> SYSTEM.PUT(SYSTEM.ADR(rx), 0); Sets four consecutive bytes to 0, i.e. rx.hd.valid := 0; rx.hd.dadr := 0; rx.hd.sadr := 0; rx.hd.typ := 0; ??? On RPI I try for an equivalent by: memset(&rx, 0, HDR_SIZE); rcvdc = 0; -- Tomas Kral <thomas.kral at email.cz>