With NES/SNES Classic consoles being modded to allow for games from other systems to be played, such as Atari 2600, I was wondering if anyone has modded an Atari joystick to work on a Classic unit.  I saw one guy make videos showing that he did it, once through a NES-style aftermarket controller for NES Classic, and once through an Atari Flashback 4, but provided absolutely no details regarding wiring.  I messaged him about it and he said he'd look into wiring diagrams, but never got back to me.



Mapping the pins/wiring for a joystick is incredibly easy, but Wii Classic controllers are way more complicated.  There is no wire out of the controller for each function like old controllers.

Has anyone done this successfully?

As I said in the OP, mapping the pins/wiring for an Atari joystick is incredibly easy, but both the type of controller used in the videos and the Wii Classic controllers (which are great because they can utilize the Home button to get you out of a game and back to the menu) are way more complicated.  There is no wire out of the controller for each function like old controllers.  Apparently wires out of those controllers share more than one function.

Would you have to find the right traces for each (up, down, left, right, fire button, and power/ground) to solder the joystick wires to?  And when connecting through a Flashback (which seems much more useful) would you have to find the right traces for each NES Classic-style function (Select, Start, and Home buttons)?

It seems the best setup would be using a Wii Classic controller clone (for the extra Home button function) with an Atari Flashback and wiring the Flashback joystick port pins to the Wii Classic controller for the basic control movements and then wiring the Flashback's Power, Select, and Start buttons to the controller's Home, Select, and Start buttons, respectively.  I'm not sure if the difficulty buttons could be utilized or not, but would be awesome if they could be.

And also, using the Player 2 joystick port with a second controller (wouldn't have to be a Wii Classic) to allow for two players using Atari joysticks for two-player games would be ideal.

But actually doing that seems difficult.

I have a cruddy after-market Wii Classic controller as well as an after-market regular NES controller for the NES Classic. I spent $15 combined on them. I also ordered a dirt cheap Flashback 2 for $8 with shipping included.

Now I just need ideas and help on how to make this pipe dream a reality.

So I did some experimenting with my cheap aftermarket Wii Classic controller and it worked pretty well when I tested it. Each of the 6 buttons on the NES controller (left, right, up , down, A, and B) have two parts. When the NES controller is assembled pressing each of the buttons creates a connection between the two parts and activates that button.

You can wire the 4 directions and the fire button on the Atari joystick to one side of each of the 6 two-part NES controller buttons. Then wire the 6 Atari joystick ground wires to the other side of each NES controller button.

When looking at the female end of the Atari connector the pins will be 54321 on the top and 9876 on the bottom. Here's what I did:

1) Split the ground wire (Atari joystick pin #8) into 6 wires, one for each direction and one each for the A & B buttons.
2) Wire those 6 ground wires to one side of the each of the 6 NES controller buttons we care about (left, right, up , down, A, and B). It appears that connecting them to either side of the two-part NES buttons works fine.
3) Wire the 4 Atari joystick directional wires to the 4 NES controller directional spots on the side opposite where you wired each ground wire.
Pin #1 - Up
Pin #2 - Down
Pin #3 - Left
Pin #4 - Right
4) Split the Atari joystick fire button into two and wire them to the A and B buttons of the NES controller like in step 3.
Pin #6 - Fire button

The four directions work perfectly and the fire button presses A and B simultaneously, which on a modded NES/SNES Classic is fine because only A or B are ever usable on any screen at any time when it comes to the Atari menu/games, not both.

I only messed things up when I went to make the wiring permanent instead of having the wires taped in place. I am not good at soldering and the circuit board is just too small for me. I jacked it all up. If I want this to really work I'll have to find help in that department.

Upon more consideration, I will adjust my earlier post with this:

To hook up a joystick to a NES-style controller for the NES Classic:
1) No need to split the ground wire (Atari joystick pin #8) into 6 wires like I originally stated. Grounding the joystick once on the controller circuit board should do.
2) The aftermarket controller I used (not the Wii Classic clone) has a specific ground side for each button (see pics). The ground trace runs around the entire perimeter of the board so that all the Dpad buttons on the left have the ground on the left, the A & B buttons on the right have the ground on the right, and the grounds for Select & Start are in the middle of them.
3) Wire the 4 Atari joystick directional wires to the 4 NES controller directional spots on the side opposite where each ground spot is.
Pin #1 - Up, Pin #2 - Down, Pin #3 - Left, Pin #4 - Right
4) Split the Atari joystick fire button into two and wire them to the A and B buttons of the NES controller like in step 3. Since on a modded NES Classic A is used primarily to select folders and games and B is primarily used only as the Fire button in the Atari games, this setup should work fine. Pin #6 of the joystick is the Fire button

To hook up a joystick to a NES-style controller for the NES Classic through an Atari Flashback (in theory, I have not done it yet):
1) Do all the same steps, 1-4, above only instead of using the wires from your joystick pins use the corresponding wires from the Flashback's male joystick port to hook up to the NES-style controller, all in the same way as with the joystick. So when you plug in your joystick to the Flashback port you are essentially still connecting your joystick to the NES-style controller, just through the Flashback.
2) Take the ground wire from one of the Flashback console buttons and wire it to the NES-style controller in any grounding spot on the circuit board.  The joystick port (both ports if you're using both of them) and one of the Flashback console buttons must be grounded.  Grounding just one or the other will not do, they are 2 (or 3 if both joystick ports are wired up) separate entities that each need to be grounded.
3) You can do the exact same for port #2 to allow for 2 joysticks to be used (Player 1 and Player 2). You will have the controller cords for each NES-style controller coming out of the Flashback, but I don't think anyone cares.
4) Wire the hot wire from the Flashback Select button to the NES-style controller Select button. Do likewise for the Start button. You DON'T need to do this step to the Player 2 controller.
5) I THINK this step will work, but someone correct me if I'm wrong. Since my modded NES allows you to leave a game and go back to the menu (like the Home button would do with a Wii Classic controller) when Select and Down are held simultaneously, you can wire the Flashback's Power button to BOTH the Select and Down buttons of the NES-style controller. Holding down the Flashback's Power button for two or so seconds will take you out of the game and back to the menu. Again, only do this to the Player 1 controller.
6) The Flashback's Difficulty buttons may be able to be used to set the difficulty. I'm not sure yet.

This all looks right to me and the first part has been tested on the controller pictured. I haven't attempted soldering yet because I suck at it, but there seems to be a lot more room on these controllers than the Wii Classic clone I originally tried, so I'm hoping I won't mess it up.

Let me know if you have suggestions/ideas that can help me or the next guy.

So how the nes controller works is that it used a shift register which was different than an atari controller. My thoughts is just to make an adapter in kicad with one of these shift registers and a DB9. If I have time at some point this weekend I might be able to make an adapter like this.
edit- nevermind, I didn't see you said nes Classic which uses a different setup...

Here's what it looks like.