Puyo Puyo Tsu stores all information related to the current game into memory (RAM), while the system is running. This is lost every time the system is powered off, but is actually where the magic happens: that's where your puyos get stored as you place them on your board, and that's where the upcoming pairs are stored as well, after being generated through an obscure algorithm.
The memory mappings of game structures in RAM are the same between arcade and console versions of the game.
Game state overview
An overview of a running game looks like this:
Puyo Puyo Tsu in-memory game state
Main memory locations
Here are the main locations regarding puyo storage and their generation in the game (offsets are applicable to both genesis and C-2 versions):
Address range / offset
Size
Description
0xFF8000 - 0xFF80A7
168 bytes
board (player 1)
0xFF8800 - 0xFF88A7
168 bytes
board (player 2)
0xFF85A0
6 bytes
P1 upcoming pairs (the two displayed on screen + one after that)
0xFF8DA0
6 bytes
P2 upcoming pairs
0xFFAD00
256 bytes
randomized pool of upcoming pairs (128 pairs), usually 3-color set (difficulty levels 1-2)
0xFFAE00
256 bytes
randomized pool of upcoming pairs (128 pairs), usually 4-color set (difficulty level 3)
0xFFAF00
256 bytes
randomized pool of upcoming pairs (128 pairs), usually 5-color set (difficulty levels 4-5)
0xFFD080
variable
multiple chunks of 64 bytes representing part of the current game's state, including the currently falling pair
0xFFA134
4 bytes
4-byte value that is the last generated random number
