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Re: A2 Joystick Maintenance
Polymorph wrote:
Polymorph wrote:
So thanks for your advices - I'll give the terminals a little solder
after doing another round of cleaning (with contact cleaner) to
*hopefully* remove any further WD-40 residue. I'll report my
success/failures tonight when I get home. ;-)
Well, after doing *heaps* more cleaning with contact cleaner and a
slight bit of manipulation of the pot internals (the sweeper?), I have
managed to get the old joystick functioning pretty well (and no
soldering was required). The erratic behaviour has gone completely,
however, I am still facing the problem whereby one of the pots only
gives a range of 0-225 (ie. using the applesoft joystick test). BTW,
this was the pot that I did not "manipulate" the internals of
(hmmm....maybe I should).
Is there any easy way of fixing this, or is this the problem of
linearity that you mentioned is hard to fix?
No, a range of 0-255 is exactly what you should see from a device
whose output is represented as a single 8-bit byte. ;-) The Apple
will respond to any resistance greater than a certain value (near 150K)
with a time measurement of 255.
That means that you are getting the full range of resistance (and maybe
a bit more, since 255 is probably reached before the stick reaches the
end of its travel).
I imagine most games would function OK with this range, however, the
game I tested it with (Sensei) did not respond to downward movements
(ie. moving the stick in the limited 0-225 axis). I read that you can
counter this when converting an IBM style joystick by introducing a
capacitor to increase the resistance somehow. Would it be possible to
do something similar here to increase the range?
What you describe is a centering problem, not a range problem.
Any value below 128 (or so) (or above, depending on which way the game
expects the stick to work) will represent "down", just as the opposite
side of 128 will represent "up".
-michael
New, faster SUDOKU v2.0 solver for Apple II's!
Home page: http://members.aol.com/MJMahon/
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