There are days I look at the crap spread over my desk and think, man, I really have no idea what I'm doing in this hobby.

Then there are days I look at the tiny spiky hovercraft sculpture I've just willed and soldered into being, and think, man, I really have no idea what I'm doing, but this looks kinda pretty.

Lessons learned so far: The extra "hackable" pins need to be slightly further away from the Pro Micro footprint so they're easy to plug in to, and I need to put pin labels outboard as well.

What's going on here is pins 5, 6 and 7 on the Arduino, which are clock, latch and data for the NES socket, are also connected to channels 0, 2 and 4 on my logic analyser. Channel 6 (pin 10 on the Arduino) is just an extra line I can take high to trigger captures in PulseView.

Is this #NES controller busted or am I just doing something fabulously wrong? The data line just echoes whatever the latch line does, maybe suggesting the two are bridged somehow, but is this something a shift register might do in some circumstances?

Data line should only go high if I'm holding a button at an appropriate time in the clock line's cycles, I'm not holding anything in this capture but even if I do there's no change.

Data is just high the whole time without the pad plugged in.

The $10 pad arrived, and is pretty terrible: https://digipres.club/@timixretroplays/114296167646130444

It does work, though - here's my prototype program's output while I'm pressing A, Start and right on the D-pad.

I'm feeling confident enough about this project now to try ordering PCBs to match my 3D printed NES controller sockets.

I found a plugin for Rhino 3D that lets me export geometry to SVG, so I can print the exact outline of my 3D parts on the PCB very easily - how cool does this look!?

My NES breakout boards arrived - I've soldered one up with my 3D printed socket and I'm about to give it a go. Even if this doesn't work at all, it's still a good run of the process and I'm very happy with how it's gone and what I've learned.

The extra big hole in the corner is for an M3 screw to hold the 3D printed socket to the PCB, so yanking the controller's cord doesn't cause the socket itself to slip over and off the pins.

Um, okay - it works perfectly! This is a 3D printed socket I modeled in negative from the plug of a NES MAX controller, with 1.0mm PCB pins soldered to a breakout board of my own design.

It was a bit of a struggle to plug in this $10 repro controller - it was clearly designed for the tolerances of the original console's socket, which my breakout here does not at all have - but the dead MAX's plug slides on flawlessly.

Time to collect a *working* authentic NES controller and validate with that!

I ended up collecting a used NES-039, the new-style or dogbone controller, and that worked perfectly. I've since collected a Four Score as well, here's a thread on that: https://digipres.club/@timixretroplays/114494458860844483

It's now time to design and make a dual NES socket with matching breakout board to match this bad boy.

Unexpectedly, the socket pitch on a NES seems to be 19.5mm - I had fully expected it to be 20, since I've seen a lot of very neat metric measurements in these plugs and sockets already.

I know the spacing here will match the spacing on an original NES console because the Four Score can physically plug into itself - that wasn't just a silly thing to do for a funny photo.

Well, this is the first pass to replicate that geometry, anyway. I don't have time to 3D print this tonight, but that's the next step.

The two screw holes will be used to firmly mount this socket to the PCB.

The Four Score's double plug perfectly fits my 3D printed double socket. Next up is a circuit board to match.

The two plugs on that cable actually wiggle around slightly - it's clearly the same single-plug part in a different housing. So while I've measured the Four Score's sockets at 19.5mm apart, this plug would also certainly work on 20mm pitch sockets.

All of which makes me very keen to see what the NES Satellite's receiver plugs looks like.

And the PCB for this I actually designed last night, on the assumption my socket would fit. I'm choosing not-the-cheapest postage option this time because I'm sick of waiting weeks for projects to advance in between steps.

I've broken out the power, latch and clock signals in pairs so I can experiment with bridging them together - I'm fairly sure the original NES hardware had them all bridged, but maybe I'll discover a reason why it might be useful to page controllers separately at some point.

Five boards ordered on Tuesday, arrived on Monday - not bad for AU$20-ish. Would probably have been here last week if I hadn't opted for black PCBs out of vanity - I might just leave prototyping stuff to the default green in future, which apparently is quicker to turn around.

Anyway. My dual NES socket breakouts have arrived - they'll be a little work to fully assemble and solder up, but they look glorious so far!

First time trying this out. I originally thought I'd be putting the pins into the back of the 3D printed socket and slotting that assembly onto the circuit board, but the fit between the pins and those holes is so precise I had to carefully line them up and pop them into the PCB one by one. I'll be printing a little tool to make doing this by hand easier in future.

The socket screws to the PCB in two places for maximum stability and to stop NES pads from yanking it off the board if they stick.

I have had to partially break it back down again to make it work on my little board soldering attachment. The exact order of operations for assembly is a work in progress.

Again, this is just my little remix of @rasterweb's little soldering board: https://www.printables.com/model/598207-prodoehls-solder-board-v2

Looks like I'll need to make a bigger one to do stuff like this in one go!

And finally, the whole shebang - an #Arduino Pro Micro clone, my own custom dual #NES controller breakout with a #3DPrinting socket, and the #nanoDLA logic analyser ready to help me learn how to talk to a NES Four Score - and later, to help document how to do the same with a NES Satellite!

This is the confluence of a decade plus of hobby learning and making.

A note mainly for myself: CLK and LAT are pins 5 and 6, and channels 0 and 1; P1D0 is pin 7 and channel 2, P2D0 is pin 8 and channel 3.

The straight-through NES sockets have arrived from AliExpress. They are very clearly using the exact same shell as the 90-degree ones, just with straight pins instead of bent ones.

Unfortunately, while the 1mm pins in these connectors would individually fit the 1.1mm through-holes in my breakout board, they won't do so all together - so I'll need to order a separate version of this breakout board to test off-the-shelf sockets like this. That might work better for my 3D printed sockets, too.

With 1.2mm holes, and the extra pins clipped off, the AliExpress NES sockets sit comfortably and snugly in my prototype breakout, with the correct spacing for a Four Score's double plug. This project is now waiting on the arrival of my NES Satellite to validate that plug fitting as well (I think it's more rigid than the FS's so less room for error).

This might be the end of the road for my 3D printed socket, just for now - I'll focus on the better quality outcome for the V1.0 #NES breakout.

My #NES Satellite has arrived - and what a beautiful chonker of vintage tech it is. The entire right half of it is just space for *six* C-cells. Tapping the side of this thing makes it ring like a bell due to all the giant springs in the battery bay.

It looks like my dual NES breakout needs its sockets about half a millimetre closer together - this would make the connector pitch 19mm, vs the 19.5mm I measured on the Four Score. I'll order another board to test this.

Soldering to pins on a 4mm pitch is actually kinda zen. I'm really pleased with my consistency there.

In other news, turns out a 19mm pitch between connectors feels perfect for both the Four Score and the Satellite. I think this is the final version of my dual NES breakout, unless coding for controllers reveals some terribly incorrect assumption.

And here's my setup for implementing and testing support for controllers on the Four Score.

Latch (yellow) is pin 15, ch 7.
Clock (green) is 14, ch 5.
Port 1 data (blue) is 16, ch 3.
Port 2 data (blue) is 10, ch 1.

Purple (pin 9, channel 0) is so I can trigger an interrupt for the logic analyser - I can take that line high, wait for the analyser to notice and start capturing, then start flicking latch and clock to grab data.

Tonight's result. This is a #NES controller plugged into the 4th port on a Four Score, with Up and Right held down - that's the first two dips in P2D0 in the screenshot.

The dips in P2D0 and P1D0 at the 18th and 19th clock pulses respectively represent the signature of a Four Score, exactly as described here: https://www.nesdev.org/wiki/Four_player_adapters#Four_Score

And see that very short section below, about the NES Satellite, where it says "specific details are not yet known"?

That's this weekend's mission.

#retrogaming

I did plug my Satellite's receiver into this contraption and run the logic analyser capture again, but not much happened - both data lines were held low, which was interesting, but there were no ID pulses like I saw with the Four Score. Possibly the Satellite does something different entirely, or only produces output when it's got a connection to the transmitter.

I bought this Satellite specifically because the seller said it was tested working, so I'm not expecting to find I bought a dud.

I'm home sick today, and this stuff is all still set up on my desk, so I'm asking the question: What did the 2/4 switch on the Four Score actually do?

The manual just says to switch it to "2" if you have one or two players, or "4" for three or four. But it doesn't actually explain why, or what the consequences might have been if you got it wrong.

The troubleshooting table says if the game can't be controlled, the switch might be in the wrong setting. Time to find out what that means, exactly.

Oh, okay. If you flick the switch to "2", it just passes ports 1 and 2 straight through to the console, and ignores 3 and 4 entirely, bypassing the Four Score's logic and protocol.

That'll be for compatibility - according to the manual, the Four Score only works with the original controller, the MAX pad and the Advantage joystick, so if you wanted to plug a light gun or dance pad into the Four Score, it has to be in passthrough mode.

The NES Satellite has a "Mode Switch" that's labeled CTLR/GUN on the unit itself, and the manual says it has to be in the GUN position for the NES Zapper to work. I bet it's identical to the 2/4 switch on the Four Score, and just dumbly passes through inputs on the first two ports.

It'll be interesting to see how the wireless comms work. Does the Satellite receiver itself flick the latch and clock signals for the four ports? How are they encoded into IR LED blinks? That's a question for later.

Did you know AA batteries are the same length as C ones? This cursed fact means you can 3D print simple adapters to install one in the others' place - and it meant not buying AU$17 of batteries I'll use a handful of times, ever, or waiting for cheaper ones to be mailed to me.

It was not fun getting them in there, and don't ask why the 3D printed parts are so shocking, but my NES Satellite lives!

And yup, it works. Screenshot shows me pressing up and A on the controller plugged into port 1 of my Satellite.

This is probably the first time in decades anyone's looked at data coming from a NES Satellite this way, and... it's not quite what I expected. No signature blips like the Four Score, the data lines just kinda die after the 24th-ish clock pulse without ceremony.

Ok, so:

- with one or zero controllers plugged in, both data lines go high for 24 ticks. Player 1 input works entirely as expected, except that holding right (the last bit transmitted) leaves D0 low, like it's not expecting any more bits on that line (from, say, P3).

- With a pad in port 2, P2D0 drops after eight ticks, so it's detecting there's something there.

- In no case do I see inputs from pads in P3 or P4. I thought it might need tighter ticks, but that hasn't made them appear.

- It behaves the same way regardless of whether the mode switch is on CTLR or GUN. I think I need a Zapper now to test if there's any difference and if this switch even works.

- Maybe it's like SEGA's 6-button protocol, and flicking the latch again within a frame will page across to P3/4 input?

- Two of the top ten google results for "nes satellite protocol" are posts I've made in this thread. I've @foone'd myself.

The manual (https://archive.org/details/NESManuals/NES%20Satellite/page/n1/mode/2up) does say that "the NES operates differently in the three or four-player mode than in the one or two-player mode. Because of this, you should only plug in the necessary controller(s) for the game you are playing". Also that the Zapper (in GUN mode) and the Power Pad only work in port 2. So it's detecting what's plugged into #2 in case it's a Power Pad.

It does not describe *how* it acts differently in 3/4 player mode, or what might trigger that.