2600 Analog Sticks?

[gliptitude]

I love the feel of analog joysticks and thumbsticks, even when they are not functionally analog.

 

VCS games are programmed for digital joysticks, but my go-to controller appears to contain analog components:

 

 

 

 

 

The TG Enjoystick was designed and marketed for an assortment of machines that program for digital joysticks(?):

 

 

 

 

(Image retreived: http://www.vintagecomputing.com/index.php/archives/508/retro-scan-of-the-week-the-enjoystick)

 

 

 

... How unusual is this? Are there others? Anybody else share this preference?

 

Vectrex has analog sticks standard, but hardly any of the original games actually use the analog .. and the few that do are practically unplayable! .. Yet the stick is beloved by Vectrex gamers and there is no controversy about using an analog stick primarily (almost exclusively) for digital directional controls.

 

Why don't we do this with the 2600?

 

I found this old article for making a convertor to use old Apple joysticks on VCS, but it seems much more complicated than making a permanent mod to the joystick:

 

http://www.atariarchives.org/ccc/chapter9.php

 

The Enjoystick looks very lean and simple in design, with no board inside. I imagine that some older computer analog joysticks are also this way, and that at worst in those instances potentiometers might be incorrect values, but that these could be swapped out within the mechanical assembly.

 

Is this possible? Or actually pretty difficult? .. I really love the controller I'm using but it is a pretty rare one and I'd like to have options and variety along these lines.

[+Stephen Moss]

Old PC game port style analogue Joysticks & I believe the 2600 use a systems where a capacitor is discharged and then allowed to charge through the resistance of the controller while a timer runs. When the voltage on the capacitor reached a pre-set level the value of the timer is indicative of the position of the controller as the charge time is determined by the resistance of the controller (variable) and the capacitor (fixed).

 

Whereas later systems such as early production models of the Jaguar had internal Analogue to Digital Controllers (ADC's) for reading the controller output voltage directly before switching to a similar systems as used by the PlayStation where the analogue to digital conversion is performed inside the controller which then outputs a corresponding 8 or 16 bit digital value.

 

The problem with trying to modify a controller such as the one shown above to make it work with digital input like those of the 2600 is twofold...

first there are not enough output connections, the VCS requires 5 (4 direction + fire) whereas the analogue controller requires 3 (Vertical, Horizontal and fire).

second is that controllers designed to charge a capacitor have their potentiometers wired as variable resistors (two wires only) whereas those going to an ADC usually have to be wired as potentiometer (3 wires). Therefore unless you add switches to switch between the two connection types you would no longer be able to use the Joystick with both types of system.

 

Having modified a Game Port style analogue stick for use with my Jaguar I am speaking from a point of some experience. In my case I used PIC microcontroller, because I wanted to integrate the Jaguar controller as well for access to the additional buttons my circuit and board was more complicated then you would need for a simple 4 directions + fire so a single 2 port 16 pin device with an internal clock source, at least two Analogue inputs and a couple of connectors (one to the VCS and one to the Joystick) should be all you need. Then you just program the microcontroller to read the analogue inputs and set the appropriate output lines high and low (don't for get to leave a dead band of analogue values in the middle of the range for neither direction).

 

Your other option is to use a comparator circuit as show in the link you provided, the advantage of the microcontroller is that it takes up approximately the same space as the comparator IC alone resulting in a smaller overall circuit size, if you use a reprogrammable one you can easily change the dead band just by changing to numbers in your code and the circuit is cheaper as you only need the one component, the disadvantage is you need to learn how to program it and the programmer hardware (i.e. PICKit 3 @ £30) to get you code into it. While the comparator circuit if correctly assembled requires no knowelege other than how to solder.

 

Either way unless there is something I am missing you are probably looking at an external interface board as opposed to an internal mod to the Joystick especially if you wanted to be able to use it on other systems in it original configuration. While the Microcontroller may fit inside the Joystick to allow it to be switched between VCS and original configuration would (assuming it was originally terminated with a 9 pin D connector like the VCS) require two double pole double throw switches to switch the potentiometer wiring configurations and analogue/digital out and I doubt you would get them in, let alone in somewhere they would not be intrusive.

[gliptitude]

Thanks for the reply Stephen. .. Based on your assessment it sounds like the easiest thing to do is just to follow the directions in the Apple to Atari project.

 

But to clarify..

 

The problem with trying to modify a controller such as the one shown above to make it work with digital input like those of the 2600 is twofold...

first there are not enough output connections, the VCS requires 5 (4 direction + fire) whereas the analogue controller requires 3 (Vertical, Horizontal and fire).

THE CONTROLLER IN THE PHOTOS IS ALREADY A 2600 CONTROLLER. I'm not trying to modify it and it has not been modified. It was originally intended for 2600.

 

I don't have the controller open anymore, (could open again later) but I don't think there are any capacitors in it and I think that all 3 tabs of each pot are wired.

 

.. I believe that The controller for the Vectrex console has 4 wires total connected to the two pots of the stick. There is one +5V that goes to both pots, one -5V also to both pots, and then each pot has a unique wire to its wiper. No ground.

 

.. May edit this with time.

[Cobra Commander]

I love the feel of analog joysticks and thumbsticks, even when they are not functionally analog.

 

VCS games are programmed for digital joysticks, but my go-to controller appears to contain analog components:

 

 

 

Those are likely not potentiometers, but axial type switches. Put a meter on them to find out. Its just mechanically different.

[AW127]

Funny. Two weeks ago, i tried my "PSX to 9PIN" Adapter on the Atari-2600 and played some games with it. With this adapter, you can also use the analog-sticks of the PSX-controller and it works better than i thought to play the old games.

[Hyperboy]

Funny. Two weeks ago, i tried my "PSX to 9PIN" Adapter on the Atari-2600 and played some games with it. With this adapter, you can also use the analog-sticks of the PSX-controller and it works better than i thought to play the old games.

Where did you get your adapter?

[gliptitude]

Those are likely not potentiometers, but axial type switches. Put a meter on them to find out. Its just mechanically different.

 

I haven't got a meter and have never used one. .. If i did, would i be measuring voltage (with controller plugged into powered up console), and be reading a variable voltage IF it's potentiometer, but static if axial switches?

 

When i search "axial switch" i am getting results that are potentiometers. Can you point me to one for reference, or is there another name to identify this?

 

Here is a more explicit photo of the wiring:

 

 

 

 

And here is a simplified drawing:

 

 

 

 

I would expect more symmetry in the wiring of digital components, but I don't have a good grasp of this stuff. I presume the white wire is ground, since it goes to all three components. But the two (pots?) are wired differently and the one only has one colored wire to it.

[BigO]

The two "pots" must be switches. When rotated in one direction, the center pin will be connected with one of the outside pins. When rotated the other direction, the center pin will connect with the other outside pin.

That would make the center ground in an Atari 2600 joystick.

The outer two wires on one switch would be Left & Right inputs. The outer two wires on the other would be Up & Down inputs.

 

Using switches with that potentiometer style form factor is kinda slick from the manufacturing perspective. It would let the same joystick mechanism work either as an digital joystick or as an analog joystick if fit with potentiometers.

 

http://atariage.com/2600/archives/schematics/Schematic_2600_Accessories_High.html

[gliptitude]

The two "pots" must be switches. When rotated in one direction, the center pin will be connected with one of the outside pins. When rotated the other direction, the center pin will connect with the other outside pin.

That would make the center ground in an Atari 2600 joystick.

The outer two wires on one switch would be Left & Right inputs. The outer two wires on the other would be Up & Down inputs.

Yeah you make sense but the wire colors don't initially seem to match.

 

.. What would make sense and corroborate your assesment is if the BLACK wire is ground coming out of the cable lead, and the white one coming out of the lead is one of the direction signals. After the first black wire ground connection they used white wire to connect the other two grounds. Pretty simple I guess, just confusing that they changed colors midway and that the color they changed to was identical to one already in use.

Edited August 13, 2015 by gliptitude

[gliptitude]

Using switches with that potentiometer style form factor is kinda slick from the manufacturing perspective. It would let the same joystick mechanism work either as an digital joystick or as an analog joystick if fit with potentiometers.

So is it probable that similar switches could be attained to swap for the pots in old PC joysticks, (along with a 9 pin cable) to convert for Atari? Or is this more likely a very rare outdated component?

[BigO]

Yeah you make sense but the wire colors don't initially seem to match.

 

.. What would make sense and corroborate your assesment is if the BLACK wire is ground coming out of the cable lead, and the white one coming out of the lead is one of the direction signals. After the first black wire ground connection they used white wire to connect the other two grounds. Pretty simple I guess, just confusing that they changed colors midway and that the color they changed to was identical to one already in use.

I don't really have a way to know what color insulation they used on the wires in the 3rd party controller. Since you said "I haven't got a meter and have never used one", I didn't see any value in going into that detail in my assumptions about how this controller almost certainly must be working in the absence of any other visible, active electronics.

 

If you do want to get a meter (I highly recommend it), you'd be best to take resistance or continuity measurements with the joystick unplugged from the console. A meter with a beeping continuity mode will make short work of answering questions about which color wire connects to which pin on the controller port. Where I live, there's a well known Chinese-made tool store that routinely sells cheapo meters for around $5.

 

It would technically be possible to make a potentiometer based analog joystick behave in the same way, using some voltage divider and comparator trickery, or a microcontroller. But I don't think that's anything like what's going on here.

 

It's kind of a cool controller, I wouldn't mind having one myself.

Edited August 13, 2015 by BigO

[BigO]

So is it probable that similar switches could be attained to swap for the pots in old PC joysticks, (along with a 9 pin cable) to convert for Atari? Or is this more likely a very rare outdated component?

I tend to agree with your "rare, outdated component" assessment. But, I could be wrong.

It would be an "on-off-on" type of switch. I don't see too many of those and I have never seen one in a form factor that matches a potentiometer. But, now that I know they exist(ed), I'll keep my eyes open next time I hit my favorite surplus places.

Edited August 13, 2015 by BigO

[AW127]

Where did you get your adapter?

From Kipper2K-Shop. It`s this one here: http://kipper2k.com/psx.html

The user can program it`s own buttonmapping, which is really a cool function. You can even change left/right and up/down and then turn around controller and other funny stuff with it.

[Hyperboy]

From Kipper2K-Shop. It`s this one here: http://kipper2k.com/psx.html

The user can program it`s own buttonmapping, which is really a cool function. You can even change left/right and up/down and then turn around controller and other funny stuff with it.

Thank you, preparing to email order now.

[ave1]

Thank you, preparing to email order now.

Another way to do it is to buy a Tototek PS2 to Genesis adapter from their website and add a B.E.'s Autofire cable for Genesis controllers to it (obtained at Best Electronics website).

 

If you own a PS2 Phoenix Revolution controller you can put the left analog stick on the right side of the controller for some great right-handed control of 2600 games like Millipede and Missile Command. Feels great!

Edited August 14, 2015 by ave1

[ave1]

I love the feel of analog joysticks and thumbsticks, even when they are not functionally analog.

VCS games are programmed for digital joysticks, but my go-to controller appears to contain analog components:

The TG Enjoystick was designed and marketed for an assortment of machines that program for digital joysticks(?):

(Image retreived: http://www.vintagecomputing.com/index.php/archives/508/retro-scan-of-the-week-the-enjoystick)

... How unusual is this? Are there others? Anybody else share this preference?

Vectrex has analog sticks standard, but hardly any of the original games actually use the analog .. and the few that do are practically unplayable! .. Yet the stick is beloved by Vectrex gamers and there is no controversy about using an analog stick primarily (almost exclusively) for digital directional controls.

Why don't we do this with the 2600?

I found this old article for making a convertor to use old Apple joysticks on VCS, but it seems much more complicated than making a permanent mod to the joystick:http://www.atariarchives.org/ccc/chapter9.php

The Enjoystick looks very lean and simple in design, with no board inside. I imagine that some older computer analog joysticks are also this way, and that at worst in those instances potentiometers might be incorrect values, but that these could be swapped out within the mechanical assembly.

Is this possible? Or actually pretty difficult? .. I really love the controller I'm using but it is a pretty rare one and I'd like to have options and variety along these lines.

I found this for you. Yes, it's possible http://m.ebay.com/itm/DB-15-PIN-PC-JOYSTICK-ADAPTER-FOR-AMIGA-ATARI-COMMODORE-D-SUB-9-PIN-GAMEPORT-/111729003284?nav=SEARCH

[AW127]

Another way to do it is to buy a Tototek PS2 to Genesis adapter...

I am not sure about using Genesis (Mega-Drive) controllers on other 9Pin-systems, because of this 5V which is on one Pin, that other 9Pin systems dont have. C64 can be harmed (CIA chip) and so on. Not sure how sensitive other systems react to Genesis controllers? And maybe there is the same problematic when a Genesis controller-adapter is used? Therefore i feel more safe with an Amiga controller-adapter, because this is exactly the same 9Pin-schematic like on the Atari-2600.

 

Maybe anybody knows more, how sensitive the Atari reacts on the different Genesis 9Pin wiring?

 

By the way, i have here lots and lots of controller-adapters. Also i have such a "PSX to Genesis" TOTOTEK Adapter that you mentioned here and also a "PSX to SNES" adapter from TOTOTEK. But i only use them on Mega-Drive and Super-NES, and the Genesis-adapter not on any other 9Pin-product. These are also good adapters, but you dont have the button cloning feature, which Kippers "PSX to Amiga" adapter has and which is really great and unique. And Autofire is also already included in Kippers adapter.

Edited August 14, 2015 by AW127

[ave1]

AW127, the B.E.'s Genesis Autofire adapter gets Genesis controllers which have an autofire feature working the way they should with that autofire feature on Atari systems (8 bit computers and 2600), by getting that 5V which is on the "wrong" pin of the controller plug end put on the right pin. One bonus of this is that it also gets the Playstation controller working through the Tototek PS2-to-Genesis adapter on those Atari systems.

 

You can safely use the two adapters connected together because the voltage is set up in a proper way. Atari systems controller ports are not at risk for controller port short-outs with Genesis controllers like the C64's are. In my time here no one in this forum has ever come forward with a story of a Genesis controller-related controller port short-out on an Atari system.

 

If you look at this thread: http://atariage.com/forums/topic/238049-new-discovery-get-master-sys-ctlrs-to-work-w-edladdin-seagull78-adapter/

 

You'll find if you scroll down a bit that Trebor has a bit to say about this. Also, I respond to Trebor in that thread with more evidence which seems to indicate the 2600 is in no danger when it comes to the use of Genesis controllers.

Edited August 15, 2015 by ave1

[AW127]

AW127, the B.E.'s Genesis Autofire adapter gets Genesis controllers which have an autofire feature working the way they should with that autofire feature on Atari systems (8 bit computers and 2600), by getting that 5V which is on the "wrong" pin of the controller plug end put on the right pin... One bonus of this is that it also gets the Playstation controller working through the Tototek PS2-to-Genesis adapter on those Atari systems.

Ah interesting, then its safe because of this adapter. I must search the internet and read about these "B.E.'s Genesis Autofire adapter". Never heard about this adapter before. Nevertheless you have not the "cloning button" feature which Kippers adapter has.

 

You'll find if you scroll down a bit that Trebor has a bit to say about this. Also, I respond to Trebor in that thread with more evidence which seems to indicate the 2600 is in no danger when it comes to the use of Genesis controllers.

Good to know. Then the Atari-2600 is not so sensitive to Genesis controllers like the C64. I have never used any of my Genesis pads or sticks on another 9Pin-system until now, because of fear to break something. So i dont trust to 100% that its totally safe.

 

By the way, for the C64 (and other 9Pin systems) there also exist the 64JPX-adapter in different versions, which allows connecting SNES, Genesis, PC-analog and NES sticks to 9Pin-systems. I also have one of these here in the purple version (SNES/GENESIS) and the Genesis-variant of this adapter has a diode-protection included. In the manual of these 64JPX-adapter is written this sentence "Provides diode protection to Commodore and Atari systems". Sounds like also Atari systems needed some kind of protection from Genesis controllers? But i dont know, what can really happen and what not, because like i said, i never tried Atari-sticks on Genesis and never tried Genesis-pads on other 9Pin systems.

 

Will read now the thread that you linked about this thing, maybe i find out something new.

[gliptitude]

I found this for you. Yes, it's possible http://m.ebay.com/itm/DB-15-PIN-PC-JOYSTICK-ADAPTER-FOR-AMIGA-ATARI-COMMODORE-D-SUB-9-PIN-GAMEPORT-/111729003284?nav=SEARCH

Thanks for sharing this. It is interesting and maybe a very simple solution. But it makes me nervous that there is no explanation of how it works. It looks too small to accomodate the electronics that others have prescribed so i would think that there would have to be something pretty special going on inside there for this to be legit. Plus there is no way this is compatible with EVERY 9 pin machine like the seller claims because not all systems have the same pin outs .. Unless it is somehow programmable, which again you would think there would be some expanation if it was.

 

Still it might be OK with Atari though, which i guess is all i was originally asking about.

[ave1]

Ah interesting, then its safe because of this adapter. I must search the internet and read about these "B.E.'s Genesis Autofire adapter". Never heard about this adapter before. Nevertheless you have not the "cloning button" feature which Kippers adapter has.

 

Good to know. Then the Atari-2600 is not so sensitive to Genesis controllers like the C64. I have never used any of my Genesis pads or sticks on another 9Pin-system until now, because of fear to break something. So i dont trust to 100% that its totally safe.

By the way, for the C64 (and other 9Pin systems) there also exist the 64JPX-adapter in different versions, which allows connecting SNES, Genesis, PC-analog and NES sticks to 9Pin-systems. I also have one of these here in the purple version (SNES/GENESIS) and the Genesis-variant of this adapter has a diode-protection included. In the manual of these 64JPX-adapter is written this sentence "Provides diode protection to Commodore and Atari systems". Sounds like also Atari systems needed some kind of protection from Genesis controllers? But i dont know, what can really happen and what not, because like i said, i never tried Atari-sticks on Genesis and never tried Genesis-pads on other 9Pin systems.

Will read now the thread that you linked about this thing, maybe i find out something new.

I'd like to own a Kipper Atari adapter, but I'm probably just going to stick with the ones I use because I'm very satisfied with their performance and kinda want to save my money.

 

That is interesting about the statement in the 64JPX-adapter manual... Not sure why they included Atari systems in that statement having to do with protection.

[ave1]

Gliptitude, I am sure that if you ordered one and it didn't work properly, you could have the seller or Ebay refund you your money.

 

It is interesting that the ebay seller states that all 9 pin port controllers will work. He probably meant that all early and mid-80s 9 pin port controllers will work. 3DO, for instance, would certainly not work even though it's a 9 pin.... but that's a 90's product which he probably never thought of.

[+Stephen Moss]

@ gliptitude

sorry I should have looked more closely at the text on the uploaded advert for your joystick, I thought you had an analogue controller designed for another system that you wanted to use with the 2600.

 

I agree with others here in that I do not think it is analogue but digital switches as it would not work with the VCS if it were, nor would it be wired as it is with what would be the wiper of a potentiometer connector to ground as that would make no sense.

 

In regard to the adaptor on E-bay it may be possible to fit the circuitry in there if surface mount components are used, in which case the IC required for the quad comparator could easily be as small a 1 x 0.5 cm and resistors/capacitors 2 x 1 mm. Personally I would not want to flex that ribbon cable to much to prevent fatigue, the lack of operational description may just be to prevent people from Googling how to do it themselves.

[gliptitude]

I tend to agree with your "rare, outdated component" assessment. But, I could be wrong.

It would be an "on-off-on" type of switch. I don't see too many of those and I have never seen one in a form factor that matches a potentiometer. But, now that I know they exist(ed), I'll keep my eyes open next time I hit my favorite surplus places.

 

I think that this is a picture of the conductive/resistive element of a typical potentiometer:

 

 

 

Retrieved from: http://www.geofex.com/article_folders/potsecrets/potscret.htm

 

The same page describes some possibilities for manipulating this portion of the component and reassembling the potentiometer for different results.

 

Isn't it possible that this element could be modified and reassembled to produce an on-off-on switch? Maybe just removing the resistive coating and then cutting the copper at the peak of the arch? (And rewiring for Atari digital pinouts)

 

Alternatively couldn't that one element be manufactured to that end with shop equipment suited to PCB printing/cutting?

[BigO]

I think that this is a picture of the conductive/resistive element of a typical potentiometer:

 

 

 

Retrieved from: http://www.geofex.com/article_folders/potsecrets/potscret.htm

 

The same page describes some possibilities for manipulating this portion of the component and reassembling the potentiometer for different results.

 

Isn't it possible that this element could be modified and reassembled to produce an on-off-on switch? Maybe just removing the resistive coating and then cutting the copper at the peak of the arch? (And rewiring for Atari digital pinouts)

 

Alternatively couldn't that one element be manufactured to that end with shop equipment suited to PCB printing/cutting?

Good point.

 

Depending on how the wiper is constructed, it could be possible to adapt an existing potentiometer. I don't think you'd want to cut any copper..

Electrically speaking, if you just removed all of the resistive(conductive) material, the center contact would be connected to nothing until the potentiometer was rotated to it's extremes. That could be used to trigger the joystick inputs on a 2600.

 

I don't think a typical joystick mechanism would hit the extreme ends of the pot travel so you'd want to extend the live areas further into the center of the rotational range.

 

I think you could start with a standard pot, the lower the resistance the better. Remove the conductive/resistive material in the center of rotation to create a dead spot. This would decouple the two outer contacts from one another and prevent the center conductor from having any electrical contact with the outer legs of the pot while in the center position. Wire it up with ground on the center conductor and UP/DOWN or LEFT/RIGHT on the outer conductors.

 

Even though you'd technically have some resistance I'd expect the 2600's digital logic to respond when the pot is rotated enough to connect the remaining resistive material to the center conductor. Since there's very little current flow, there will be very little voltage drop across the resistive material. I suspect that this would work with the typical 10K pots found in analog joysticks.

 

If it works, you can then adjust the size of the dead spot to your liking.

 

Would be worth a shot. As long as you only use the wires available to the original joystick, I don't see how you could hurt your console by trying this even if you hook it up wrong.

 

Maybe I'll try it with one of the PC joysticks I have laying around when I get some spare time. Of course, such a modified joystick could never work as an analog one again.