my matrix work too badly for doing a serious debugging.. but i can publish now the mods for using 64 butons directly connected . sorry if my programmation is not really optimised, but it's working. first, in mios_table.inc, add entry for the 64 butons after the original buttons: then , you have to set in main.asm the gp-butons SR on 0: the gp butons still work with the menu buton: you can press any button of any rows. if the menu page called is relative to track number, pressing e.g. gp buton "event" of row 1 will make the menu jump to "event" for track one, if you press gp buton "event" of row 2, to "event" of track 2... then, in "seq_buttons.inc", add this code after this lines: ... SEQ_BUTTON_GP_Cont movwf MIOS_PARAMETER1 goto SEQ_GP_Button : that's all. i'm sure anyone can do simpler or much effective, but this work... i will tell you if there is any side effect as soon as the whole hardware will be build. TK: i promise you to build another matrix to seriously test your code , so you don't spend time for me for nothing...