[NES classic (mini) controller mod.]

Two players all set up.  Again, I'll try solving the A & B button wired to the Fire button problem later.  Will also try to get the Power button to get me out of the game and back to the menu using Select/Down.

[NES classic (mini) controller mod.]

OK, I partially did the Flashback/NES Classic joystick adapter mod today.  Soldered the Flashback's joystick port #1 to the NES controller as well as the Select and Start buttons.  Everything works fine.

BUT

1) Connecting the joystick Fire button to both the A and B NES controller buttons didn't work as hoped.  When using the joystick in the menu and pressing the Fire button to select a game it chooses to use the B button (going to the Save menu) over the A button (which would have selected the game).  I have to use the Flashback to choose the game I want to play.

2) For some reason I couldn't just ground to the Flashback buttons to the NES controller once and wire the Select and Start buttons to the NES controller.  It always thought pressing Start or Select on the Flashback was pressing both at the same time, which takes you to the systems settings (where you can potentially screw things up).  I actually had to cut the thin circuit board running the length of the Flashback buttons in two and ground each side separately in order for it not to read pressing Select or Start as pressing them both.

3) I did not yet try to wire the Flashback Power button to both the Select and Down buttons on the NES controller in order to use the Power button to exit games and return to the menu.  Since the Power button stays depressed until you push it again, I'm not sure if it will work OK.  Plus, I might have a similar problem as I did with Select/Start. 

Any suggestions on #1?  Did you have any issues with #3?

I'll try to solve #1 and get #3 done this week as well as hooking up port #2 to a second NES controller to allow for 2 joysticks for two player games.

[NES classic (mini) controller mod.]

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 male joystick port (#1) 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.

 

[NES classic (mini) controller mod.]

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 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.

[NES classic (mini) controller mod.]

Mapping the pins/wiring for an Atari joystick is incredibly easy, but both the type of controller you used 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.

Do 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) do 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 (for the extra Home button function) with an Atari Flashback and wiring the joystick port pins 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.  That means you'd have to connect port 2 to a controller like you did and have two NES Classic controller wires coming out of the Flashback.  But it would be worth it.

But actually doing that seems difficult.

[NES classic (mini) controller mod.]

So which wires from the joystick go to which in the NES Classic controller?