 I have a new games console. This is it. It's a NES on a chip handheld gaming device. They are incredibly cheap and utterly ubiquitous. They're based around a re-implementation of the Nintendo Entertainment System as a single blob chip. They typically come with a million pirated NES ROMs and weird ROM hacks. They're actually pretty good for what they are. The NES implementation is decent. They play games pretty well. This has got a good battery, an excellent screen. The controls are kind of terrible. It does composite video out. It's actually a reasonable device for what you get, particularly for the price. But I'm not interested in that. I'm interested in this. This is the Player 2 gamepad, which plugs in the top. And certain games will allow you to use it as the second player. It'll allow you to have two people playing at once. And it does actually work. I am the top player in this one. The gamepad is vile and spongy and generally horrible in every possible way. But it does actually work. It connects via USB, except of course they put the wrong plug on the end. So let's get rid of these things. I'm not going to talk about it. And let's talk about this. Because I have a new Amiga. And Amigas need joysticks in order to play games. I have a joystick for mine, but I hate joysticks. I'd much rather use a gamepad. And here I have a cheap and nasty gamepad for a system which I never use. So let's try to turn this into an Amiga gamepad. So I'm just going to quickly take the back off and show you what's inside. So we take the lid off. And this reveals a single PCB with some contacts on it. A, well, let's get the right way up, OK? A conductive rubber mat, which has got pads here. When you press the button, it pushes the pad down onto the contact. So this goes roughly here. So pressing one of these things closes the switch. And here we have hard plastic pieces that the user actually presses. And this in turn presses the rubber mat. Now this is USB. So the USB cable is connected to the contact here via this, which is a blob. It's a chip on board. The silicon chip is bonded directly to the PCB and then covered in this black resin to protect it. It's the cheapest and nastiest way of getting a chip on a PCB. The Amiga uses a parallel system for its joysticks and mice. I've got here the Amiga mouse. And here is the connector for it, which is a completely standard 9-pin sub-D connector. These wires, if it were a joystick, four of the connections would be for the four D-pad directions up, down, left, and right. There's two for the buttons, button A and button B. You've got five volt and ground and a couple spare. So to turn this into an Amiga game pad, basically all we need to do is to disconnect the blob, connect five volt from the sub-D connector to the common side of all these switches, which is this big pad here, which you can see extends around to all the various sets of switches. Then we connect the other ends to the appropriate wires in the sub-D connector and profit. So let's give this a try. Now, in order to connect this to the Amiga, I do need something that will plug into the game port on the Amiga. Luckily, I've got here a 9-pin serial cable. This is just a simple straight-through cable. So one pin from here is connected directly to one pin from here. So it won't care that there's not been connected to serial. I can plug this end into the Amiga, and then I can plug this end into a 9-pin female connector, which I can mount on the side of the game pad. So this means that we don't actually need to solder up a cable, which is nice. We do need a way to get this mounted into the game pad itself, which will probably go here-ish. And we do need a way to wire up and modify this PCB. So what I'm going to do first is just do a little bit of mapping. However, I think that because this wire is being annoying, let us just quickly remove that. So I'm going to unsolder it. Come on, this is hot. I'm sure this cable will come in useful one of these years. So we can get rid of that completely. Because what I want to do is just make sure that all the switches are using the same common ground. So the continuity tester is working. So this obviously connects to here. Does it connect to one of these? No, it doesn't. It doesn't connect. It's a little bit weird, actually. That's not ground. This is ground. This is connected to here, here, here, here, here, here, here, and here. Now these two buttons, marked TA and TB, are a little bit different. They are turbo buttons. The NES only had two buttons, which is A and B. So TA and TB actually produce repeated presses suitable for shoot-em-ups. So they're wired up a bit differently. OK, so they are not connected to the common ground. That's fine. It'd be nice to turn this into another B button, to be honest. So we've got our common ground ends up here. That's a nice big pad. OK, I've used a sharp tool to scrape through the tracks here, which isolates the USB chip completely. It's still connected to its terminals here. But as they aren't going to be connected to anything, the chip should now be completely dead. We could, if we wanted, scrape it off the board. I now need to think about where to solder our wires on. The obvious place to do that are these test pads, because they don't have any solder masking, but they are underneath the rubber mat. Now we might be able to get away with it, given that the important part is the conductive bit here, which needs to press onto the middle of the interleaved tracks. But I would rather not. For cases like this one, as you see, the track actually runs here to the chip. So there isn't really any space other than over here. We could solder on a wire here, but it looks a little bit tricky. Let's just give that a try just to see what it's like. So we gently scrape off the solder mask like so. And then grab the soldering iron and just see if we can put a bit of solder onto it. Is it going to stick poorly? But it is sticking. OK, and let's put the meter back into continuity mode. Do we actually have electrical connection? Yes, we do. And how is that on the rubber mat? So our piece of solder is under there. I think that's OK actually. So let's grab some wire and see if I can get a piece of wire attached to that. So here is a small piece of wire or rather a large piece of small wire. So let's try to tin the end. What would be great for this is magnet wire, but I don't have any. Magnet wire is solid core copper wire that's been coated with an insulating enamel which burns off when you apply solder. So it is both very thin and quite easy to work with because you can just solder a bit of it onto things and it just works. Yeah, that was no trouble. Right, so let's now try this piece. This is for the right pad. So again, we scrape off the solder mask. And in fact, while we're at it, I'll do the other. Pads to so this one is left. So you see it connects here. So this one is up and is rather thin. Here is ground or five volts. I need to go look up. What connection needs to be made, to be honest. And so we've done right. Down. Left. And up. OK. So let's go over this side. And we've got B and A. OK, now let's see if we can get solder on these. This one. OK, that does actually seem to be working. And here is not the right solder joint. It's a little bit of silver on the track. I think these two need a bit more work. I don't want to scrape too much or I will take the incredibly thin and cheap copper off completely. Yeah, I can just see it wicking down onto the track. So I think that's working. That's better. OK, so we've got some orange wire for that direction. Let's just have just going to cut some lengths of other colours. So you've got purple, red, white, yellow, green. So let's go with black as the common. So we tin the wire poorly at not my best joint, but it does seem to work. Let's do the connections, the directions, rather. That's good, giving the wires a bit of a tug just to make sure they are firmly attached. This one goes here. I think I may have slightly screwed this one up. No, that's fine. I just need to make sure that the wires don't end up running underneath the rubber mat. I do have a plan for getting rid of the rubber mat completely, but let's see if we can get this to work first. That is not sticking down. So we now have one more directional wire. I'll use another colour for that. OK, that's much better. So let's just route all these north and see what the map does when we put that back on. Yeah, no problem. OK, and now we have A and B. That was my multimeter turning itself off. Those all seem like decent joints. This last one. Oh, yeah, I need to tin it. Good. OK. So let's just reassemble things. This is the bottom, so let's put the. Let's go this way around. So the plastic buttons go into place. Then we put the rubber mat in. Then the PCB, just making sure that I have actually sort of wired up the right pads like so. The big bundle of wires can, for now, go out the hole. Don't think it matters which way up this goes on. It does, but this is the right way. OK, so this feels just as bad as it ever did, which is right. OK, so let's just bear a couple of these and do some testing. OK, so that should be hooked up to one of the buttons. That can lose. OK, so let's go black to black purple to purple. I hate that. Yes, yes. Let's investigate Plan B. Plan B might be easy. It might not. OK. Give me a second. OK, so Plan B involves these. These are microswitches. I've got three different sizes. These are the big ones. These are going to be too big for this use case. So put these back in the bag and put them aside. But I've also got these, which are much smaller. This is the thinnest. It's a simple inverting fingermajig switch. I can't remember what they're called. Castanet switches. And but they are about a millimeter thick. But I've also got these, which are significantly more robust. These are about two millimeters thick. Now, my thought was that I can simply solder these across the contact pads like this so that now we either have the plastic button pieces. These push directly onto one of these switches. Or now I'm thinking we could leave the rubber mat and have the rubber mat push these. Yes, I think that is preferable. So is it across? Is it this way? I think it's this way. Yes, it is. So here we have the two interlaced sets of tracks. We want this to go in the middle. So if we we will fit very neatly in the middle, set diagonally so that it connects from here to here. OK, let's put this on. So we put a blob of solder here. I said a blob of solder here. The switch then sits diagonally. I think this is going to need tweezers. Like this. We want it to be in the middle, but with one pad sitting on top of that solder blob, like so, it keeps falling off. OK, that's not really the middle. Let's see if we can adjust that a little. We'll do so we now solder this side on like so and reassemble. So it's now nice and clicky. It's much more positive. So let's just try the continuity test again. So we want this one and this one. That feels great, actually. It's quite loud. If I lift it up a bit, it's still just as loud, but way more positive. Yep. OK, I like that. Let's do the others. So back with the probes. And let's do some testing. Good. OK, I'll do the rest in a bit. Just thinking about the A and B buttons. If I want to turn this into an A button, I need to connect from here to here. This is the signal for A. No, I want to turn this into a B button. So that's awkward, actually, because it's connected from the signal from A to something else. So I think that we need to cut. No, we can't cut here or disconnect A because that's connected up there. I don't think we can to easily turn this into an A button. So the way it's set up is A here and B here. I was wanting A here and another B here so that you can use it this way around, which is the way I'm used to for the N64 style layout. So I could cut to here. OK, that is no longer connected. So if we connect this to ground, that's this pad here, then this can become another B signal, which is here. So we want to connect a wire there and a wire there. OK, so let's open this up. This is our ground. So that's going to go over to here. OK. And we've got a handy pad here for B, which is going to go to here where there is also a handy pad. Right, let's get a few lengths of simple wire. We don't have to worry about the rubber mat anymore, of course. OK, so this solders on here and we want to cut it about there. OK, now we strip this end. That will go here. And this then needs to curve around. Let's put that here. Sorry, it keeps drifting on camera off camera like so. OK, so now if we take the probes and stick them here, that is across B and press this, either button works, fabulous. The other thing we could do is since this is ground is to stick a piece of wire from here to here that would make this into an A. Yeah, why not? Since we're here goes to there needs more solder to there. Right, and now if we test these probes, we should be able to press this one or this one. But these do something else. Excellent. I think that bit's done now. So let's reassemble that and see how it feels. Hey, what have we got? They're a bit spongy, recently clicky. That doesn't feel quite right. Let's just do the backup, which will make all the tensions even. It's possible that I haven't put them properly in the middle. That will cause problems as I'm relying on the rubber mat to the middle of the rubber mat, the hard, conductive bit to press the center of the switches. There's a little stud sticking up in the middle of each switch. OK, that's not very good, actually. The tension on each one is very different. Also, I am not convinced by the squishy rubber mat. So let me just try that with the mat removed completely. I think this is not going to work very well with the mat removed, but I'm going to give it a try anyway. OK, well, it's very rattling, as you might expect. The deep pad doesn't work at all. I think, actually, the PCB is not so it's designed inside to have the rubber mat in place. So I think the PCB is not being held tightly against the switches. So I've actually hold that in place myself. These buttons work, but these ones don't. Now, I know why, which is that these buttons have the round thing in the middle that pushes up against the the actual studs in the middle of each switch, but these don't. So this is supposed to go on like so in order to push the switches. You actually have to press quite hard, which isn't brilliant. They do actually seem to be roughly in the middle. This switch here has a solder spur sticking out, which may be why it feels a little bit different. So let's just get rid of that better, I think. OK, let's just put the rubber mat back on. I think that is better than without it. It's an interesting experiment. One thing that might be worth doing is adding plastic pieces to the deep pad itself to push against the studs. That's quite feasible. I can either bodge it up or attempt to 3D print something. But I think this is electrically working. So let's just leave this for now. OK. So I think this is most of the game pad itself. The next stage is to wire it up to the Amiga. It's not quite as straightforward as I originally posited because you've got to push way too hard to make the deep pad work. It needs to be more sensitive. It needs a shim of some kind, also with these buttons. This button is much more sensitive than this one. These two are all right. Yeah, this is going to need some careful tuning and shimming. Yes, the Amiga. So what I'm going to do is the sub nine connector is going to go in a hole here, which I'll have to cut. Then this. All right, I've lost the sub nine connector. There it goes. So that will fit in in there. This will then plug into it. This end plugs into the Amiga. Unfortunately, the Amiga is rather cramped on space. This has these two wings with the screw terminals in it that fasten the connector into the socket. The Amiga doesn't have those. I'm going to have to chop them off to make this narrower. So that will be exciting. So I'm going to leave it for now and come back next time and try and do that.