Subject: Re: ADB port/game
From: [email-masked] (RUBYWAND)
Date: 28 Jun 1996 18:47:38 -0400
Newsgroups: comp.sys.apple2

In article <[email-masked]>,
Sedgwick <[email-masked]> writes:

>
>Can you post how to make these converters. I have a good PC stick siting 
>on my desk right now that I would love to use.
>

     Okay. The following is condensed from an article in the Spring issue
of II Alive:

         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 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

     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) Game Stick and 'normal' (full swing) Graphics Stick.

Rubywand