this is the PRX i know and love
13-0-------13-0-13-0-----------------------------------13-0-13-0-13-0
13-0-----13-0------13-0------------------------------ 13-0-----------13-0
13-0------------------13-0------------------------------13-0--------------13-0
13-0-----------13-0-13-0-------13-0-13-0------13-0---------------13-0
13-0-------------------13-0-------13-0-13-0------13-0---------------13-0
13-0-------------------13-0-----------------------------13-0-------------13-0
13-0-----13-0-------13-0------------------------------13-0-----------13-0
13-0---------13-0-13-0---------------------------------13-0-13-0-13-0