If you're wondering whether your old 9-pin joysticks are still functional, there's an easy way to check without the need to turn on your C64. All you need to do is insert a CR2032 button cell into the device, and then connect it to the joystick using the 9-pin D-Sub connector. Once you've connected the joystick, move it in all directions and press the fire button. If everything is working properly, the corresponding LEDs on the device will light up, indicating that your joystick is fully functional and ready for use. This method is not only convenient but also efficient, allowing you to quickly and easily test your joysticks without the need for additional equipment or a working C64. So why not give it a try and ensure that your old joysticks are still in good working condition, ready for hours of gaming fun?