5200 joystick with Popeye

[Oldschool80skid]

Hello,

I could not find any topics regarding this issue. When I play Popeye only, the Atari CX52 will not go down in any direction. However, it works perfectly fine with Digdug, Pacman, Ms. Pacman, Qbert, Kangaroo, and Bezerk. My other CX52 functions normally with Popeye. I have cleaned the connectors on both of the pots. Does anyone have any ideas on why this could be happening with only one game? I am curious if it could be somehow related to the wire harness.

Thanks,

Tom

[Charlie_]

Never mind, didn't read your post fully............

 

The CX52 that has trouble going down probably just needs the vertical pot tuned a bit.

With the controller open move the pot to see what direction is up and down.

Since it has trouble with down, you want to gently force the arm on the pot just so slightly past where it stops it's swing in the UP direction.

Edited July 17, 2014 by Official Ninja

[Hyperboy]

"has trouble going down"

Sounds like a girl I dated in high school!

Edited July 17, 2014 by Hyperboy

[+Cafeman]

I noticed Popeye 5200 was problematic with my stock 5200 controllers too, in this way. I've opened up the controllers but after a while, I just use my Masterplay with a digital stick for Popeye.

[BigO]

I had built an analog 5200 controller, using the fairly common "additional capacitor" method. I don't recall the details, but Popeye was one game I had trouble with. I didn't have any working stock controllers so I thought it was a limitation of my controller. It's a good share of the reason I didn't make any more of those controllers.

 

The fact that a digital controller works is interesting. It must be supplying a resistance at an extreme that isn't easily reached by the stock controller.

 

I vaguely recall analyzing the signal with an oscilloscope and finding that the hardware was discharging the capacitor much more frequently than other games. I came to the conclusion that the circuitry couldn't sink enough current to discharge my extra capacitance quickly enough. Not 100% sure, but fairly certain it was Popeye that I analyzed this way...

[bohoki]

i too noticed popeye has a very high trigger value there is the internal calibrator you may be able to adjust do he can go down the ladder

[Gabriel]

In other posts I've learned that some games like Ms. Pac Man have code which adapts the movement values to what your stick put out. So when you push all the way left, the game registers that as it's left boundary. When you press all the way right, the game registers that as it's right boundary and so on. From the values learned the game calculates the center of the controller and an out of alignment 5200 controller or system can still be used to play those games.

 

Not all games do this. Some games seem to use fixed values with no adaptability to determine left, right, up, and down. I know Congo Bongo is like this. I think Popeye is too. There are two solutions for these games.

 

One solution is to adjust the controller. 5200 controllers get out of alignment sometimes. When this happens they need to be taken apart and the pots inside realigned.

 

Another option is to adjust the Pokey pot in the system. This actually will change the ranges the controllers will produce. For example, a controller may not be physically capable anymore of generating a vertical value of 200 or higher. By adjusting the Pokey you skew the controller pot's center so that higher values can be produced. The trade off is that you may have just created a situation where games like Popeye ALWAYS register down instead of never registering the direction. When I've done this I've always had to use a diagnostic rom image to fiddle with it using different controllers to test. Missile Command is an excellent test cart for this kind of tinkering.

 

Incidentally, adjusting the Pokey NEVER does anything with regards to the trackball, only the controllers.

 

This is all definitely my layman's understanding. If I've mangled something in my explanation, I didn't mean to.