Re: game i/o - joystick adaptor

[Rubywand <rubywand@swbell.net>]

Sagochangi writes ...
> 
> >     The IIgs on-motherboard 16-pin Game Port supports two complete
> >two-button sticks. The ][, ][+, and IIe on-motherboard 16-pin Game Port
> >comes close but does not include the 4th button. The //c series (9-pin
> >Game Port) supports just one two-button stick and will accept a mouse.
> 
> Well, the PC Gamepad is a four-button joystick, which is why I asked. Couldn't
> the 16-pin DIP socket be made to work for a 4-button joystick, like the
> Gamepad?  That would be really great, esp. for use with new games like the
> Super Mario port (start, select, A, B), if the programmers would support it.
>

     Yes; the IIgs Game Port could handle the 4-button stick via the 16-pin socket. The adapter described below should work.


  To PC Stick               to 16-pin IC plug
  15-pin Dsub               ribbon cable to IIgs
  female connector          internal Game socket

      [1] [4] and [5] --------- [ 1] +5V
      [2] --------------------- [ 2] Button 0
      [3] --------------------- [ 6] X-axis PDL0
      [6] --------------------- [10] Y-axis PDL1
      [7] --------------------- [ 3] Button 1
                                [ 8] Ground 
     [10] --------------------- [ 4] Button 2
     [14] --------------------- [ 9] Button 3
     [11] --------------------- [ 7] alt x  PDL2-- optional control
     [13] --------------------- [11] alt y  PDL3-- optional control


On the 16-pin Apple II side ... 

  add 680 Ohm resistors between ...    [ 2] & [ 8]
                                       [ 3] & [ 8]
                                       [ 4] & [ 8]
                                       [ 9] & [ 8]


  add .01 uF caps between ...          [ 6] & [ 8] X
    Note: for fine-tuning,             [10] & [ 8] Y
    add 50K-100K trim pot              [ 7] & [ 8] Z      -- optional
    in series with each cap            [11] & [ 8] Thrust -- optional

 ....

> 
> Okay, would the PEEKs for the two new buttons be PEEK(49251) and PEEK(49252)?
>

     Close. The IIgs uses the old Cassette-In address for PB3. So, the addresses for the two new switches are ...

PB2- 49251
PB3- 49248


     The odds are pretty good that your PC 4-button stick would work fine with current A2 games. You would just need to use the one or two buttons the game recognizes.

     I do not know of any single-player A2 game which uses more than two buttons. However, the adaptor would allow plugging in PC sticks with up two four buttons and two aux controls. Maybe someone will mod an old game or create a new one which can use a fancy stick.


Rubywand