@dmilligan: OK your hint was good!
0x00 => 0000 0000 => 000 000 00 (ISO 100)
0x24 => 0010 0100 => 001 001 00 (ISO 200)
0x48 => 0100 1000 => 010 010 00 (ISO 400)
0x6c => 0110 1100 => 011 011 00 (ISO 800)
0x90 => 1001 0000 => 100 100 00 (ISO 1600)
0x00 => 0000 0000 => 000 000 00 (ISO 100)
0x24 => 0010 0100 => 001 001 00 (ISO 200)
0x48 => 0100 1000 => 010 010 00 (ISO 400)
0x6c => 0110 1100 => 011 011 00 (ISO 800)
0x90 => 1001 0000 => 100 100 00 (ISO 1600)