04 BB 03 07 00 05 02 06 01   17 10 16 11 15 12 13 14                            
74 BB 73 77 70 75 72 76 71   67 60 66 61 65 62 63 64                            

I decode like this :                                                                                 
                                                                                
                                                                                
Type of piece   K FF  Q  R  R  B  B  N  N    P  P  P  P  P  P  P  P  
white or black 04 BB 03 07 00 05 02 06 01   17 10 16 11 15 12 13 14  
black or white 74 BB 73 77 70 75 72 76 71   67 60 66 61 65 62 63 64  

                                                                                
FF for flags (for 2 roques and "prise en passant")        

The number are XY in the chessboard, beginning by H1, G1...A1,H2,G2...                  
                                                                                
00 01 02 03 04 05 06 07        H1............A1                                 
10 11 12 13 14 15 16 17                                                         
20 21 22 23 24 25 26 27                                                         
30 31 32 33 34 35 36 37                                                         
40 41 42 43 44 45 46 47                                                         
50 51 52 53 54 55 56 57                                                         
60 61 62 63 64 65 66 67                                                         
70 71 72 73 74 75 76 77        H8............A8