Bubble Bobble (NES, Famicom Disk System)/RAM map

The following article is a RAM map for Bubble Bobble (NES, Famicom Disk System).

Global Variables

• 0401 - Current Level (Level 1 = $01)
• 045D - Super Bubble Bobble switch
• 04C4 - Altering this changes the enemy sprites. Probably an offset position for reading data from the pattern image.

Menu Variables

• 0402 - Option selected on main menu
• 0502-0506 - Password letters (A-J = $00-$09)

Player Variables

• 002E - P1 remaining lives
• 003F - P1 invincibility timer (odd = invisible, even = visible)
• 0042 - P2 remaining lives
• 0053 - P2 invincibility timer (odd = invisible, even = visible)

Counter Variables

These are the combined total for both players.

• 0435 - Counter for bubbles blown (E5DF)
• 0436 - Counter for empty bubbles popped (E5E0)
• 043A - Counter for number of times fallen through floor
• 043B - Counter for fruits eaten
• 0476 - Counter for filled bubbles popped

Here's a list of arcade counters for anyone who is curious; I'm not sure how many are in the NES version or what order they're in.

E5DF = Bubbles Blown (0435 NES)
E5E0 = Empty Bubbles Popped (0436 NES)
E5E1 = Lightning Bubbles Popped
E5E2 = Fire bubbles popped
E5E3 = Water bubbles popped
E5E4 = Jumps
E5E5 = Distance run
E5E6 = Distance run 2
E5E7 = Wraparounds
E5E8 = Monster fruits (043B)
E5E9 = Fast sweeties
E5EA = rapid fire
E5EB = long range
e5ec = umbrellas
e5ed = clocks
e5ee = monsters drowned
e5ef = p1 joins
e5f0 = p2 joins
e5f3 = kills by fire bubble
e5f4 = kills by lightning
e5f6 = special items eaten
e5f7 = special fruits eaten
e5f8 = E
e5f9 = X
e5fa = T
e5fb = E
e5fc = N
e5fd = D
e5fe = hurry up
e5ff = yellow/red crosses
e600 = water cross
e601 = books
e602 = purple lanterns
e604 = "JAX" on high score table
e605 = flamingo
e606 = kit
e607 = ...
e608 = entries of 'I.F', 'MTJ', 'NSO', 'KIM' or 'YSH' into high score table
e609 = crown
e60a = 777 levels
e60d = level 19, no deaths
e60e = level 29, no deaths
e60f = level 39, no deaths
e610 = level 49, no deaths
e611 = skel

Bonus Round Variables

• 042F - Amount of remaining treasures during Bonus Game
• 0430 - Bonus Round timer
• 0431 - P1 treasures collected in Bonus Round
• 0433 - P2 treasures collected in Bonus Round
• 045F - Bonus Round switch (set to $01+ to activate the bonus game, as if picking up the bottle)

Level Variables

• 0405 - Queue for EXTEND letters (Only 3 will come per level, any queue excess will be cleared at the beginning of the next level with openings)
• 040D - Timer countdown until "Hurry!" appears. This set to 040E at the beginning of each level.
• 040E - What the "Hurry!" timer countdown (040D) is set to at the beginning of a level. Varies from level to level.
• 044D - Remaining levels to be skipped by an umbrella. If > 0 when all the enemies on the level are defeated, you will being skipping levels. You can only skip 31 levels max. If the variable is set above $1F(31), skipping will occur again after the defeat of the enemies. This will continue until the variable = 0.
• 045E - Timer going up (Item appearances/disappearances may be relative to it)
• 04CD - Point Item position [on Level 1, it positions the item diagonally from the upper-left corner ($00) to the lower-right corner ($FF)]
• 04CE - Appearance of Elemental Bubbles ($00-$1F = Nothing/????, $20-$3F = Water Bubbles, $40-$5F = Fire Bubbles, $60+ Fire Bubbles over Water Bubbles and other odd combinations)

End Boss Variables

• 006F - Super Drunk's HP

Miscellaneous Variables

• 0445-044B - Variables representing each digit of the last scorer's score.
  

- 0445 is millions
- 0446 is hundred thousands
- 0447 is ten thousands
- 0448 is thousands
- 0449 is hundreds
- 044A is tens
- 044B is ones
$27 seems to represent a blank space. These reset to $27 (36) at the beginning of each level. Could possibly be related to how the on-screen score information is redrawn.