Latest 5200 Project.

[Aswald]

http://www.atariage.com/forums/index.php?showtopic=119395


If you check out the diagrams, you'll notice that I rebuilt an ordinary joystick, installing 2 "normally closed" switches in it for Down and Right.

The reason for this was that originally there was no way to use a normally OPEN switch (regular) to increase overall resistance.

For the past week or so, using the usual scraps and such I'm stuck with, I tried a number of things to get around this. Finally, last Sunday, I touched end of wire to the negative, and...

The cursor on Missile Command moved DOWN a bit.

That was it.

I've finally come up with a design in which you can have a working digital 5200 joystick with FOUR normally open switches.

So- instead of a joystick, I'm working on the obvious:

A proper 9-Pin Digital Joystick-to-5200 adapter.

It will also accept the 2600 paddles, although a switch is necessary for the left/right/fire circuits (2600 paddle fire buttons act as left and right joystick moves; the 5200 directly uses the fire buttons).

So far, I have built the basic 4-direction circuits. It works so far. Today, the fire button scheme. I will use the ColecoVision and 7800 joysticks as a basis. The 0-9, *, #, START, PAUSE, and RESET buttons will be on the adapter itself.

What makes this nifty is the fact that you merely have to plug in a "normal" joystick. It will not be soldered in, or altered in any way.

[Aswald]

My orginal design for this item required 6 relays, and a AA battery. This one requieres no battery- just plug the joystick in, and possibly adjust the potentiometers. Once set, though, it should be fine.

[Orion Pimpdaddy]

I can't quite comprehend everything you are saying, but I am glad there are people out there willing to share their inventive ideas with others. Thanks.

[Pezcore343]

Just read over your notes on how the 5200 joystick works instead of listening to my Anatomy professor. Good stuff. Thanks for sharing.

[boatofcar]

Let me beat Pantechnicon to the punch here and say:

Pics or it didn't happen.

[Aswald]

Let me beat Pantechnicon to the punch here and say:

Pics or it didn't happen.


I sent the pics three months ago- they have yet to be published here, as I was assured they'd be two months ago (they were received). So no, I won't bother with any more pics.


In any case, the project I'm now working on is not 100% complete. 7800 and most joysticks work, but not CV controllers. Probably those diodes they have; most others do not- they're pretty straightforward.

A bigger problem is "drift." This can cause something to move when it shouldn't; unlike my 5200 joystck, neutral is not stable. I have narrowed the problem down to one likely place, and believe that the 10 meg resistor I'm using is much too high (the SLIGHTEST variation in current can have a significant effect, with that high a resistance). Until I can find or buy better ones (maybe those 470,000 ones again), though, it'll be hard to find out. Be assured that if I can perfect this thing, I will try to publish diagrams on how to build it, most likely at Atari Age again.


There is absolutely no doubt that the standard 5200 controllers were a handicap. Digital ones make 5200 games so much better, it's difficult to describe.

[Aswald]

Well, the resistor was the source of that "drift."

All I have to do now is pick up a few 500,000 OHM resistors, and I can build the thing.

CV controllers still won't work, but for now I'm not going to worry about it. 7800 controllers work best, I've noticed.

[Pantechnicon]

Let me beat Pantechnicon to the punch here and say:

Pics or it didn't happen.

You'll shoulder the burden for that line alone, because in fairness I have to confess that Aswald has, in fact, sent me actual pictures of his last controller project. To paraphrase Seinfeld: It's real, and it's fantastic. I just haven't put the pics online as I promised I would, and he's been exceptionally patient about this. I'll try and get them up this week.

[boatofcar]

I apologize, then. I look forward to seeing the pictures!

[TheDomesticInstitution]

I'm curious, is this a device of some sort? Do you plug it into the controller port on the console and then plug in your controller of (your given) choice? Or is it a modified controller? This sounds pretty cool, and I can't wait to see the pics.

[Ze_ro]

I'm very curious to see how you've managed to do this with only passive devices... pics please.

--Zero

[Aswald]

I'm curious, is this a device of some sort? Do you plug it into the controller port on the console and then plug in your controller of (your given) choice? Or is it a modified controller? This sounds pretty cool, and I can't wait to see the pics.

It is an adapter you plug into the 5200; you then plug a 9-pin controller into the adapter. It has the standard 15 keypad buttons on it (0-9, *, #, START, PAUSE, and RESET).

This particular design will not allow you to use a CV controller. The problem is that for UP and LEFT, you have to bypass the potentiometer (variable resistor) that keeps the current for NEUTRAL; since the four directions in a CV controller must be on the negative side, these two are not and so will not work. Since all four directions connect to a common in the joystick, and the UP and LEFT must also work with this, the polarities do not work out.

If you try to switch the polarities around, then the DOWN and RIGHT will not work.

For some reason Atari 7800 controllers work the best with it (very well). Gimstick and 2600 controllers, not quite as well so far. I do not know why this is, since all use simple normally open switches. I can only assume that the 7800 controller has better quality switches that maintain better contact.

It is also designed to use a 2600 paddle controller. Since there is only one fire button, you cannot properly play Pole Position.

Incidently, the fire buttons on the 2600 paddle controllers are actually the same as joystick left and right. It was the only way Atari could have fire buttons on TWO paddle controllers plugged into ONE 2600 plug. This was a pain to figure out for this adapter.

[Aswald]

I took apart the Gimstick controller, and pushed down the "bubble" switches- it works. The problem is that excellent contact must be made, since so little current can go through.


I've modified the design- I'll try it today or tomorrow; if it works, then CV controllers will work.

Since CV controllers have good switching, this would be a great thing.

[TheDomesticInstitution]

This all sounds really cool, especially to get the CV controllers working. Maybe you could sell the thing? Looking forward to the pictures, Pan.