first because i dont know where to get my hands on to modify that source code: i guess the logic of handling arrays and collision is basically the same but display have no clue: i code in javascript actionscrtipt 1 and php and used zx basic but blitz is definitely different: did look for tutorials very base level but found little stuff so far
second, because my fnal purpose is to create a version of the old flashpoint arcade, that is based on tetris logic plus some little additions (now is more a beat the level game than a puzzle one) so having a working tetris base i could just add modifications - did it on a tetris flash so more or less i know what to add but lack basics to do it on blitz.