Re: Kraft Joystick Question!

[rubywand@aol.com (RUBYWAND)]

In article <50k5e7$l44@News.Dal.Ca>, tony@ccn.cs.dal.ca (Tony
Cianfaglione) writes:

>
>   I picked up a used Kraft joystick in good shape that looks identical
to 
>the one I use for my IIc at a yard sale for a couple of bucks.  It has
the 
>adjustable pots for fine-tuning the joystick as well as the centering 
>defeat switches on the bottom.
>
>   However, it has a Db15 pin male plug instead of the usual 9 pin male 
>plug.  I know it's not for Commodore, Amiga or Atari as they use the 9
pin 
>female plug. 
>
>   Is it IBM?  Is there an adapter to use it with a II?
>
>

     It is, probably, an IBM stick.

     Epyx did market an "adaptor"; but, it was _only_ for their Apple2/PC
joysticks; and, it 'converted' from Apple2 to PC. (The Epyx stick used a
special diode network so that it could work on either system. Their
adaptor just handled the plug conversion.)

     Unfortunately, diode switching is not satisfactory for a stick you
want to work for all applications. (The diodes tend to clip the
resistances a stick's pots can output.)  There is no super-easy 'trick'
for making a PC stick work like an Apple2 stick. 

     So far as I know, no one has ever produced a commercial PC-to-Apple
joystick converter that works for a typical, high-quality, PC stick (like
FlightStick, your Kraft, etc.).  However, directions for building a
PC-to-Apple joystick converter were published in Spring II Alive. A
condensed version of the directions is presented below:  



         To PC Stick                             To Apple II
(15-pin female connector)             (9-pin male connector)

         [1] [4] and [5] --------------------------- [2]  +5V
         [2] --------------------------------------------[7]  Button 0
         [3] --------------------------------------------[5]  X-axis
         [6] --------------------------------------------[8]  Y-axis
         [7] --------------------------------------------[1]  Button 1
                                                          [3]  Ground

     On the 9-pin Apple II side ...
        add 680 Ohm resistor between [7] & [3]
        add 680 Ohm resistor between [1] & [3]
        add .01 uF cap between [5] & [3]*
        optional: add 50K-100K trim pot in series with the cap
        add .01 uF cap between [8] & [3]*
        optional: add 50K-100K trim pot in series with the cap

*NOTE: The Capacitors compensate for smaller R range of PC
 sticks.The C values are approximate. For standard 100K Ohm
 PC sticks, .01 uF pretty well guarantees you will be able to
 cover the full Apple II X and Y range (0-255).

 Values of .01 uf  (X-axis)  and .005 uF (Y-axis)  worked
 well on the PC "FlightStick" when plugged into our Apple II+.

     Most likely, you will find that the a stick tops-out too early
in the X-max and/or Y-max direction. For best control precision,
what you want is for extreme values to occur near the extremes
of stick movement:

X (horizontal)  Left= 0   Right= 255
Y (vertical)      Up= 0    Down= 255

This way, you have lots of active swing which makes graphics
work and playing most games much easier. 

     For adjusting, use a program which continuously reads and
displays X and Y stick values. The program below does this and
displays "B0" when Button 0 is pushed and "B1" when Button 1
is pushed. Do a CTRL-C to exit.

20 PRINT "X= "; PDL(0); TAB(15); "Y= ";PDL(1); TAB(30);
30 IF PEEK(49249)>127 THEN PRINT "  B0";
40 IF PEEK(49250)>127 THEN PRINT "  B1";
50 PRINT: GOTO 20


     Experiment with capacitance values between .002 uF
and .01 uF to get the best 'spread'.  For easier fine-tuning,
add the 50K-100K trim pots in series with each capacitor.

     The converter I built fit inside heat-shrink tubing. Putting it
in a small plastic box may be better. You can mount the
trim pots (and/or switches with fixed "trim resistors") and
select between settings for a 'Fast', short swing, 'hot' Game
Stick and a 'Normal', full swing, 'cool' Game/Graphics Stick.
     

Rubywand