AV Famicom and an aftermarket 4-player adapter issue

[yojc]

Hi all,

I have just acquired a custom 4-player adapter for the Famicom (not the semi-official Hori one from back in the day), which allows you to connect two NES/AV Famicom controllers via the Famicom expansion port. It's the same one that was once sold on Amazon, it looks exactly like this:



I'm still new to the retro consoles (just started collecting a few months ago), and something I quickly came to realise is that things often aren't as straightforward as they seem, and you come across many weird quirks all the time. This case is clearly no exception.

Basically, the issue is that I can't figure out how to get this thing to work properly. I own an AV Famicom and seven NES controllers: four original European (NES-004E), one original Japanese (HVC-102), and two aftermarket NTSC controllers. Each one of the gamepads works with the console itself without any issues.

However, when connecting these to the aforementioned 4-player adapter, things get really... odd:

- none of the European gamepads work at all with this adapter. No response whatsoever.
- HVC-102 works, but it controls the player 3 while connected to the either port of the adapter.
- aftermarket NTSC controller works, but it controls the player 3 while connected to the either port of the adapter.
- when connecting both the HVC-102 and the aftermarket controller, the HVC-102 is not responding at all. The aftermarket one controls the player 3 while connected to the either port of the adapter.
- when connecting both aftermarket controllers, both of them control the player 3.

//edit: to clarify, while testing the adapter I had either two NES-004E controllers or an european Four Score (with two NES-004E) connected to the two main controller ports on the AV Famicom.

...the hell? I have no idea what's going on there, seriously. At the moment I have no reason to assume the adapter is at fault, but rather for some reason AV Famicom is extremely picky when it comes to the controllers connected via the expansion port. But the question is - which controllers should I use to be able to control player 3 and 4? Two HVC-102? Two NES-004? Or maybe I can use each one of these?
Has anyone used this or a similar adapter and can shed some light on the subject?

I have tested several 4-player titles (Kunio-kun no Nekketsu Soccer League, Nekketsu Street Basket: Ganbare Dunk Heroes, U.S. Championship V'Ball) and I get the same results every time. Mind you I'm not using the real carts but rather the Everdrive N8, but that shouldn't affect this issue I think.

Any ideas?

[Great Hierophant]

Official European NES controllers are region locked, they only work with PAL consoles.  I believe that US NES and Famicom AV controllers can work in PAL NES Consoles, but the reverse is not true.  I do not know if the Four Score conditions the European controllers to work with NTSC consoles.

It seems like your adapter may be defective given that both controllers appear to control Player 3.  Player 3 and Player 4 use different pins to send their data.  If you can check the continuity of the pins with a multi-meter, you can find out for sure.  Use these pages as a reference :

http://wiki.nesdev.com/w/index.php/Controller_port_pinout
http://wiki.nesdev.com/w/index.php/Expansion_port

I think that adapter may not be a true four player adapter,  It may be that one or both of the ports has been designed to allow a light gun to work with the AV Famicom. 

You may want to try Super Mario Bros as a test, it is a game that will read Player 3 as Player 1 and Player 4 as Player 2.

[yojc]

Official European NES controllers are region locked, they only work with PAL consoles.  I believe that US NES and Famicom AV controllers can work in PAL NES Consoles, but the reverse is not true.

Erm... if i'm not mistaken, it's actually the opposite. EU NES works only with EU controllers (IIRC the Swedish NES is an exception), while the US NES and AV Famicom work with all controllers (EU/US/JP). European Four Score has the same region lock as the NES and works only with EU controllers. (well, almost... HVC-102 works on the EU Four Score, but the aftermarket NTSC controllers don't  )
As I said before, I own the EU Four Score and EU NES-004E controllers, and they all work flawlessly on the AV Famicom. That is - they work when I'm connecting them to the controllers ports, not to the expansion port via the adapter.

Anyway...

My suspicion is that the console itself does some checks to detect how many controllers are hooked up to the expansion port, and if it finds any, it then assigns them the 'available' player number. (I have next to zero knowledge of the NES/Famicom hardware, so that probably doesn't hold true.) That would explain why I can only get the player 3 to work on the either connector. It doesn't explain why on Earth connecting an aftermarket controller and HVC-102 results in the latter not responding (while the HVC-102 works when connected on its own), and connecting two aftermarket ones results in them both controlling the same player... this just baffles me.

I'll try to check the pinout with the multimeter, thanks for the tip. Another thing I might try is making a crude SNES to NES adapter, and check how does the Super Famicom controller fare with this adapter - I have one SFC pad on hand thankfully.

I've tried the adapter with a 2-player game, and it behaves exactly the same (i.e., I can get the gamepads to control the player 1, but not 2).

Just out of curiosity I've tried this adapter on my Famiclone, and again - same results. So, the console itself is probably working as intended.

[Great Hierophant]

Yeah, I got the compatibility backwards.

Remove the AV Famicom for a moment and look at the original Famicom.  That console had two hardwired controllers, I & II.  The button presses for each controller were readable in a serial fashion via a single bit at a specific memory location.  You read data for Controller 1 at memory address $4016, data bit 0 (D0) and data for Controller 2 (except the microphone) at memory address $4017, data bit 0.  That was the only way to read these controllers. 

The expansion port provided five extra data bits for peripherals.  Each bit can be used by a controller to send its button presses to the CPU, but programmers never supported more than two additional standard controllers in the Famicom.  A Famicom four player game will read Controller 3 from memory address $4016, data bit 1 (D1) and Controller 4 at memory address $4017, data bit 1.  That is pin 13 and pin 7 on the expansion port, respectively.

Most, but not all, Famicom games will let the player substitute Controller 3 for Controller 1 and Controller 4 for Controller 2 in 1-2 player games.  This was useful if your hardwired controllers were broken, worn out, too short or uncomfortable for your taste or you wanted to use a controller with turbo functions.  So in Super Mario Bros you can press A on Controller 1 or 3 to get Mario to jump. 

A light gun on the Famicom connects by the expansion port.  It requires two data signals, data bits 3 & 4, read at memory address $4017. 

Now, to return to the AV Famicom.   Controller Port 1 has a pin (lowest left) that connects to memory address $4016, data bit 0 and that is it.  The controller may no longer have been hardwired, but the data signal still was.  Similarly, Controller Port 2 only has a pin that connects to memory address $4017, data bit 0.  The expansion port's assignments were unchanged. 

In the NES, the two pins on the lower right of the controller ports bring the data lines needed for a light gun.  The AV Famicom leaves these pins unconnected, but it is simple to reconnect them by running wires from the expansion port, 

I would avoid using those aftermarket controllers in conjunction with official controllers.  While they work the same way, they may use a different silicon process for the chip inside the controller.

Actually, I can tell you right now that your adapter will not work as a Controller 4.  Your adapters' 15-pin connector has pins for pins 1, 4, 5 & 12-15.  This allows you to use Controller 3 or a Light Gun in either NES-style port.  You must have pins 7 & 9 connected for Controller 4 to work.

[yojc]

Well, I've checked the pinouts according to the NESDEV Expansion port page, and...

Code Select Expand

        .-
GND  -- |O\
OEJ1 <- |OO\ -- +5V
OUT0 <- |OO| <- N/A
J1D1 -> |OO| <- N/A
        '--'

        .-
GND  -- |O\
OEJ1 <- |OO\ -- +5V
OUT0 <- |OO| <- J2D3
J1D1 -> |OO| <- J2D4
        '--'
So, the both connectors are actually wired to the Player 3, and there's no way this adapter would work as advertised, right?

Bummer Especially since it was a neat adapter for Zapper as well...

The seller clearly stated that the adapter fully working and is suitable for playing games like Kunio with 4 players, and even noted that he can't test the adapter on Famiclones, which implies he must have tested it before putting it on sale. I wonder what he'll have to say.

There's just one thing I don't get, and makes me think I might be wrong still. Really, what is the point of this? Why would this adapter even have 2 connectors, if they both do pretty much the same?

[Great Hierophant]

I've seen that adapter before.  It could have been a perfect design with two additional wires.  Shame.

[yojc]

I have just received the refund. The seller really seems like a honest guy, dunno what went wrong here.

Well, I need a 4player adapter anyway, so I might as well try to build a custom one.
From what I've read, the Neo Geo extension cables are a good choice for the Famicom-end of the adapter: https://www.ebay.pl/itm/NEW-Durable-6-Foot-Controller-Joystick-Extension-cable-for-NEO-GEO-MVS-H14/382558508369
As for the joystick ports, I was just thinking about buying two extension cords for the NES: https://allegro.pl/przedluzacz-do-pada-od-konsoli-nes-i6687498840.html

This won't look a million dollars, but it should be feasible to build. Seems quite trivial on paper, actually. Am I right? Is there anything to be aware of?
I'm especially worried if these generic NES extension cables are Zapper-compatible.

[P]

I think it's probably OK. I used similar (or maybe same) extension cables and all pins are populated. You might want to ask the seller though. It's necessary to check with a multimeter if all the pins has wires, it's not enough that you can see metal pins in the ends.

Other than that the only thing to think about is that you get all the wiring right when you build it, I always manage to get things reversed when I build something like this.

[yojc]

Well, bollocks. It turns out they aren't Zapper compatible, as the required pins aren't connected. The seller stated they might not work so it's not that big of a surprise, but still.

I'm wondering if any of you had some luck using Zapper with these cables from Retrobit: https://www.ebay.pl/itm/Accessory-Extension-Cable-For-Original-Nintendo-NES-6ft-Retrobit/292696214187
I'd assume they should work with Zapper, as Retrobit sells their custom Zapper clones as well, but there are conflicting reviews on Amazon on that matter. I'd ask the seller, but eBay states that "due to the high volume of messages this seller receives, they are unable to respond yadda yadda".