Several games on the Jaguar are more fun to play if you have a rotary controller (there's Tempest 2000 of course, but also Kobayashi Maru by Reboot for example). Here's a little tutorial to build one from a standard Jaguar controller, without losing the ability to use the D-pad for "normal" games.
What you need :
- a standard Jaguar controller, obviously
- a mechanical encoder, preferably without detents (i.e. that rotates freely without "clicks"). The number of steps per revolution will determine how sensitive the knob is ; 24 to 36 steps is fine.
- a knob to put on top of the encoder
- a DPDT switch. It will be used to switch between "normal" and "rotary" mode.
- some wires, a soldering iron with solder, some heatshrinking tubing if you want to be neat
The encoder, knob and DPDT switch are not very expensive ; I paid 5€ (about $6.50) for all three.
The first step is of course to take your controller apart. The screws are hidden under round, adhesive pieces of rubber ; lift them gently with a screwdriver.
Then pretty much everything you need to do is summed up in this picture :
Before closing the controller, check that everything is working fine. If the rotary part works backwards, swap the outputs of the encoder.
And this is how the result looks like :