Joystick port Atari 600XL

[Martin72]

Today, i had a problem with my Atari 600XL. I want to play a game and the forward direction of the joystick doesn't work. I have immediately repaired the Atari (replacing the PIA 6520) and the joystick works fine.

I see there's a difference in the schematic of the 600XL and 800XL. For example: in the 600XL from PA0 (pin 2 of U21) there's a capacitor (1 nF) to connector J6, the joystick connector. In the 800XL i see at the same place a resistor of 220 ohm to the joystick connector with a capacitor of 1nF to ground. Does somebody know why they introduced this difference? And is the solution they aplied to the 600XL is a bad solution? Could it be possible the PIA is dead by this solution?

[Beetle]

They did it to save up space inside the stuffed 600XL, and it is of course not a good idea.

Any accidental shorting (for example touching the joyport pins with a fingers ring) can result in

immediate damage like yours.

 

Anyway, if you use it with care, simple usage with Joystick won't damage anything.

[Martin72]

Ok, thank you. I think i will make a modification in the 600xl because i like to use the joystick ports also for other things and it is more safe.