Ah, the WHDLoad works, that's good
The new method should work for many more releases.
The split control idea came to me one morning, and by chance later that day Garry suggested something very similar to me.
Yes it makes use of the parallel port adapter (very easy to get hold of or make!). Just adding a new dimension to tournament fun, especially when beer is involved. When the ball crosses the halfway line, control automatically switches to your teammate's joystick. So you can have a 2v2 game or 2vCPU game where you work together or just scream at each other in order to get the goals.
Obviously KO2 already had a 4 player mode, but it was tied to the play-in-position feature, where you ended up spending 80% of the time hoping that the AI would send the ball your way.