Trak-Ball Atari 2600 Trak-Ball Games

[BigO]

I think Millipede and Centipede play well in both modes. Anyway, all the ST Mouse versions seem to have a slightly more precise control at low speed than their cx22 couterparts.

Agreed. I will choose to use that STMouse mode whenever I have the option.

 

The guys have proven that they're able to poll the bits fast enough to catch practically every state change from the straight quadrature encoded signals.

 

Unfortunately, they will only be able to do so much with the CX22 because it reports half the transitions of the ST Mouse mode for equivalent hardware. I proved that their software changes would be fast enough to detect twice the number of state changes with the CX22 encoding scheme if they were there.

 

So, it appears to me that the tweaking of the CX-22 software to gain quicker movement will be a compromise to make up for the lower resolution of the CX-22 hardware. They can move the player further per detected state change, but at some point that movement will look "jerky".

 

I never played any real arcade trackball games, but my recollection of seeing them included a fairly significant amount of ball spinning. If the goal is an arcade experience, we may be pushing in the wrong direction. Any arcade experts care to weigh in on that?

 

I really like the way Colony 7 ST Mouse version plays, so I'd hate to lose that.

 

My standard disclaimer: I don't have any "real", standard hardware.

[BigO]

Arcade Centipede being played.

[Omegamatrix]

Another issue that can cause jerkiness at slow speeds is the user thinking they are travelling perfectly on axis when in reality they may be hovering back and forth on the edge. I'm sure it's already been noted how much physical movement is needed to have a change of state for a CX22 trak-ball. What I'm wondering is if the movement threshold is well below any particular disturbances caused by dirty trak-balls.

 

 

I don't like to feel disturbances in the force.

[Omegamatrix]

I think Millipede and Centipede play well in both modes. Anyway, all the ST Mouse versions seem to have a slightly more precise control at low speed than their cx22 couterparts.

Well, at least it's not jerky. The ST Mouse will always have more control at slow speeds due to more pulses. Ultimately the way to get better control is to extend the range of the CX-22 samples while keeping ST Mouse and Amiga Mouse the same. Unfortunately it is only reasonable to sample during the kernel and I'm already at max for Millipede. But if I could sample over another 60-80 lines I think it would be enough to be very controllable at low speeds.

 

 

Alternately you can double output like Thomas did, or maybe do some staggering with look up tables. I think the staggering would feel worse then simply using a scalar.

[Thomas Jentzsch]

So where are we now?

ST (aka CX80) and Amiga mouse versions seem to work well, but CX22 they seems too slow in some games. It feels a bit jerky which becomes worse when we double the response speed. I could try to add a few extra polls, but I doubt this will be a significant improvement.

Here are some thoughts:

1. we double the speed in Colony 7 and MC, but leave it as it is in Reactor, Centipede and Millipede.
2. instead of doubling, we go by a factor of e.g. 1.5
3. after doubling, we reduce the result by 1. This would allow single pixel movement.
4. more ideas...?

[Omegamatrix]

The force will be with us always soon. Late this weekend if all goes well. By Dec 18th for sure.

[BigO]

The force will be with us always soon. Late this weekend if all goes well. By Dec 18th for sure.

Does that mean you're working on updates?

I'm looking at an option for getting my hands on some stock trackball hardware that needs repair work. Just not sure I want to pull the trigger on another project right now.

[Lynxpro]

 

So where are we now?

 

ST (aka CX80) and Amiga mouse versions seem to work well, but CX22 they seems too slow in some games. It feels a bit jerky which becomes worse when we double the response speed. I could try to add a few extra polls, but I doubt this will be a significant improvement.

 

Here are some thoughts:

1. we double the speed in Colony 7 and MC, but leave it as it is in Reactor, Centipede and Millipede.
2. instead of doubling, we go by a factor of e.g. 1.5
3. after doubling, we reduce the result by 1. This would allow single pixel movement.
4. more ideas...?

 

 

What about adjusting the speed with difficulty switches or some other scheme?

[Omegamatrix]

Does that mean you're working on updates?

Yes, with some Jedi mind tricks.

[BigO]

Had the Trak-Ball opened up on the bench refining some things for a while, but got it back together this afternoon.

I can play with the ROM's that just came in from a galaxy far, far away.

[Lynxpro]

Had the Trak-Ball opened up on the bench refining some things for a while, but got it back together this afternoon.

I can play with the ROM's that just came in from a galaxy far, far away.

 

You're playing Jedi Arena with the Trak-Ball? Well, why not…you can play 5200 Super Breakout and Tempest with its Trak-Ball.

[Omegamatrix]

The Force Has Awaken!!!

 

 

Well, not quite yet young Jedi's..... but there is now an arcade game attached to the first post from a long, long time ago.

 

 

Enjoy.

[BigO]

 

You're playing Jedi Arena with the Trak-Ball? Well, why not…you can play 5200 Super Breakout and Tempest with its Trak-Ball.

It's not Jedi Arena. But, the scenario is even weirder than you suggest. This 2600 game I'm playing is being played with a 5200 Trak-Ball*.

 

*Some minor modifications required.

Edited December 14, 2015 by BigO

[Andromeda Stardust]

The Force Has Awaken!!!

 

 

Well, not quite yet young Jedi's..... but there is now an arcade game attached to the first post from a long, long time ago.

 

 

Enjoy.

Nice! More games...

[Thomas Jentzsch]

Question: Has anyone played the CX80 encoded hacks with a ST mouse? Or did anyone have a problem when playing with a CX80 encoded Trak-Ball?

 

The reason I am asking: There is a discussion going on, that the X and Y axis are reversed between ST mouse and CX80. So you would have to turn one of the two controllers by 90°.

[Omegamatrix]

Where is the discussion?

[Thomas Jentzsch]

Not on AtariAge, private mails with someone who is doing a C64 project.

[funknflow5200]

The Force Has Awaken!!!

 

 

Well, not quite yet young Jedi's..... but there is now an arcade game attached to the first post from a long, long time ago.

 

 

Enjoy.

yes!! thanks so much! will try tomorrow.

[alex_79]

Question: Has anyone played the CX80 encoded hacks with a ST mouse? Or did anyone have a problem when playing with a CX80 encoded Trak-Ball?

 

The reason I am asking: There is a discussion going on, that the X and Y axis are reversed between ST mouse and CX80. So you would have to turn one of the two controllers by 90°.

 

There are schematics for ST mouse and dual-mode Amiga/St mouse on-line. In all of them X axis is on pins 1-2 and Y axis on pins 3-4, which is the same pinout assumed in the hacks. Many later games for the 8-bit computer line are compatible with the ST mouse, so It makes sense that Atari modified the later produced cx80 trackball to adopt this scheme, while it is highly unlikely that they would have used a third pinout incompatible with the two estabilished standards (cx22 trackball and St mouse) and which wasn't supported by any existing software.

If a trackball with inverted-axis ST encoding exists, it's most probably an home made hack. Maybe the original owner hacked the trackball with 2 independent buttons and reversed the axis so that he could use both buttons with one hand by rotating the controller 90 degrees...

 

[alex_79]

By the way, apart for the very old posts by Eckhard Stolberg in the stella mailing list (see here), I've found no other mention of cx80 trackball with (presumibly) factory installed ST mouse encoding. Could those have been the results of a modification made by a local distributor instead of Atari itself? There are several aricles on late '80s, early '90s mailing lists or magazines explaining how to turn Atari trackball into Amiga or ST mice and I found a few pictures of home-modified ones (but it was clear by the pictures that the mod was home-made and in those cases the joystick-mode functionality wasn't preserved). If anyone reading this thread has a cx80 trackball with working TB-JS switch that behaves like a ST mouse, and can post detailed pictures of the pcb board, it would be really appreciated.

[alex_79]

I found other pictures of modded cx80 trackball on this page:
http://www.simulationsraum.de/blog/2012/03/07/entering-the-80/

They are a bit blurry and low in resolution, but they seem to match the description given in the stella list posts mentioned above.

[...] I have bought a VCS trak-ball from a ST computer store and it was in the bin for used ST mice. I can move the cursor in Stell-A-Sketch with it when I use the ST-mouse controler setting, but only the left button works. So it might be possible that the trak-ball was modified in the store to be compatible with the ST mouse. Or do all trak-balls behave like this? [...]

[...] I have opened up the trak-ball and had a quick look at the board. I'm no electronic expert, but the board didn't look modified to me. There were two wires soldered between two of the chips, but since it was a REV-A board, I suppose that's normal. [...]

Here are the differences between the cx80 in those pictures and the standard one (I had to guess some of them, beacuse of the low quality of the image):

A jumper from 4019 pin 15 to 4013 pin 3

B jumper from 4019 pin 4 to 4013 pin 11

C difficult to say from the pic, but it seems that the board has been scratched to break some of the traces. My guess is that broken traces are those between 4019 pins 15-5 and 1-4, which are in that area of the board.

D My guess is that connection between pads 1 and 2 is cut and a jumper between 1 and 3 is installed instead. This cannot be actually seen from the images, but it just makes sense to me.

 

E on the component side a jumper is replaced by a resistor (This would became the pullup for the left button and I guess the value is 4k7 like the one for the right one, but I cannot tell from the picture)

F additional wire installed to have two independent buttons (This means that the original cable has been replaced, as it only had 7 wires).

In this rough drawing you can see those modification applied to the cx80 schematic. In this configuration the joystick mode is preserved, while the trackball mode is now sending ST-mouse encoding and there are two independent buttons.

[Omegamatrix]

I just added a Version 2 of SW Arcade to the first post. This has a bit smoother positioning at very low speeds thanks to an idea by Thomas Jentzsch.

[Thomas Jentzsch]

I have added new CX22 versions (v1.3) with double speed and smooth positioning for Missile Command, too.

[alex_79]

I just added a Version 2 of SW Arcade to the first post. This has a bit smoother positioning at very low speeds thanks to an idea by Thomas Jentzsch.

It was good already, but the new version definitely improved the control. Good job!

 

I mentioned before on PM that the ST version feels a little slower to me when moving on the vertical axis compared to the cx22. Now I did some more tests and my impression is confirmed, but only when moving upwards. In fact if you spin the trak-ball slow enough, the cursor doesn't move up at all, while you are always able to move down (and on the X axis) no matter how slow you spin.

I didn't test the Amiga version , because currently my trackball can work in ST or cx22 mode, but I can build an adapter if needed.

You can somewhat see this also in Stella, altough sensitivity when using the mouse seems higher than on real hardware, so you have to move very slowly.

 

Finally, I think that difficulty should be increased a bit: the other day I played up to over 500000 points (using the older cx22 version) and I still had all the shields, so I think I could quite easily roll the score if I have enough time (And I'm not a very good player in general). Don't know if it's doable, but maybe you could eliminate the bonus shields after you reach a certain score (or reduce them gradually).

 

[Thomas Jentzsch]

Agreed. Its a bit like in Colony 7, where the slow joystick controls originally where part of the challenge. With this removed, the games become a bit too easy.

 

Others like Millipede, Centipede, Missile Command allow for higher scores but IMO remain difficult enough. And Challenge of Nexar becomes playable at all in higher levels.