A nonvolatile storage cell and an integrated circuit including the cells. An exemplary pushpin retaining device can include a resilient, elongated pin that can have a first end portion for puncturing and a second end portion. In order to prevent different pressure loads between the accumulator and the hydraulic cylinder, it is suggested to equalize the pressure between the accumulator and the hydraulic cylinder, without impairing the spring support system or the automatic shut-off valve. The lid also contains a hinged door having an opening connected to the frame.