Re: I need JOYSTICK info, thanks!

[yakumo@u.washington.edu (Christopher Thomas)]

In article <2qot0l$8hc@crl.crl.com>, Warren Ernst <wernst@crl.com> wrote:
>jeff alan blaize <jblaize@silver.ucs.indiana.edu> writes:
>
>>	I have an Apple Joystick ][e from 1984 or something.  It has a nine
>>(9) pin male connector to plug into the back of some apple.
>
>>	What I need is to know the specs of the nine pins.  I need to know 
>>what pin does what on this joystick.
>
>>	WHY?  Well I am going to attempt to convert the joystick for use with
>>an IBM-compatible game IO port.  I don't know if I this is even POSSIBLE but
>>I have the tools and I want to try.
>
>Jeff,
>
... Pinout info deleted...
>
>The probelm here, once you cros 9 impossibly tiny wires, strip them 
>and solder them, you have a joystick where the buttons are opposite! On 
>an apple, the button switch is normally closed. On a PC, the button 
>switch is normally open. (or vice versa, I forget now - my notes are at 
>home). As I was working this out, it seemed that the buttons would be 
>wired in series on one machine, but not on the other. Therefore, you 
>would have to replace the buttons, which aren't cheap (I REALLY looked 
>for some that would last and be comfy), and then work out teh wiring.
>

I tackled this problem myself a while ago.  I don't know the specs of
the 9-pin configuration (I owned a ][+), but I solved the inverted
button problem by going down to my local Radio Shack and buying a chip
called a 'hex inverter'.  Put the 5V power into the power supply pin
on the chip.  There are about 6 pairs of pins on the chip.  Each pair
is connected to a NOT circuit.  If you put this circuit in series with
a button, the button will perform to IBM specs.

I think there is another slight incompatibility here: I heard that IBM
joysticks run on 100K ohm pots.  Apple joysticks use 150K pots.  If
you put a 300K resistor in parallel with each pot on the joystick, it
should put the total resistance into the right range for an IBM (you
shouldn't take my word for it: I did it on a cocktail napkin).  I'm
working on this mod, but haven't finished it, so I couldn't tell you
if it will work, but it should in theory :)

I hope this helps

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