Found this with Google:
Apple Game Port (9-pin connector):
Dsub-9 Female Socket (on computer)
,---------------------.
\ 5 4 3 2 1 /
\ 9 8 7 6 /
`-----------------'
Pin 1 - Pushbutton 1
Pin 2 - +5V Power
Pin 3 - Ground
Pin 4 - Game Control 2 or PDL2 (Joystick-2 X-axis)*
Pin 5 - Game Control 0 or PDL0 (Joystick-1 X-axis)
Pin 6 - Pushbutton 2*
Pin 7 - Pushbutton 0 (usually the "Fire" button)
Pin 8 - Game Control 1 or PDL1 (Joystick-1 Y-axis)
Pin 9 - Game Control 3 or PDL3 (Joystick-2 Y-axis)*
Is there a way to do this if I don't know how to make cables? Are
there pre-made splitters for this?
erm maybe but they are not going to be cheap cause demand for them has
greatly gone down since the 80's
Why do you want to connect two analog joysticks? To play multiplayer
games or for something that you are developing yourself? If it is for
multiplayer Joyport games then you will need digital joysticks instead
(they use the annunciator pins on the 16 pin game port).
The only game that I am know of that supports two analog joysticks (on
the IIGS anyway) is Superstar Ice Hockey. I had planned to build an
adaptor to do this one day. Does anyone know how the pushbutton lines
are split between the two joysticks (my guess would be PB0 for either
button on Joystick 1 and PB1 for either button on Joystick 2)? Is the
third pushbutton (ie Pushbutton 2) used at all since it is only really
usable on the IIGS model?
Does anyone know why using two analog joysticks was not readily used?
I think I read somewhere that it would have made game play very slow.
If I can find out the best way to slit the pushbutton lines then I'll
make some up for sale.