Browsing a PGN chess game is similar to browse a database table, the records being the FEN strings corresponding to successive positions of the game; the problem here is to obtain these FENs. Another problem is using different sets of chessmen, with minimum changes (or additions) to the chess diagram CSS definition.

We create a DOM + CSS homogeneous infrastructure, for providing the chess diagram and DIV's for the moves list, annotations etc., using several sprites of 12 NxN px chessmen (from which the pieces are positioned in the diagram fields with background-position: -K*100% (K=1..N), independently of N).

On the other hand, we create a 0x88 reprezentation (BOARD[] array of 128 integers for the chessboard, position flags, 32-bit MOVE) and corresponding infrastructure (moves generator, _makeMove()) - used for to validate the PGN moves for legality (by converting from SAN to 32-bit moves and succesively making the moves on the BOARD[]); so we also obtain the necessary FENs.

Finally, we bind together these two infrastructures - successively validating and inserting the PGN moves as links (with corresponding handlers) in the moves list DIV (and the annotations in corresponding DIV).