocity integers
- 0x02C40B - 0x02C428 (0x1E) = delay before tornado finishes deploying
0x02C4DD = First jump y-velocity fraction E6
0x02C4DE = Second jump y-velocity fraction 76
0x02C4E0 = First jump y-velocity integer 04
0x02C4E1 = Second jump y-velocity integer 07
0x02C4E3 = First jump x-velocity fraction 39
0x02C4E4 = Second jump x-velocity fraction 9A
0x02C4E6 = First jump x-velocity integer 01
0x02C4E7 = Second jump x-velocity integer 01

Wily Machine

Address	Function	Details	Default value
`0x02DA2E`	Phase 1 weakness #1 to disable	Only one damage table is provided for Wily Machine's weaknesses. However, during each phase, the game manually ignores damage when you have certain weapons equipped. By default, damage is negated if you have Air Shooter or Quick Boomerang equipped in phase 1, or if you have Atomic Fire equipped in phase 2.	`02`
`0x02DA32`	Phase 1 weakness #2 to disable		`05`
`0x02DA3A`	Phase 2 weakness to disable		`01`

Boss Weakness Damage

(Credit to Overseer190)

[NOTE: This is based on the USA version of Mega Man 2. Japanese values are located further up in the ROM (specifically starting from 2E933). Also, any hex value from 00 to 7F (0 to 127) deals damage to the enemy, whereas hex values ranging from 80 to FF (128 to 255) will fully heal the enemy.]

Mega Buster

Address	Boss	Details	Default value
`0x02E952`	Heat Man		`02`
`0x02E953`	Air Man		`02`
`0x02E954`	Wood Man		`01`
`0x02E955`	Bubble Man		`01`
`0x02E956`	Quick Man		`02`
`0x02E957`	Flash Man		`02`
`0x02E958`	Metal Man		`01`
`0x02E959`	Crash Man		`01`
`0x02E95A`	Mecha Dragon		`01`
`0x02E95B`	Picopico-kun		`00`
`0x02E95C`	Guts Tank		`01`
`0x02E95D`	Boobeam Trap		`00`
`0x02E95E`	Wily Machine 2		`01`
`0x02E95F`	Alien		`FF`

Atomic Fire

An uncharged shot uses the Mega Buster's damage chart, a partially charged shot uses the Mega Buster's damage chart and multiplies the value by 2, and a charged shot uses the table below.

Address	Boss	Details	Default value
`0x02E960`	Heat Man		`FF`
`0x02E961`	Air Man		`06`
`0x02E962`	Wood Man		`0E`
`0x02E963`	Bubble Man		`00`
`0x02E964`	Quick Man		`0A`
`0x02E965`	Flash Man		`06`
`0x02E966`	Metal Man		`04`
`0x02E967`	Crash Man		`06`
`0x02E968`	Mecha Dragon		`08`
`0x02E969`	Picopico-kun		`00`
`0x02E96A`	Guts Tank		`08`
`0x02E96B`	Boobeam Trap		`00`
`0x02E96C`	Wily Machine 2		`0E`
`0x02E96D`	Alien		`FF`

Air Shooter

Address	Boss	Details	Default value
`0x02E96E`	Heat Man		`02`
`0x02E96F`	Air Man		`00`
`0x02E970`	Wood Man		`04`
`0x02E971`	Bubble Man		`00`
`0x02E972`	Quick Man		`02`
`0x02E973`	Flash Man		`00`
`0x02E974`	Metal Man		`00`
`0x02E975`	Crash Man		`0A`
`0x02E976`	Mecha Dragon		`00`
`0x02E977`	Picopico-kun		`00`
`0x02E978`	Guts Tank		`00`
`0x02E979`	Boobeam Trap		`00`
`0x02E97A`	Wily Machine 2		`01`
`0x02E97B`	Alien		`FF`

Leaf Shield

Address	Boss	Details	Default value
`0x02E97C`	Heat Man		`00`
`0x02E97D`	Air Man		`08`
`0x02E97E`	Wood Man		`FF`
`0x02E97F`	Bubble Man		`00`
`0x02E980`	Quick Man		`00`
`0x02E981`	Flash Man		`00`
`0x02E982`	Metal Man		`00`
`0x02E983`	Crash Man		`00`
`0x02E984`	Mecha Dragon		`00`
`0x02E985`	Picopico-kun		`00`
`0x02E986`	Guts Tank		`00`
`0x02E987`	Boobeam Trap		`00`
`0x02E988`	Wily Machine 2		`00`
`0x02E989`	Alien		`FF`

Bubble Lead

Address	Boss	Details	Default value
`0x02E98A`	Heat Man		`06`
`0x02E98B`	Air Man		`00`
`0x02E98C`	Wood Man		`00`
`0x02E98D`	Bubble Man		`FF`
`0x02E98E`	Quick Man		`00`
`0x02E98F`	Flash Man		`02`
`0x02E990`	Metal Man		`00`
`0x02E991`	Crash Man		`01`
`0x02E992`	Mecha Dragon		`00`
`0x02E993`	Picopico-kun		`00`
`0x02E994`	Guts Tank		`01`
`0x02E995`	Boobeam Trap		`00`
`0x02E996`	Wily Machine 2		`00`
`0x02E997`	Alien		`01`

Quick Boomerang

Address	Boss	Details	Default value
`0x02E998`	Heat Man		`02`
`0x02E999`	Air Man		`02`
`0x02E99A`	Wood Man		`00`
`0x02E99B`	Bubble Man		`02`
`0x02E99C`	Quick Man		`00`
`0x02E99D`	Flash Man		`00`
`0x02E99E`	Metal Man		`04`
`0x02E99F`	Crash Man		`01`
`0x02E9A0`	Mecha Dragon		`01`
`0x02E9A1`	Picopico-kun		`00`
`0x02E9A2`	Guts Tank		`02`
`0x02E9A3`	Boobeam Trap		`00`
`0x02E9A4`	Wily Machine 2		`01`
`0x02E9A5`	Alien		`FF`

Crash Bombs

Address	Boss	Details	Default value
`0x02E9A6`	Heat Man		`FF`
`0x02E9A7`	Air Man		`00`
`0x02E9A8`	Wood Man		`02`
`0x02E9A9`	Bubble Man		`02`
`0x02E9AA`	Quick Man		`04`
`0x02E9AB`	Flash Man		`03`
`0x02E9AC`	Metal Man		`00`
`0x02E9AD`	Crash Man		`00`
`0x02E9AE`	Mecha Dragon		`01`
`0x02E9AF`	Picopico-kun		`00`
`0x02E9B0`	Guts Tank		`01`
`0x02E9B1`	Boobeam Trap	This value is unused as Boobeam Traps take 4 damage from being hit by "a weapon that does not have a 'no hit' flag." The location of this flag is unknown.	`00`
`0x02E9B2`	Wily Machine 2		`04`
`0x02E9B3`	Alien		`FF`

Metal Blade

Address	Boss	Details	Default value
`0x02E9B4`	Heat Man		`01`
`0x02E9B5`	Air Man		`00`
`0x02E9B6`	Wood Man		`02`
`0x02E9B7`	Bubble Man		`04`
`0x02E9B8`	Quick Man		`00`
`0x02E9B9`	Flash Man		`04`
`0x02E9BA`	Metal Man		`0E`
`0x02E9BB`	Crash Man		`00`
`0x02E9BC`	Mecha Dragon		`00`
`0x02E9BD`	Picopico-kun		`00`
`0x02E9BE`	Guts Tank		`00`
`0x02E9BF`	Boobeam Trap		`00`
`0x02E9C0`	Wily Machine 2		`01`
`0x02E9C1`	Alien		`FF`

Mega Man 2/ROM map: Difference between revisions

Latest revision as of 14:27, 24 January 2024

Gameplay Data

Mega Man

Heads-Up Display

READY Sprites

Sound Effects during Stage

Pause Menu

Arrow and NEXT Sprites

Weapon Icon Sprites

E-Tank Menu Sprite

Extra Life Menu Sprite

Items

Power Ups

Screen Data

Stage Select

Wily Castle

Wily Castle Dots

Weapon Get Screens

Mega Man

Dr. Light

Title

Password

Sprites

Positions

Weapon Attributes

Mega Buster

Atomic Fire

Air Shooter

Leaf Shield

Bubble Lead

Quick Boomerang

Quick Boomerang Mechanics

Flash Stopper

Flash Stopper Mechanics

Metal Blade

Crash Bomber

Items

Enemy Behavior

Attack Power Table

Heat Man

Flash Man

Metal Man

Crash Man

Quick Man

Bubble Man

Wood Man

Air Man

Wily Machine

Boss Weakness Damage

Mega Buster

Atomic Fire

Air Shooter

Leaf Shield

Bubble Lead

Quick Boomerang

Crash Bombs

Metal Blade

Navigation menu

Search