public void handler() {
            sys16_bg1_trans = 0;
            sys16_rowscroll_scroll = 0;
            sys18_splittab_bg_x = null;
            sys18_splittab_bg_y = null;
            sys18_splittab_fg_x = null;
            sys18_splittab_fg_y = null;

            sys16_quartet_title_kludge = 0;

            sys16_custom_irq = null;

            sys16_MaxShadowColors = NumOfShadowColors;

        }