New CX80 Trak ball does not work

[cvdh1983]

Hello

I recently bought a new in box old stock unused CX80 Trak ball to use with the Atari Age TB series. It doesn't work in TB mode, only in JS mode on other regular 2600 games. What happens is that, at the beginning of the game, it cycles throught the game variations, the variation number on the title screen changes on its own. Graphics glitch, I can't play the game and then it freezes with horizontal stripes.

I can return the trak ball. There are two other NIB ones on Ebay but I'm a bit paranoid now that they will be from the same faulty supply.

Has anybody experienced this? Is anybody willing to repair this? I would be so grateful

[mr_me]

What are you testing trackball mode with exactly? There are no original atari 2600 cartridges that support trackball mode.

[mr_me]

My understanding is that there's also a variation of the cx80 that makes it compatible with the atari st mouse and not compatible with 8-bit trakball games.

[BigO]

The description sounds like what would happen if you're using TB mode on a game that wasn't built for trackball input.

 

The trackball output uses the same pins as a joystick. But, when you're rotating a trackball like this one in TB mode, one pin (per axis) toggles between on and off depending on the direction being rolled and the other pin on that axis toggles between on and off as the ball rolls a given amount so that the game can see how fast/far the ball is rolling.

 

(The above described motion encoding scheme is commonly referred to as "Up/Down Clock". Other trackballs may output a count sequence known as "Gray Code", from which can be decoded direction and speed/distance the ball is rolled. This can provide greater resolution than Up/Down Clock but is a bit more complex to interpret.)

 

In TB mode, pins are turned on and off in patterns that won't be meaningful to joystick game software. In addition to the signals not representing the 4 cardinal directions, the TB mode will set both pins of an axis to active at the same time which is an "impossible" condition for a joystick to produce. How a particular joystick game handles that condition would just be a side effect of how that game program was written.

 

It doesn't really sound definitively like your trackball is defective, unless you're actually testing TB mode with a game specifically built to be compatible the signals output in TB mode. You didn't clearly say this, which leads me to infer that you are testing TB mode using a joystick only game. If that's not the case then it's still possible that your trackball is defective.

[+Nezgar]

I know the CX-22 has a switch to toggle between true trakball mode and joystick emulation. I don't have one, but supposedly the CX-80 has such a switch as well.