Re: Apple Joystick adapter for IBM port available? How to make?

[rubywand@aol.com]

In article <32f87b85.1846351@news.minn.net>, ttec@minn.net (Greg) writes:

>
>I have an apple //c joystick and was wondering if anyone out there has
>made a cable/adapter to use it with an IBM joystick port.
>
>

The following should help ...


Apple2-to-PC Joystick Conversion  12/96 version
     to A2-WUG,1wsw, GS.WorldView


     Below are pin-outs and info for Apple II and PC joysticks. As you can
see, there are three major points of difference:

1. The Apple II stick uses a 9-pin plug vs. the PC's 15-pin plug. (Older
Apple II sticks may use a 16-pin plug which fits in an IC socket.)

2. The Apple II stick's X, Y controller potentiometers are a bit larger.

3. The buttons are wired differently.


     You can use an Apple-to-PC adaptor (such as the one supplied with the
Epyx A2/PC joystick) to handle plug conversion; or, you can replace the
entire cable with one from an old PC stick.

     The PC joystick interface will work with the Apple2 150k pots; but,
in some applications, you may notice a tendency to max out early in the
stick swing. You can correct this by connecting a 300k resistor across
each pot (from the center to the end with a wire going to it).  

     The difference in button wiring is the main reason an Apple-to-PC
conversion involves opening the joystick and making changes. (The Apple
stick has a slightly more complex, less flexible circuit. Apple-to-PC is
not as easy as PC-to-Apple.)

     Basically, you need to change the Apple stick's button wiring so that
it looks like the PC stick's button wiring.

     The mods mentioned above are not difficult, especially if you swap in
a PC cable. If you want to be able to use the stick on an Apple II, then
some kind of switching will be required.  



         Apple II Joystick
     (9-pin male connector)         (Old 16-pin IC-style plug)

         [2]---------------  +5V             ------- 1
         [7]---------------  Button 0       ------- 2
         [5]---------------  X-axis          ------- 6
         [8]---------------  Y-axis         ------- 10
         [1]---------------  Button 1      ------- 3
         [3]---------------  Ground        ------  8



         PC Joystick 
 (15-pin female connector) 

         [1]---------------  +5V
         [2] -------------- Button 0
         [3] -------------- X-axis
         [6] -------------- Y-axis
         [7] -------------- Button 1
         [4] and/or [5] Ground


     Both sticks tie one end of each X, Y potentiometer to +5 and send the
center (wiper)  to the an output. The standard Apple II pot is 150K Ohms;
most PC sticks use 100k Ohm pots.

     The buttons are wired differently.


APPLE ][

     On the Apple II stick (see below), each button switch goes to +5V.
The other end goes to GND through a resistor (one resistor for each
button).  A button's Output is from the junction of the switch and its
resistor. When the button switch is not closed, its Output is near 0V
(=logic 0).  Pressing a button sends +5V to the output (= logic 1).

+5V
|
|
X Button Switch
|
|_____Button output to Apple (Press => "1")
|
Z
Z 680 Ohm resistor
Z
|
GND



PC

     As shown below, a PC stick button Output is normally an unconnected
wire. Most likely, inside the computer, a PC or compatible Game Port has
this line tied to a 1k-3k resistor going to +5V. So, the line will
normally be at something close to +5V (= logic 1).  Pressing the button
grounds the line and pulls it down near to 0V (= logic 0).

_____Button output to PC (Press => "0")
|
|
X Button Switch
|
|
GND


Rubywand