7800 Centipede Trak-ball Conversion

[Danno]

Does anyone out there have a disassembly of 7800 Centipede?

 

I'm wondering if it's controller scheme can be converted to use the CX-80 Trak-ball in true trak-ball mode.

Edited May 1, 2005 by Danno

[EricBall]

7800 disassemblies are few and far between, and I don't believe one has been done for Centipede.

 

How does a CX-80 TB work? Is it like a driving controller (or mouse, or Tempest spinner) with has two signals, clock and direction, per axis? Or is it more like a paddle with a variable resistance?

 

In either case I think the TB has to be sampled multiple times per screen. On a 7800 I'd recommend invoking the DLI once per zone to sample the controller. I think this would be okay for a spinner, but too low-res for a paddle.

[Danno]

7800 disassemblies are few and far between, and I don't believe one has been done for Centipede.

 

How does a CX-80 TB work?  Is it like a driving controller (or mouse, or Tempest spinner) with has two signals, clock and direction, per axis?  Or is it more like a paddle with a variable resistance?

 

In either case I think the TB has to be sampled multiple times per screen.  On a 7800 I'd recommend invoking the DLI once per zone to sample the controller.  I think this would be okay for a spinner, but too low-res for a paddle.

848190[/snapback]

 

I'm not sure, but I think it's like the driving controller/spinner type, yet operating on two axes simultaneously.

 

It's like a dumbed dowm PC. mouse. It's got pinwheels and optics, just like a mouse.

[Rob Mitchell]

I'm not sure, but I think it's like the driving controller/spinner type, yet operating on two axes simultaneously.

 

It's like a dumbed dowm PC. mouse. It's got pinwheels and optics, just like a mouse.

848210[/snapback]

 

That's right. It is a low resolution quadrature encoder in two axis. But the 2 trakballs are not exactly the same. Thus Thomas made 2 different Missile Command hacks to use various trakball schemes.

 

Rob Mitchell, Atlanta, GA

Edited May 3, 2005 by Rob Mitchell

[EricBall]

Hmm, okay. Is there anyone out there with both a CC2 and a trackball? I've found some programming data for the CX-22, but I think the CX-80 is slightly different. If someone can provide references, I can put together a quick test app.

[vdub_bobby]

Hmm, okay. Is there anyone out there with both a CC2 and a trackball?  I've found some programming data for the CX-22, but I think the CX-80 is slightly different.  If someone can provide references, I can put together a quick test app.

848604[/snapback]

 

Here are some comments from Thomas J's source for the Missile Command track ball hack he made; these might help.

;Trackball CX-22

;1 L/R sense (0 = left)

;2 L/R reference

;3 U/D sense (0 = up)

;4 U/D reference

;6 button

;7 +5V

;8 GND

;

;ST Mouse

;1 L/R sense (0 = right

;2 L/R reference

;3 U/D sense (0 = down)

;4 U/D reference

;6 L button

;7 +5V

;8 GND

;9 R button

;

;Amiga Mouse

;1 U/D reference

;2 L/R reference

;3 U/D sense

;4 L/R sense

;5 M button

;6 L button

;7 +5V

;8 GND

;9 R button

and this:

CX_80      = 0    ; YYXXyyxx

CX_22      = 0    ; YYXXyyxx

MOUSE      = 1    ; XYXYxyxy

But your best bet is probably to ask Thomas himself

[+Mitch]

If I recall, there were two different versions of the CX80, one was the same as the ST mouse and the other was the same as the CX22.

 

Mitch

[Danno]

I have a CX-80 Trak-Ball, and my CC2 is in the hands of Fedex as we speak.

 

My only problem - I don't know squat about programming for Atari or 6502.

 

I was just hoping I could get a few people to put their heads to gether and give this idea a whirl.

[Danno]

Hmm, okay. Is there anyone out there with both a CC2 and a trackball?  I've found some programming data for the CX-22, but I think the CX-80 is slightly different.  If someone can provide references, I can put together a quick test app.

848604[/snapback]

 

Here are some comments from Thomas J's source for the Missile Command track ball hack he made; these might help.

;Trackball CX-22

;1 L/R sense (0 = left)

;2 L/R reference

;3 U/D sense (0 = up)

;4 U/D reference

;6 button

;7 +5V

;8 GND

;

;ST Mouse

;1 L/R sense (0 = right

;2 L/R reference

;3 U/D sense (0 = down)

;4 U/D reference

;6 L button

;7 +5V

;8 GND

;9 R button

;

;Amiga Mouse

;1 U/D reference

;2 L/R reference

;3 U/D sense

;4 L/R sense

;5 M button

;6 L button

;7 +5V

;8 GND

;9 R button

and this:

CX_80      = 0    ; YYXXyyxx

CX_22      = 0    ; YYXXyyxx

MOUSE      = 1    ; XYXYxyxy

But your best bet is probably to ask Thomas himself

848630[/snapback]

 

Those are the pinouts.

 

I actually rewired teh optics of my CX-80 to a mitsumi serial mouse, but now taht I have a working 7800 and a CC2 on the way - I'm going to reverse the sex change operation I performed on it.

[EricBall]

See my AtariAge blog for a trackball proof of concept program. I would be interesting in knowing how well it works.

[+Allan]

See my AtariAge blog for a trackball proof of concept program.  I would be interesting in knowing how well it works.

853009[/snapback]

 

It seems to work. Rolling in one direction should make one number keep going up or down, right?

 

Allan

[EricBall]

Correct. The display is Player 1 X, P1Y, P2X, P2Y. The numbers should increase/decrease as you roll the ball, the faster you roll, the faster the numbers should change.