Joystick

[Martin Doherty <martin.doherty@undisclosed.com>]

I picked up an Apple Joystick //e from eBay, no manual.  Right now it's 
spring-loaded (auto centering), which is fine for games. I have two 
questions, probably related:

1) On the underside, there are two thumbwheels and four plastic screw 
adjusters.  What do they do?

2) Is there a mode for using the joystick in a kind of floating mode 
i.e. not auto centering? (Suitable for drawing graphics)

Here's the underside layout:

    |||||||||||||                     <-- Y thumbwheel

([])              ([])                <-- Y2/Y1 screw adjusters
 ^                 ^
 Y2  JOYSTICK //e  Y1
                     X1>  ([])  _     <-- X1 screw adjuster
                                _
                                _
                                _
                                _     <-- X thumbwheel
                                _
                                _
                                _
                     X2>  ([])        <-- X2 screw adjuster


As per this diagram, all 4 screws are currently aligned with a 
north/south groove.  When I tried messing around with these controls it 
just seemed to bugger up the joystick's movement.

Martin