Tiles etc..

[KuJi]

In New Features 2001:

This is one line of the background layer. 'tilesdata' has a length if w*2
characters; each tile is a 12bit-index into the tile list (pics1.png) and is
encoded in two base64 characters (upper 6 bit first)
base64: String = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvw xyz0123456789+/'
so AA is tile 0, AB is tile 1, AC is tile 2, // is tile 4095 (=0xFFF)

Can someone explain on how to find what the tiles are. EX: 0xABC = what?