Trackball controllers

[PAH]

I'm just getting started with 2600 programming, and figured hacking a game or two to use the trackball controller would be a good start. I see that Thomas Jentzsch has already hacked Missile Command for the trackball, so if nobody else is working on Millipede and/or Centipede, I figure I'll tackle them.

 

That said, I realize there are two models of trackballs out there, the cx-80 and cx-22. What are the differences between these? There is no number on my trackball, so I'm not sure which one I have.

 

Also, can anyone point me to some info on how the trackballs behave from a software point of view - i.e. which bits do what when you move the ball this way or that way?

 

Thanks,

 

Pete

[Thomas Jentzsch]

Well, implementing the Trakball into other games is not as easy as it might look like.

 

Since the Trakball has a very high resolution, you have to check the values very frequently. The only way here is doing this inside the display kernel. Since this requires some extra time, only games with very simple kernels (with free CPU time) will work here. And since Centipede/Millipede have a quite complicated kernel, I am afraid your idea won't work.

[Zach]

You know, I've been wondering if Centipede/Millipede TB could be pulled off with flickering? That is, read the trackball in one frame and draw the kernel in the next.

[Zach]

By the way:

Also, can anyone point me to some info on how the trackballs behave from a software point of view - i.e. which bits do what when you move the ball this way or that way?

 

If I were you, I'd search the Stella list, and also disassemble Thomas' Missile Command TB and compare it to a disassembly of the original.

 

Here's a good link to start with:

http://www.biglist.com/lists/stella/archiv...0/msg00472.html

 

By the way #2:

Even if Centipede/Millipede won't work. I always thought Othello TB would be fun. It may even be feasible.

[Zach]

OK. I answered my own question about Centipede with flickering by reading the link above.

 

You need about 20 reads per frame to get a good

control over the cursor. Doing it only once per frame

would only result in jerky movement, as you would never be

able to read the next value of the code sequence.

 

So when Thomas said "very frequently", he meant more than once per two frames.

[PAH]

Thanks for the feedback. I guess I should have thought of the resolution issue and clearly centipede/millipede have busy kernels.

[tony clifton]

you all sound like a bunch of hacks so you probably all belong to hang out here. I will not though because you smell like a bunch a wrestlers

[Thomas Jentzsch]

And I smell a troll.

[uosipa llamxew]

And I smell a troll.

Yup... four posts, and each are equally ridiculous.

For a long time I actually thought that the "ignore" feature was an unnecessary feature in this forum. In the last month I've added three members to my list. :-P

[tony clifton]

I am tony clifton! show some respect you dirtballs or go play your new game man going down on wrester

[Inky]

I am tony clifton!  show some respect you dirtballs or go play your new game man going down on wrester

 

Forget about checking out for the first sign of intelligence from this troll.