public void handler() {
            int i;

            sys16_onetime_init_machine.handler();

            /* invert the graphics bits on the tiles */
            for (i = 0; i < 0x60000; i++) {
                memory_region(REGION_GFX1).write(i, memory_region(REGION_GFX1).read(i) ^ 0xff);
            }
            sys16_sprite_decode(3, 0x80000);
        }