Bubble Bobble (NES)/RAM map

The following article is a RAM map for Bubble Bobble (NES).

Global Variables

• 001F - Permanent Frame Counter
• 0401 - Current Level (01 = Level 1)
• 045D - Super Bubble Bobble switch

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

Counter variables determine what kind of special item will appear at the start of the next level, according to specific player actions. When a counter reaches a certain threshold (from a table in ROM), the corresponding item code is loaded in $040B and the counter is reset to 0. If more than one counter reach their threshold, the lowest in the list has priority.

• 435 - Bubbles Blown
• 436 - Empty Bubbles Popped
• 437 - Jumps on Bubble
• 438 - Fire Bubbles Popped
• 439 - Water Bubbles Popped
• 43A - Times Fallen Through Floor
• 43B - Enemy Items Taken
• 43C - Enemies Killed by Water
• 43D - Enemies Killed by Lightning
• 43E - Enemies Killed by Fire
• 43F - Special Items Taken
• 440 - Lightning Bubbles Popped
• 441 - Enemy Combo Kills (2 or more)
• 442 - Point Items Taken
• 443 - Letter Bubbles Popped

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 (01 = Bonus Round Activated)

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)
• 040B - Special Item Code
• 040D - Timer countdown until "Hurry Up!" 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 begin 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 for Items (ascending, counts seconds)
• 0492 - Enemy Anger Level Code
• 04CC - Special Item Position
• 04CD - Point Item Position
• 04CE - Appearance of Elemental Bubbles (bits 5-7)

End Boss Variables

• 006F - Super Drunk's HP

Miscellaneous Variables

• 445 - Score Digit x..... (1,000,000s)
• 446 - Score Digit .x....
• 447 - Score Digit ..x...
• 448 - Score Digit ...x..
• 449 - Score Digit ....x.
• 44A - Score Digit .....x (10s)