Re: Joystick buttons: normally "open" vs "closed"?

[Rubywand <rubywand@swbell.net>]

stephen e buggie writes ...
> 
> I have a joystick in good condition that came from a different platform.
> 
> I want to add a db-9 cable to make it usable with A2.
> 
> QUESTION: Are the two "firing buttons in an Apple joystick normally "closed" or
> "open"?
>

     They are normally "open" (not closed, etc.). The following details
may be helpful ...

     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



Rubywand