Tempest 5200 - 30 Copies Available!

[+Cafeman]

Plug in your trakball and diagnostic cart. Go into POKEY test and tell me what value your trakballs are reporting as center. Should read 122 or close to that. When spinning it, the values should never be lower then 87 or higher then 166. I can try changing the range based on what you report.

 

I've never done this, but I'm interested in trying. I'll have to locate a diagnostic cart ROM and my Videogame Wiz RAM cart first.

[Dutchman2000]

The value I need is when the trakball is at rest. Then test the range and let me know the minimum and maximum values. Then I think I can adjust the range and see if that gives us better results.

[Charlie_]

I am sorry that you are having problems, our aim was to try and make Tempest the best we could. Remember we did this out of our spare time and the desire to get 5200 Tempest finished for all to enjoy.

 

There is no proper documentation on how to properly implement support for the trakball. We are not Atari, and do not have the resources they had. This is probably the reason why trakball support is absent from most homebrew efforts. What I found out worked for me and all the testers. If it does not happen for me or them there is no way for me to figure out what is happening. It is possible that the other Atari games use some kind of calibration technique to compensate for out-of-spec trakballs. We were not able to figure that out for Tempest, what we wrote worked well and there was no need to spend more time figuring it out.

Plug in your trakball and diagnostic cart. Go into POKEY test and tell me what value your trakballs are reporting as center. Should read 122 or close to that. When spinning it, the values should never be lower then 87 or higher then 166. I can try changing the range based on what you report.

 

Dutchman2000, it was never my intention to insult you. I have very high regard and respect for all of the home-brew authors out there. My appreciation for yours and others work on the 5200 is beyond describing.

 

I simply felt this issue should be looked at and taken seriously. It is very important and I happen to know many, including myself looked forward to the release of this project because of the trakball control. Its a perfect way to play Tempest short of an Arcade cab.

 

I am happy to have this dialog going with steps to get to the bottom of it!

 

I will get the reading from my trakballs tonight. I know that with a loopback plug is 112. Im suprised to see you suggest 122 as that is a lot higher. I know with the Masterplay, because of the resistors in it ,the number is slightly lower at 107. Still being a constant, it is a way to adjust short of the loopback plug.

 

Regardless, I will post my values tonight (after work) from 3 systems. I have AtariMax SD and USB carts to test if you would trust me to do so.

[Dutchman2000]

The center value of a joystick's HOR is 112, the trakball's is 122. The trakball has a much narrower range then the joystick, 87-166. The full range of the joystick is 0-228.

The fix may just be to widen the range a bit to compensate for trakballs that are a little off.

[Gabriel]

My trackball reads 103-104 x 106-107. Maximum horizonal range is 77 to 137.

 

If the vertical range is needed, then I'll get that value later.

[Charlie_]

My trackball reads 103-104 x 106-107. Maximum horizonal range is 77 to 137.

 

If the vertical range is needed, then I'll get that value later.

 

And are you having problems with tempest and your trakball?

[Gabriel]

And are you having problems with tempest and your trakball?

 

Yes. It constantly moves to the left.

[Dutchman2000]

This is good guys, post your HOR values. We don't use VER at all in Tempest.

[Charlie_]

This is good guys, post your HOR values. We don't use VER at all in Tempest.

 

Three Systems. Two Trakballs.

 

HOR values:

 

System 1 TB1: 111, 81-150 TB2: 110, 80-150

System 2 TB1: 105, 76-141 TB2: 105, 77-140

System 3 TB1: 112, 82-150 TB2: 111, 80-150

 

*Center seems close to that 112. I know system 2 needs adjustment, but it is not that far out and everything still works. It might be a good example of what you find out there in general because I just purchased that system from an AA member and haven't touched the adjustment. I did test it and saw it was a bit low, but was too lazy to open it.

If pitfall harry can climb up and down a ladder in Pitfall! (with a know correct controller) you pokey is close enough.

[TrekMD]

Mine arrived on Monday! Thank you very much! Now I'll wait to get another copy once it is on the store.

[+Cafeman]

The diagnostic cart won't load up on my 2-port. I use the original Videogamewiz A52 maxicart (flash cart) . Never had a problem with other ROMs. I noticed trying the diagnostic cart on A800win 4.0 that it is 2 8K chips as its setting. Anyway, I then got Pete's test cart to load up and it seems my trak-ball is very out of whack at a value of 189, 120-256 (actually it displays a 'symbol' which must mean "max value"). I just don't understand how it works on other games like Missile command and Centipede with these out-of-whack values.

 

How the heck do I adjust my trak-ball? I see no place, unlike the 5200 sticks where there are two adjustable pots. Is there info on this somewhere?

[Albert]

Is it possible to disassemble one of Atari's games (such as Centipede) to see exactly how they are calibrating the Trak-Ball controller? I haven't looked, but I assume proper source code isn't readily available.

 

..Al

[+Allan]

Curt posted the Galaxian source code which has trackball code in it. That might be useful.

 

Here it is:

 

http://www.atariage.com/forums/topic/121103-pam-galaxian-source-code/page__hl__%205200%20%20galaxian%20%20source

 

Allan

Edited October 20, 2012 by Allan

[+Cafeman]

I have a 2nd, boxed trakball. I got it out and created a Frankenstein , using the good rollers from TB1 (which is out of alignment though). readings for TB2:

 

Horiz: 123, 91, 166

Vert: 122,87,122 (no down motion detected at all)

 

But Tempest only checks Horizontal, so TB2 works pretty well with Tempest! It does not creep right or left, and it has satisfying control over the speed - I can craw along, or I can roll the ball hard and it moves almost as fast as joystick control's max speed.

 

But without any down control, I can't use my Frankenstein trakball for anything except Tempest!

 

EDIT - maybe I never experienced a perfectly functioning 5200 Trak-Ball, but I actually prefer just using the stick. This is true on other games like Centipede too - it seems I have to roll the ball way too much and I get tired of doing it.

 

I just played a few rounds of Tempest 5200 with the stick again - this game ROCKS and you don't need a Trak-ball to enjoy it because the joystick control is superb. It's just so well done.

Edited October 20, 2012 by Cafeman

[Charlie_]

EDIT - maybe I never experienced a perfectly functioning 5200 Trak-Ball, but I actually prefer just using the stick. This is true on other games like Centipede too - it seems I have to roll the ball way too much and I get tired of doing it.

 

 

Glad you got it working enough to play.

 

Do you think maybe it is not sensitive enough? In other words maybe you have to spin it too fast to get the max speed?

I know the knob on the arcades spinner, you dont have to really try too hard, just a fast twitch and it hauls ass.

[Charlie_]

BTW, here is Pete's Diagnostic rom for any one who has an SD / USB cart and wants to report the vaules.

Just press the TB, or Joy button to go through the tests until you see a screen with analog values...

Petes Diag.zip

[Albert]

BTW, here is Pete's Diagnostic rom for any one who has an SD / USB cart and wants to report the vaules.

Just press the TB, or Joy button to go through the tests until you see a screen with analog values...

 

I'd be glad to make this cart for anyone:

 

 

..Al

[+Cafeman]

Do you think maybe it is not sensitive enough? In other words maybe you have to spin it too fast to get the max speed?

I know the knob on the arcades spinner, you dont have to really try too hard, just a fast twitch and it hauls ass.

 

I'd say that my TB could be a bit more sensitive, yes. I've never experienced a brand new one, the only 2 I've ever owned were used to begin with, hence probably starting to be less effective than mint-in-the-box. But don't misunderstand, my 5200 TB is still a lot better than the 2600 one. I wonder if Dan Kramer would have anything to add about this subject? He has posted at AA before, but I think it was years ago.

[tep392]

I believe the 5200 trackball has calibration line that the program can pull low for setting the centered position. The program reads the "pot" values while the line is low and calls this centered. This just disables the encoderrs so the cal won't get messed up if the player spins the ball at the same time the program reads it..

[lucifershalo]

got mine,

thnks AL,

that s a bit of a shame that the text in the manual is incorrect

[+Cafeman]

Took some pics.

[Charlie_]

Took some pics.

 

Nice Onkyo receiver.

[+Cafeman]

I believe the 5200 trackball has calibration line that the program can pull low for setting the centered position. The program reads the "pot" values while the line is low and calls this centered. This just disables the encoderrs so the cal won't get messed up if the player spins the ball at the same time the program reads it..

 

So, are you saying there is no manual way to change a trakball's "centered/no movement" setting? For example, to change it from 105 to 120?

 

Instead, is it true the game programming has to have analog-detection logic to:

(a) determine if user is using a TB (how, as opposed to a centered stick being plugged in?);

(b) Take whatever the number value is for centered

© add and subtract "n" to get the left and right upper bounds

 

?

[Gabriel]

So, are you saying there is no manual way to change a trakball's "centered/no movement" setting?

 

That seems to be the case. Adjusting the pokey dial doesn't do squat to the reading for the trackball.

[tep392]

So, are you saying there is no manual way to change a trakball's "centered/no movement" setting? For example, to change it from 105 to 120?

 

Instead, is it true the game programming has to have analog-detection logic to:

(a) determine if user is using a TB (how, as opposed to a centered stick being plugged in?);

(b) Take whatever the number value is for centered

© add and subtract "n" to get the left and right upper bounds

 

?

I don't think there is any adjustment pot in the trackball. That doesn't mean you could change resistors or something similar to the unit to change the center. It's been a while since I looked at the schematic, but I remember it worked differently than the normal joystick controllers. The Pokey reads the joysticks be timing how long it takes a capacitor to discharge through the ristance of the pot. I think the trackball used a circuit that simulated the voltage being discharged and the rate that the voltage dropped varied with the speed of the ball. Might be possible to replace the resistors that control this with some small variable pots. But I might be totally mis-remembering how the circuit works. It has been a year or so since I looked at it.