Animated tiles questions

[Vener]

Let's take an exemple with crateria lake tiles :

$87:825D             dw 8192,0200,1B00


$87:8192  ; instructions list :           

                           dw 000A,8564,
                                000A,8764,
                                000A,8964,
                                000A,8764,
                                80B7,8192   

number of tiles to transfer to VRAM (4 in this exemple)

VRAM adresse to store tiles : How to determinate where is the VRAM adresse to use ? I mean , each animated tiles have their own VRAM adresse , so , how to define which tile go to which adresse ?

???? : For PLMs/ENNEMYs , this pointer lead to the tilemap , but here , i don't understand what is the signification since it's not a tilemap pointed there (or then , it's a very very strange format). it seems to point to the uncompressed tile GFX itself ...

For a simple one animated tile , like spike block or wrecked ship screen , i understand that there is no need to do a tilemap since it's juste one tile . 

But here , the instruction list seems to rotate only the [tile 1] with 3 tiles . How the game can do the same rotating stuff for [tile 2][tile 3]&[tile 4] ?


Crateria lake tiles animation is like this [tile 1][tile 2]
                                                         [tile 3][tile 4]       

                                                               
                                                         


and also , the animated tiles are always in the scenery , but what determinate the tile# in the scenery ?
Exemple: if i want to use the tile #7D in the scenery for my new animated tile , where to specify it ? it is determinated with the VRAM adresse used ?

Thanks for the one which can answer

[Moehr]

If you know the current VRAM address for a given tile, you can add $20 to it's value to take the tile to the right, or subtract $20 to get the tile to the left.

The animated tiles replace tiles in the gfx sheet, but get flipped via how you set them up in the tile table.

The other questions I can't help with at the moment .