[Linked Image from i.imgur.com]

The Sirius Joyport would plug into the 16 pin gameport socket in an Apple 2 and allow you to plug in two Atari 9 pin digital joysticks.

I just put in a hacky config thing so I could enable it/disable it, because if a program doesn't support the Joyport, you need to be able to switch back to the normal gameport behavior.