Show HN: A game where you build a GPU
by Jaso1024 on 4/4/2026, 4:45:54 PM
Thought the resources for GPU arch were lacking, so here we are
Comments
by: rustybolt
This is great!<p>Some comments:<p>- I didn't like the "truth tables" one, I got many duplicate questions and for some reason I got only one second for the first question. The rest of the questions I managed to answer correctly but I still got only one start out of three?<p>- I got very confused by the capacitor. Capacitors do not have an "enable" gate! In fact, in 2.7 (1T1C) you are supposed to <i>build</i> the enable gate -- with a transistor. So currently, you can just simply not build the enable gate and use the one already in the primitive, meaning you don't need the NMOS gate at all.<p>Was this made using LLM-assistence? (Not judging, I'm just interested!) I'd love to hear more about your workflow and how you managed to produce a good UI as it's something I couldn't do if my life depended on it, and it's a skill I'd like to learn.
4/4/2026, 6:48:39 PM
by: txr
Anyone who likes this should also take a look at: <a href="https://store.steampowered.com/app/1444480/Turing_Complete/" rel="nofollow">https://store.steampowered.com/app/1444480/Turing_Complete/</a> At the end you have your own CPU with your own assembly language. Sadly stuck in early access since forever with some very rough edges
4/4/2026, 6:59:48 PM
by: roadbuster
I worked on deep sub-micron, full custom mixed-signal integrated circuits for more than a decade, and I can't pass the first level.<p>> Wire an NMOS transistor so that when In is 1, the output is pulled to ground (0). When In is 0, the output should be unconnected (Z).<p>Certainly:<p>(a) The nMOS has 3 connections: its drain is only connected to the output (no +Vdd supply), it's source is tied to ground, it's gate is tied to the signal input<p>(b) When the gate (input) is driven high, the nMOS transistor turns "on," connecting the output to the source (which is grounded). This acts as a "pull-down network"<p>(c) When the gate is driven low, the nMOS turns "off," leaving no connection to the output. This is equivalent to a "high-impedance" / "unconnected" / "Z" output<p>Fails 1/2 tests<p>(Edit) - I thought the light grey, thick line on the background grid was a wire from "input" to the transistor's gate. It is not. You need to explicitly add a wire from "input" to gate :\
4/4/2026, 6:54:19 PM
by: Elorth
Really glad to see this kind of game getting traction. I've been working on Hard Chip (a transistor-level CMOS circuit puzzle game) for a couple of years, and the niche is a bit lonely sometimes. Games that make low-level hardware concepts tangible seem to be finding an ever-larger audience every day. Excited to try your take on this with this one!
4/5/2026, 3:55:12 PM
by: p2detar
Well done. I enjoyed it and also found it interesting that the js was under 100k and served with br-encoding. I'm using gzip by default everywhere, but maybe should take a look at br for text-based content.
4/5/2026, 3:29:31 PM
by: Anonyneko
This looks really cool, although I personally seem to lack the absolute basic knowledge that is required to make sense of the tutorial messages, so I couldn't even figure out the first level.
4/4/2026, 5:53:26 PM
by: frmersdog
You need to have a, "Okay, I've tried 10 times, it's not working, what's the answer?" button. That will help not just us rubes who can't understand, but also in the off chance something is broken and even "correct" answers are being rejected.
4/4/2026, 7:21:01 PM
by: yuppiepuppie
Neat idea!<p>Ive added this to the HN Arcade! <a href="https://hnarcade.com/games/games/mvidia" rel="nofollow">https://hnarcade.com/games/games/mvidia</a>
4/4/2026, 7:29:12 PM
by: arcbyte
Seems cool but its just not quite responsive enough on Android Firefox. It seems to almost fit, but i think things are cut off. Controls dont seem to work - i think the materials are off screen because the directions say to select materials but I dont see where to do that.
4/5/2026, 1:40:44 PM
by: avipilcer
Really cool approach to teaching GPU architecture. The progression from basic logic gates to actual GPU components is exactly how I would want to learn this. Much better than reading datasheets.<p>One thing that would make it even stronger: a brief explanation panel for each level showing what real-world GPU component the puzzle maps to. When I completed the truth tables section, I wanted to know where that pattern shows up in actual silicon.
4/5/2026, 12:39:45 PM
by: everyos_
This seems really cool, haven't played it yet but I took a glance at the first two levels and it looks similar to another game I've played - will definitely play through it when I get a chance. I wanna make a GPU but my board doesn't have nearly ennough dsp units, so a virtual one like in this game will have to suffice lol
4/5/2026, 3:10:32 AM
by: dnotq
This reminds me of the Zachtronics game KOHCTPYKTOP (<a href="https://zachtronics.com/zach-like/" rel="nofollow">https://zachtronics.com/zach-like/</a>). The game left me wanting more and wishing I was using an actual tool for learning or designing semiconductors circuits, rather than playing a game.
4/5/2026, 2:51:38 AM
by: PotatoShadow
I was able to do the latch level (2.11) using a single OR gate. It did pass the tests, but I am not sure if what I did actually works in practice. (Force as one input, then feed the output of the OR gate into the other input) The fun fact after completing the level mentions a bistable latch (I don't know what that is) using two inverters, which I didn't use.
4/5/2026, 9:01:36 AM
by: mdtrooper
It sounds great, it remembers to me:<p>- <a href="https://www.nand2tetris.org/" rel="nofollow">https://www.nand2tetris.org/</a><p>- <a href="https://nandgame.com/" rel="nofollow">https://nandgame.com/</a>
4/4/2026, 11:00:41 PM
by: john_strinlai
as a learning resource, it would be great it acronyms were expanded at least once. nmos, pmos, gnd, vdd all in the first 5 seconds or so, and i didnt see anywhere that actually said what those stood for<p>otherwise, looks polished and fills in a nice niche!
4/4/2026, 5:57:52 PM
by: tankenmate
it's great, i really like it! i've been working on something similar for CPUs but not getting into the EE weeds (like i don't get into DRAM at all, no voltages, no slew rates, etc, etc).<p>it was all reasonably easy to get until you get to the sense amplifier which has an almost complete lack of explanation of why you need the required outputs, it is "clear if already known". i.e. if you've never done any electrical engineering it makes zero sense and is not the sort of thing a software developer could <i>ever</i> figure out with the minimal explanation.
4/5/2026, 12:18:54 PM
by: nc1zdev
Reminds me of that one data center game on steam. I love how we're gamifying learning on these levels now
4/5/2026, 1:46:15 PM
by: npinsker
Great game! For learning, might be nice to see some commentary or example (model) solutions after beating a level.
4/4/2026, 5:51:43 PM
by: dauertewigkeit
I really like the game as a concept, and I got pretty far already, level 2.16, but I feel like some levels aren't making much sense at all in terms of the goal and how the passing circuit fulfills the objective. The Latch and some others had me puzzled. Because it is clearly vibecoded I feel like I cannot really trust the educational material all that much and at times it's not clear if I am misundestanding something or if is just nonsensical LLM slop.
4/5/2026, 2:00:24 PM
by: Alexzoofficial
This is a fantastic way to make GPU architecture more accessible. I really like the hands-on approach to learning digital logic through a game format. Looking forward to seeing how the simulation system evolves!
4/5/2026, 9:21:56 AM
by: FrojoS
Awesome! Small feedback: The test should maybe auto run. I solved the first level and was confused why I didn't proceed. The out was -1 (but goal was z) and it took me a while to see the 'run test' button.
4/5/2026, 9:04:11 AM
by: xmprt
This is super cool but part of me wishes I could skip to the later levels rather than redo college homework from a decade ago. Maybe that ruins the fun but also slogging through the early levels (especially when the UI is a bit rough around the edges and doesn't support copy paste) isn't fun either.
4/4/2026, 8:15:50 PM
by: urba_
I love this! I learned my first logic with Crocodile Clips: would simulate and solder a lot of D flip flop based logic before learning about microcontrollers (my first was Atmel AT90S2313)
4/5/2026, 8:55:14 AM
by: Zetaphor
Please add OG/embed tags. It's both polite and helpful to let people see what they're about to land on when someone shares a link on socials/discord
4/5/2026, 2:25:01 AM
by: Jaso1024
Hi everyone, commenting to address feedback:<p>- Made timed minigames optional (e.g. binary tables)<p>- Added 7 (optional) intro levels to walk through pmos and nmos transistors<p>- Fixed the bug in the capacitor levels<p>- Changed editor bg to use dots instead of lines to fix wire confusion
4/4/2026, 7:43:52 PM
by: Insimwytim
+ for the idea<p>- for the load javascript from that page imposes on CPU. +15 °C in less than 30 seconds. Nothing on the page could justify that.
4/5/2026, 10:20:31 AM
by: vibe_that_works
That was great fun, an interactive refresher on my EE studies. Thank you so much for creating it.<p>If anybody can create something similarly interactive, educational and hands-on for microbiology or robotics, I am happy to sponsor your cost.
4/4/2026, 8:38:09 PM
by: dminik
Some feedback:<p>- Nice idea, though after playing Turing complete, I would like to skip the beginning and move to stuff that makes GPUs different to CPUs. But it's understandable.<p>- I'm not smart enough to intuit NAND from transistors. I'm also not sure I will be alone in that. It's such a weird difficulty wall.<p>- Speaking of, the difficulty is all over the place. Though easy mode is appreciated.<p>- Even with a n key rollover keyboard, I couldn't complete the capacitor refresh level. It seems like it speeds up and certain capacitors already start empty.<p>- The routing for wires is no good atrocious. Any level with more than 8 components will end up impossible to read.<p>- It doesn't help that you can't color code or even path wires manually.<p>- Might be Firefox only, but I had a hard time selecting the connection points.<p>- Dragging the mouse along the edge should pan. Otherwise you have to drop the connection and zoom.<p>- I appreciate the added "show solution". But it's not really giving you a solution. It's just a better hint.<p>- An option to show all tests or at least more tests would get great.
4/5/2026, 12:17:25 AM
by: unvalley
Great concept! Multi language support maybe good for spreading.
4/5/2026, 12:08:24 PM
by: DullJZ
Awesome! But too difficult for a beginner like me
4/5/2026, 12:42:13 PM
by: zapkyeskrill
Any easy way to make this usable on mobile? In portrait mode things are unreadable, zoom and scrolling do not work. Landscape is even worse as everything is out of view (and zoom/scroll do not work).
4/4/2026, 6:56:06 PM
by: BuildItBusk
This is amazing. There are a few quirks here and there, but the idea is great and it's super fun to play around in.
4/5/2026, 8:59:15 AM
by: eterm
Your bug submission endpoint is getting a 429, so I'll report a bug here:<p>I see a difficulty pop up after I click "run tests" but it then gets hidden and doesn't do anything.<p>This was after selecting intermediate on the truth tables level, then clicking "next level" from there.
4/5/2026, 12:52:45 AM
by: buildbot
This would be such a good game for introducing students to digital technology! This is so fun! We just had to draw them by hand back in the dark ages of the 2010s.
4/4/2026, 5:36:27 PM
by: msully4321
I am a huge sucker for games/lessons like this. I feel like I've played one every 5 years for the last almost 25 years.
4/5/2026, 6:30:38 AM
by: iandev
I'm confused about a difference in the NMOS and PMOS. The scenario I'm confused about is when the source is VDD and the drain is connected to GND and output.<p>For the PMOS, the output toggles between 1 and 0 (opposite the gate) as expected. However, for the NMOS, the output is always 0.<p>I don't understand why GND pulls VDD down to 0 for the NMOS, but not the PMOS.
4/4/2026, 7:50:24 PM
by: brynnbee
Huge fan of this! I love learning-by-doing and this captures that cycle perfectly.
4/4/2026, 9:26:52 PM
by: Liebmann5
I have been looking for something like this for so longggg! THANK YOU
4/4/2026, 11:30:34 PM
by: rg2004
I would have really liked to have a temporary node to test the outputs. Better than that, I would have liked to see the truth table update in real time without running the tests.
4/4/2026, 11:40:08 PM
by: fleshers
This is awesome! The truth table lightning round took me by surprise, I am rustier than I thought...<p>One note: It isn't immediately obvious that the In/Out nodes can be connected to multiple wires, made the first few rounds harder to work thru.
4/4/2026, 6:26:56 PM
by: ampedcast
It is really interesting. No authentication to save the level so that you can continue next time.
4/5/2026, 4:33:05 AM
by: gchadwick
A nice game, though the truth table lighting round is pretty punishing! Big contrast to the circuit building part where you can take your time. Personally I'd drop the time requirements from that quiz section.
4/4/2026, 7:17:12 PM
by: NooneAtAll3
if you solve a level, then press "next level", then solve that next level - then it still shows the original level (I think it just gets hidden below the new one and then reappears after a solve?)
4/4/2026, 7:31:10 PM
by: unsnap_biceps
The truth tables are way too hard for me. I need time to think and the 10 seconds is way too fast. If this is intended to be a teaching resource, avoid timers IMHO. It needlessly excludes people.
4/4/2026, 8:18:06 PM
by: xnzakg
The 2.13 level ("hex racer") is kind of pain. Apparently I'm not fast enough at dividing/multiplying by 16... when I get something like "convert 0xB3 to decimal"
4/4/2026, 8:00:20 PM
by: baobabKoodaa
Is this a sequel to "How to make a CPU"? <a href="https://www.youtube.com/watch?v=vuvckBQ1bME" rel="nofollow">https://www.youtube.com/watch?v=vuvckBQ1bME</a>
4/4/2026, 7:17:29 PM
by: Ginop
It's always nice to see educational games like that. A lot of new learners (like me) are just looking at the high level stuff, where the computer "just works"...<p>Well done and keep it up :)
4/4/2026, 5:57:06 PM
by: slake
Bro. I'm obsessed with this. I spent a good 2-2.5 hours on a trot with this. This was one of those things I always wanted to learn a lot about and this was just perfect for that. It wasn't that easy, I really struggled and gave up on some levels but came back and struggled through them. The HexRacer type levels are difficult and I wish I could skip through those.<p>Also when you give a solution, you probably need an explanation of why that works.<p>Can't wait till you add the additional coming soon levels.<p>Your feedback feature seems broken. I tried giving feedback about some basic bugs and it kept saying can't send message.<p>Please also add a waitlist to notify when you release the additional levels.
4/5/2026, 8:32:16 AM
by: arikrahman
Awesome project! Reminds me of Turing Complete on Steam.
4/4/2026, 5:19:31 PM
by: anderskaseorg
The “next level” button takes you to the next level even if you haven’t solved that level’s prerequisites.
4/4/2026, 7:46:13 PM
by: jmholla
The continue buttons in intro break for me all the time on Firefox. I can't actually finish most of them.
4/4/2026, 6:52:05 PM
by: Falell
Fun. 2.2 loads a blank screen for me, all previous levels were fine and 2.3 loads. Windows, Firefox 149.<p>Edit: Confirmed fixed.
4/4/2026, 5:46:31 PM
by: kongchu2
Soooo cool! I will keep try this
4/4/2026, 8:48:39 PM
by: K0IN
love it, some level (full adder with 8 inputs) where a bit repetative, but it is fun.
4/4/2026, 8:49:26 PM
by: triilman
is there any source or game like this specializing to create microcontroller, like arduino, wemos (not the IC), what kind of protocol is supposed to use.
4/5/2026, 1:07:41 AM
by: agrishin
Great project! I somehow missed whole cpu architecture topic, so gonna catch up on that now
4/4/2026, 5:35:38 PM
by: jomoho
first level is impossible to solve for me! Hint or showing solution did not work! Also adding multiple sources or ground behave differently than connecting to the same.
4/4/2026, 10:07:35 PM
by: oytis
Must be missing something - is there a way to save progress?
4/4/2026, 9:18:18 PM
by: hristov
Ok you have put a lot of work in this and it looks impressive. But it needs a serious balance change. It is far too hard. Currently this may work as a brain teaser for people in the industry or people with computer engineering degrees, but it wont bring any fresh young minds into the industry. The fresh young minds will be scared off.<p>Teaching is challenging stuff. You have to step out of your current mindset and think with the mind of someone that sees this stuff for the first time. It is not easy to make things look easy and simple. Specifically, I think you need a lot more exploration about cmos logic, about how one side pulls the output up or the other side pulls the output down but they are never on at the same time, about how they effectively amplify the result so the output does not have to depend on the power of the input, etc. Perhaps you can try to have people design things in NMOS logic than in PMOS logic and then combine the two to make a CMOS design to see how they complement each other.<p>But I do not want to discourage you. This is a very promising start and you should continue if you have the time.<p>Also, the timed answers -- are you kidding me? The time is waaay too short. And you fail all if you fail a single answer. Oh what is 0xDE in decimal, all I have to do is multiply 16 by 13 and add 14 to that. In my head in 12 seconds. Also the time is not sufficient for filling out truth tables, especially with a laptop trackpad. I was able to pass the truth tables, but gave up on hexracing.<p>Ok and here are some more specific issues.<p>-The wires seem to snap in position in a way that they superimpose each other so it becomes very difficult to see what your circuit is doing.<p>- truth tables seem to be bugged. If you have more inputs than the gate whose truth table you are looking at, sometimes it will generate a fictitious truth table with extra inputs. Thus, some times i get a NOT truth table that has two inputs.<p>- the ground element should have its connection circle on the top, not the bottom. I realized that you can rotate by pressing R, but the site does not mention that anywhere.
4/4/2026, 11:05:46 PM
by: schlecht_
Love it, thanks! Would you mind making it possible for me to see my "circuit" after running the tests? Currently, I can't go back to the circuit I created.
4/4/2026, 5:46:38 PM
by: joha4270
So, is there anything about GPU's in here right now?<p>I didn't actually finish Act 2, but it seems to end in a conventional processor with the GPU first coming after another two acts currently under construction.
4/4/2026, 7:51:50 PM
by: treelover
I like the concept! What tools did you use to build it?
4/4/2026, 6:22:33 PM
by: tithos
Cool concept, but it should be mobile friendly
4/4/2026, 5:58:56 PM
by: NooneAtAll3
truth table minigame is lmost unplayable in dark mode<p>also it kept showing the same table to me like 4 times
4/4/2026, 7:39:22 PM
by: nottorp
În a few years it will be the only way to explain the kids what a GPU is. Unless you work for an “AI” shop and sneak them into the data center.
4/4/2026, 5:12:53 PM
by: fragmede
Reminds me of <a href="http://nandgame.com" rel="nofollow">http://nandgame.com</a> and <a href="https://nand2tetris.org" rel="nofollow">https://nand2tetris.org</a>
4/4/2026, 7:25:08 PM
by: SilentM68
This is very cool!<p>We need more games like this so that the younger population get some sort of exposure to the hardware side of things, before AI takes over that field. I would also think that take-home electronic and soldering kits for adults and younger folks would be another way to reduce dependance on AI.
4/4/2026, 5:30:34 PM
by: lukebechtel
really fun :) thanks!
4/4/2026, 8:46:46 PM
by: NooneAtAll3
level 1.10 I put 2 AND gates and only one of them works...
4/4/2026, 7:45:23 PM
by: dcreater
Nice vibe coded project. There are a few UX holes i've encountered so far: No way to go to the next lesson if we dismiss the modal (have to go back to the tree and then click the next lesson)? more hints or step wise reveal if user gets stuck will be very helpful
4/4/2026, 11:44:19 PM
by: NooneAtAll3
how do I remove/delete elements?
4/4/2026, 7:27:08 PM
by: xyst
not able to get it to work on mobile
4/5/2026, 7:37:00 AM
by: skyskys
wow looks really cool, although seems kinda useless at first look.
4/4/2026, 6:13:38 PM
by: PunchyHamster
...why capacitor has 3 pins ?
4/4/2026, 7:52:15 PM
by: testaccount28
not playing past the truth tables bs
4/4/2026, 6:57:26 PM
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