As you probably already know, Spectrum models equipped with joystick ports, are unfortunately not compatible, with the vast majority of 9pin Joysticks/Gamepads manufactured, which used the Atari standard, followed by many successful Home Micros of the era (like Amiga, Atari, Atari ST, C64, Amstrad CPC etc).
So, bellow i present you a schematic for making an adapter that will allow you to use all of these joytsicks/gamepads directly to your Spectrum:
As you can see, it's rather easy to do it , you will only need a male & female 9pin D connector, and a small piece of multi strand cable or even a ribbon cable, to make the connections between the pins:
Anyone interested, please contact at: ikonsgr745@hotmail.com