 Did you know that you can overclock a graphing calculator for fun and profit? Yeah, so we called up Texas Instruments and we're like, hey guys, can you send us some calculators to overclock? So they sent us this one, which This doesn't look like a calculator like it does. That looks exactly like a calculator. What are you talking about? But it doesn't look like the calculator. No, it's not the calculator. So we actually had to go digging through Alex's sentimental drawer where we found the very TI 84 plus that got him most of the way through engineering school and also most of this job. So I guess what you're trying to say is you'd like for us to not break it. Yes. Well, good luck with that. Xsplit makes powerful streaming PC apps for streamers, vloggers, and more. Check out their VCan app to change or blur your background without a green screen. Learn more at the end of the video. Before we go any further, we should probably address why anyone would want to overclock a graphing calculator. Now one obvious reason is that when you enter a more complex function in them, they can actually take a hot minute to spit out the results, but there are some even more fun and geekier reasons than that. Doom. Playing Doom on your calculator in class. Turns out that's a thing you can do and the more you overclock it, the faster it'll run. Of course to quantify the benefit of our experiment here, we're going to have to set a baseline. So let's get Doom installed on this puppy and see how she runs. All right, so in order to get programs on your calculator, you just get TI Connect. It has not changed since I used it in high school. Go to send to device. All right, so calculator overclocking. In here we have Doom 2 runs a bit better. So let's toss that on. Wow, that animation, I remember the pages and when you deleted things how the page would just Oh my gosh. Yeah, this is pretty slow to render new frames. Oh, I think I got a new guy. Oh pistol. Bang, bang, bang, bang, bang. Hey back up before he fires. Oh, he hit me. Yeah, these frames render a little on the slow side. I can see how this experience could be enhanced with a faster calculator. That's it, eh? That's the brain. Yep. We need to find out how much power it's drawing so that you know, you can't design a thermal system without knowing how much power you're drawing. So first thing we need to do is power it. That's flux. You're just going to solder leads to it. Positive and negative. Let's tin some wires here, suckas. This is nice. Normally they don't let me use the soldering iron. Well, oh, yeah, the soldering that's coming in a bit you are not doing. You can do this one. Like look at the landing pad. You're not doing the harder ones. Look at this that I did this morning. That is pretty impressive. Yeah. Assuming that it actually still works. I have no clue. Okay. So let's see if I did it right. Hey, it's alive. Yay. He was a little nervous. I saw him. Okay, so I was slightly concerned about this. Uh, it's drawing so little power that it's not registering on our power supply here. Yes. So we're gonna have to calculate it a different way. One moment. So all we need to do is hook up to our multimeter, which should tell us how much current we're drawing. 0.001 amps. Can you change the range and see if we can get that a bit more precise? No. You know what though? I bet what we could do is actually do something on the calculator. So I'm going to take that from you and I'll sanitize my hands after. And then you do something. Like run Doom, for example. Okay, so we're gonna graph now. Oh, yeah. 0.013 is the max. 0.091 watts of heat to dissipate for the total thing, including the display. So 0.1 watts. Yeah, I think we got this. And we're taking this one step further. What do you think? One step further. What do you think the temperature is gonna be? 20-25 degrees. I was thinking 24 and a half. It's heating up boys. I can see it. It's integrating now. You got the 24.5? 24.5. I saw it. 24.6! Yeah! I win! Meaningless victory! Only if you round though. I was closer. Dang it. Now that we have our baseline, what do we need to overclock this thing? As you can imagine, there isn't exactly a bios that you can go into and change the multiplier. A wild Anthony appears. In our calculator and many older electronics, the CPU speed is regulated by a resistor capacitor or RC oscillator. We'll be simplifying a bit here. So if you want a bit more of a complete explanation, go ahead and watch this excellent video from Ben Eater. Basically, how an RC oscillator works is you use a transistor or an op amp to compare the voltage between this capacitor and some voltages we set. So when the voltage of the capacitor is below a certain threshold, power is applied and then it is removed once it hits that threshold, creating an oscillating motion, which gives us the clock of our CPU. To overclock, in that case, all we need to do is swap this resistor out to change the threshold, which gives us a much faster rise and fall. We're going to use that with our TI-84 to increase our clock speeds. That sounds easy enough until you see the size of the resistors that we're dealing with. We need to replace R07D and R08D. So these are the two right here. And as you can probably tell by how massive these tweezers look, they are super tiny and I am not excited about this. Now this is the part that has the greatest risk of just completely killing everything. So I'm going to have to use the hot air gun while pulling on the resistor and hope that the resistor that I want to come off comes off and no other bits do. If I slip then I might destroy it. It worked. I got it off. Right there. Those are the pads that I have to land the solder on. And this is the size of the resistor. In theory, we should be able to overclock it with just swapping one. So what about we only swap one? See if it works. And then we can swap two and we'll have a larger range of potential overclocking. After the cameras turned off last night, I kept on working on this. We had a bit of a problem. You know how like you tried it as well. Yep. Yep. Nothing was sticking to the pads. Turns out they were gone. Yeah, totally gone. No pads at all. Ripped them right off. Fortunately, there's another resistor right next to it that happens to be wired up in parallel. So we were able to solder on to that one, attach the potentiometer and overclocking works now? Yeah, it works. It's not 100% stable at the moment. Oh, that's overclocking for you. Yeah, and I think that the reason for that is that like it needs water cooling. It needs water cooling and also like it's a resistor capacitor thing that makes this whole clock circuit work. Yeah. And with these long leads here, we're adding capacitance. So when we shorten these to like their final length, Got it. It should be a lot better. To make sure I understand properly, it is your intention to continue using this calculator in its water-cooled overclocked state, correct? Oh, yeah. It's like it's my calculator and it's not going to be maybe the coolest calculator in the world. Then I'll be building the most ridiculous water cooling loop you ever did see. Absolutely perfect. Would you look at that? Final block assembly. Here we go. We're also going to have to make these leads shorter and the other thicker leads much shorter. How short do you want it? Let's not make it much shorter so that we can shorten it later when we know how long it needs to be exactly. This is the overclocking dial. You better not bump that too far by accident. A bump will be like 300 megahertz. How are we going to solder it on even? What do you mean? Well, it's going to have to be long enough that we can get at it before we close it. Okay, we shouldn't have to straighten it. We shouldn't have cut it. We should have just... Yeah, we probably shouldn't have cut it. I knew it. I had such a bad feeling about it. Well, that's quite a good tape job. Thank you. Thank you, Linus. If anything was going to go horribly wrong, it already would have. Yeah, you better do that. You better find the hardest wood possible. Knock on it for days. I think this RGB reservoir sphere might be the most German thing I've ever filled with water. Well, I forgot that you had the CPU block and these tubes were just open on the table and I was sitting here filling the reservoir. Real focused on doing a great job of pouring and the table is covered in water now. The good news is I think I've got a better idea for how to fill it now. Oh, just left it there. Look at the block size compared to what we're actually cooling. That is about as riced out as a calculator could be. Oh, there we go. It's definitely working now. Hi. Oh, there you go. Is it actually circulating water in there though? Doesn't look like it. Well, we better go fast. We don't want it to overheat while there's no water flow. Water's coming through. Oh, okay. Good enough. This thing's horrible. Don't buy it. She did it! Yes! We have a water-cooled calculator. We do. Yep. Absolutely amazing. You know the funny thing is we're gonna go and play Doom again and it took so long to get this done. I'm not gonna remember if there's any difference. I don't make... This might actually be running faster. Oh, it definitely is. It's actually like noticeably faster. This like dramatically, it's like a very nice thing. It like dramatically exceeds my expectations. Look at this. Like I can actually kind of move around. That's crazy. Because that difference is from 16 to 18.7 MHz. We can try and get just a tiny bit more and see what it's like. Doing a live speed increase. Is it still running? Yep. Okay, let's just try and get a little bit further. Oh yeah, it's faster. It's faster loading that map there, son. Woo! Look at her go! Let's take it just a tiny bit further. Let's see when it becomes unstable. Wow, look how quickly it's loading now. Oh yeah. That's... Like this is a big difference. It seems to be taking it. Let's just push it until it's, you know, not stable anymore. These are basically loading pretty much instantly. Wow! 26.8 MHz! Damn! So the reason why it's getting so garbled is definitely because... It's not stable. It's not stable then. Also, it's like the flash for some of the cycles is just not there. 26 MHz. That's a whole 10 MHz faster than before. 10 million Hz. If you guys enjoyed this video, you might also enjoy the series where Alex and I go through the grueling process of water cooling a red 8K camera. That one was very frustrating, but as long as it's entertaining for you guys, it's totally worth it, right? Yeah. Right. I wasn't sure what he was going to say. I'd like to thank everyone that helped us out on this, particularly the people on the Chemtech forums. RS Barges, aka Dr. Denar, and Christopher Michael, aka Kerm Martin. Also, Virtual FlatCAD for the SICK TI-84 model, and of course, TEX Instruments for the calculators that we didn't end up using. But they still sent them. It was nice. Thanks to XSplit for sponsoring today's video. XSplit's V-Cam can remove, replace, and blur your background without a green screen. It works with any webcam, and there's no need for complicated lighting setups. It uses AI to automatically know the difference between you and your background, and you can customize the background to pretty much anything you want. V-Cam works with other XSplit broadcast tools, but also OBS, Slack, Skype, and more. They've got 24-7 support and lifetime updates, and it costs as little as $9.95 USD for a 3-month license, or you can get a lifetime license for $40. Use offer code LINUSTECHTIPS to get 10% off at the link in the video description. I'm very happy about this. It's my new favorite thing. You know what you should totally do is pull that stupid manufacturer's water-cooled RAM, where it just has water in it, and just put plugs in it, and just fill the block with water. Oh yeah, that was my plan. Oh nice, I love it.