Show HN: A game where you build a GPU

(jaso1024.com)

285 points | by Jaso1024 3 hours ago

42 comments

  • roadbuster 1 hour ago
    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.

    > 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).

    Certainly:

    (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

    (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"

    (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

    Fails 1/2 tests

    (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 :\

    • mistidoi 1 hour ago
      I'm a total doofus with no relevant experience and neither could I.
      • Jaso1024 1 hour ago
        Adding intro levels today!
    • Jaso1024 1 hour ago
      lol, mb. As in understand it, its that the colors of the bg make it seem like its wires when its not, I'll change the color theme a bit to fix (plz correct me if my understanding is wrong)
      • roadbuster 1 hour ago
        Yes, that's the issue: the (thick) solid grey "major axis" lines on the background seemed to be a wire.

        If I could make a recommendation, get rid of the grid lines entirely and only have 'dots' at regular spacing. Here's what Cadence Virtuoso looks like (the most popular circuit schematic tool for integrated circuit design):

        https://www.eecs.umich.edu/courses/eecs311/f09/tutorials/cad...

        • Jaso1024 55 minutes ago
          Will do, thx! Coming in the next push
  • xmprt 8 minutes ago
    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.
  • rustybolt 1 hour ago
    This is great!

    Some comments:

    - 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?

    - I got very confused by the capacitor. Capacitors do not have an "enable" gate! In fact, in 2.7 (1T1C) you are supposed to build 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.

    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.

    • Jaso1024 1 hour ago
      Oh, I didn't notice this capacitor bug, I changed it to add an enable gate for 2.4 (for context, i created 2.4 after 2.7 b/c i thought 2.7 wasn't obvious enough for some ppl). 2.4 kind of needs the enable pin b/c of how my simulation system works. Yeah, I felt pretty conflicted on the capacitors whilst building, theres actually a note about this in the capacitor info block in later levels, but I couldn't really make a true capacitor compatible with the underlying simulation system I had built (I should have thought it through from the start).

      Ill fix the truth tables bug (i think i know the issue), the stars come from playing in endless mode

      I used claude quite a bit, it struggled through a lot of this (wiring and simulation systems in particular), but managed to crank this out, for the graphics i was extremely detailed in terms of what i wanted i'd say

      • tuetuopay 1 hour ago
        Since we're in feedback mode, 2.16 has no BitLineBar reference to feed to the comparators. I had to cheese the level by connecting the "capacitor" outputs straight to the outputs, and it worked.

        On the capacitor though, the capacitor level is weird as you don't build the capacitor charge system with transistors. Though I definitely get that the simulation engine is for digital stuff, not analog :)

        Also a general feedback on the time-based challenges: dial them back. A lot. Most of them are just not interesting and have zero learning value. In fact, the "DRAM refresh" one just made me quit the game (clicking on 8 rows to keep them fresh). Okay, 10s is enough, I got the point. No need to hold up for a whole minute. Kinda same for the hex one. However, some of them are good, and the UI for the binary ones is great, especially for the two's complement one!

        Small nitpick on the UI: some blocks don't have their connections aligned with the grid, making the wiring OCD-incompatible. But that's minor. It's a shame since the wire routing algorithm works quite well overall, and I'm impressed an LLM could produce that good of an UI!

        Otherwise, quite a fun little game, if slow paced when one already knows some bits of digital logic. Keep up!

        • Jaso1024 57 minutes ago
          lol, I encountered the same thing w/ the Dram one in particular during testing (I passed it by using number keys, but probably was a sign to remove)

          Thanks, I appreciate all the feedback, fixes coming in the next push

  • txr 1 hour ago
    Anyone who likes this should also take a look at: https://store.steampowered.com/app/1444480/Turing_Complete/ 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
    • battxbox 1 hour ago
      Love this game. Does anyone know if developers are still active?
  • unsnap_biceps 6 minutes ago
    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.
    • Jaso1024 2 minutes ago
      makes sense, idk if i want to remove times altogether (i personally found it fun + i want the game to be fun for all levels of familiarity), but ill add a modal to explicitly select difficulty level at the start of the racer game, i def agree w/ u overall
  • frmersdog 1 hour ago
    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.
    • Jaso1024 1 hour ago
      makes sense, adding to the next push (in the interim, u can also use the copy circuit button to ask gpt if ur correct or not), also, what level is this? (if u dont mind me asking)
      • sarvagyavaish 42 minutes ago
        Oh that's what the "copy circuit" button does. I have been trying to paste circuits from previous levels into subsequent ones and wondering what I was doing wrong
        • Jaso1024 25 minutes ago
          lol, mb; ill make that more clear (ill also give the ability to copy things cross level and intra-level)
  • yuppiepuppie 55 minutes ago
    Neat idea!

    Ive added this to the HN Arcade! https://hnarcade.com/games/games/mvidia

  • Anonyneko 2 hours ago
    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.
    • Jaso1024 2 hours ago
      Thanks for telling me this, I actually made an act 0 that went through the basics + physics of the pmos and nmos transistors, but i scrapped it b/c i couldn't get it to look like I wanted it to, will add it back
    • StableAlkyne 2 hours ago
      Glad I'm not the only one! I love these kinds of games; played the heck out of Turing Complete and Zachtronics' Engineer of the People... But I'd never heard of 3 state logic until today.

      Really threw me for a loop! I'm still trying to wrap my head around making level 3's NOT gate.

      This is such a cool idea, definitely the first 3-state circuit puzzler I've seen! Throw a cute story over it and I bet this would get some takers on Steam.

  • iandev 34 minutes ago
    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.

    For the PMOS, the output toggles between 1 and 0 (opposite the gate) as expected. However, for the NMOS, the output is always 0.

    I don't understand why GND pulls VDD down to 0 for the NMOS, but not the PMOS.

    • Jaso1024 13 minutes ago
      Oh, the drain should only be connected to the output, not drain aswell (irl this would kill one's chip, I'll add a feature to show short-circuiting). on pmos the source should be vdd, on nmos the source should be gnd (this doesn't apply for some later levels, but does for earlier ones).
  • xnzakg 24 minutes ago
    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"
    • Jaso1024 12 minutes ago
      Time to get on zetamac (all jokes aside, it should be optional, i'll also make racer games slower + adaptive soon (today))
  • john_strinlai 2 hours ago
    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

    otherwise, looks polished and fills in a nice niche!

    • II2II 2 hours ago
      There's the info boxes that it could be added to, that way it is always available at a mouse click.

      That said, I'm not sure how useful expanding most of the acronyms would be. Names like Negative/Positive Metal Oxide Semiconductor aren't exactly self-explanatory, Vdd isn't really an acronym, etc..

    • Jaso1024 2 hours ago
      I had an arc 0 where it went through some of these topics more in depth and explained them, deleted it b/c i couldn't get the UI to look right. I've pushed a bandaid that should fix this, but ill bring in arc 0 (it seems this is a popular request) after polishing it (ill also make it optional)
  • npinsker 2 hours ago
    Great game! For learning, might be nice to see some commentary or example (model) solutions after beating a level.
    • Jaso1024 2 hours ago
      Yeah, I've actually been planning to add this in, might have gemini look at your circuit config and give its opinion, alongside dynamic hints
  • Jaso1024 40 minutes ago
    Hi everyone, commenting to address feedback:

    - Made timed minigames optional (e.g. binary tables)

    - Added 7 (optional) intro levels to walk through pmos and nmos transistors

    - Fixed the bug in the capacitor levels

    - Changed editor bg to use dots instead of lines to fix wire confusion

    • sheiyei 32 minutes ago
      Layout appears unusable on my phone on Firefox Android (both portrait and landscape). Necessary elements seem to get hidden behind others. Not sure if I'm even supposed to be able to play it without kB&m though lol :)
      • Jaso1024 25 minutes ago
        Yeah, its not mobile-ready atm, ill push an update to make it mobile-friendly in the next day or so
  • himmelsee2018 53 minutes ago
    This is a brilliant way to visualize complex hardware architecture. As someone working on web-based image processing having a deeper mental model of how the underlying hardware handles these tasks is incredibly helpful. Truly a learn-by-doing masterpiece.
  • NooneAtAll3 53 minutes ago
    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?)
    • Jaso1024 19 minutes ago
      just pushed a fix
  • anderskaseorg 38 minutes ago
    The “next level” button takes you to the next level even if you haven’t solved that level’s prerequisites.
    • Jaso1024 30 minutes ago
      Thanks for telling me, just pushed a fix
  • gchadwick 1 hour ago
    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.
    • Jaso1024 48 minutes ago
      Yeah, a lot of people have said similar things, I'm going to make them all optional (coming in 30 min or so)
  • baobabKoodaa 1 hour ago
    Is this a sequel to "How to make a CPU"? https://www.youtube.com/watch?v=vuvckBQ1bME
    • Jaso1024 23 minutes ago
      lol, I hadn't seen that video before but its a good one. Na, this is the guide to comp arch that will (hopefully) end all instances of toil over documentation for any sort of processor when learning
  • joha4270 32 minutes ago
    So, is there anything about GPU's in here right now?

    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.

    • Jaso1024 18 minutes ago
      Not at the moment unfortunately, I've actually completed a good chunk of the GPU levels, but I think ppl will need to do act 2 and 3 for it to make sense
  • zapkyeskrill 1 hour ago
    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).
    • Jaso1024 1 hour ago
      Yeah, i'm planning to make it mobile compatible in the coming day(s), i didn't plan for this to be mobile originally, so it kind of sucks on phone
  • buildbot 2 hours ago
    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.
    • Jaso1024 2 hours ago
      Thx, way better (imo) than just reading slides or (god forbid) pure text describing comp arch
      • buildbot 2 hours ago
        100% agree - the way that you have the very subtle arrows on the transistor drains that show the actual current flow is really smart too. I struggled with visualizing the current flow in undergrad for an embarrassingly long time.
  • fleshers 1 hour ago
    This is awesome! The truth table lightning round took me by surprise, I am rustier than I thought...

    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.

    • Jaso1024 1 hour ago
      I see, thx, ill add a note in the game to make it more clear
    • Jaso1024 44 minutes ago
      truth tables round is optional now!
  • jmholla 1 hour ago
    The continue buttons in intro break for me all the time on Firefox. I can't actually finish most of them.
  • Ginop 2 hours ago
    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"...

    Well done and keep it up :)

  • NooneAtAll3 45 minutes ago
    truth table minigame is lmost unplayable in dark mode

    also it kept showing the same table to me like 4 times

    • Jaso1024 34 minutes ago
      I just pushed a fix for this, so it should be better now, its also optional now
  • NooneAtAll3 39 minutes ago
    level 1.10 I put 2 AND gates and only one of them works...
    • Jaso1024 35 minutes ago
      I want to fix this, could you elaborate a bit (would help even more if you pressed the copy circuit and pasted the result here)
      • NooneAtAll3 16 minutes ago
        Add 2 AND gates, 1 NOT gate

        G0 = D0 AND SEL

        G1 = NOT SEL

        G2 = D1 AND G1

        G0 -> Ans

        G2 -> Ans

  • arikrahman 3 hours ago
    Awesome project! Reminds me of Turing Complete on Steam.
    • Jaso1024 2 hours ago
      Yeah, that was the inspiration, felt that it didn't go in depth enough + didn't cover other processors, so I wanted to fill that hole + make it free
  • fragmede 59 minutes ago
    • Jaso1024 47 minutes ago
      Yeah, nand game was part of the inspiration, I felt that it was good but was a bit plain UI/UX wise and obfuscated / simplified some things that it shouldn't have
  • Falell 2 hours ago
    Fun. 2.2 loads a blank screen for me, all previous levels were fine and 2.3 loads. Windows, Firefox 149.

    Edit: Confirmed fixed.

    • Jaso1024 2 hours ago
      Fixed! If you go to the level and refresh (might need to hard refresh: Ctrl + Shift + R) it should load properly now
  • agrishin 2 hours ago
    Great project! I somehow missed whole cpu architecture topic, so gonna catch up on that now
    • Jaso1024 2 hours ago
      Yeah, fortunately I made cpu arch part of the game, so it'll serve great for that as well
  • aritzdf 1 hour ago
    PWAs have matured a lot — the gap with native apps is much smaller than people think, especially on Android where install prompts work reliably. One thing I appreciate about browser-based games specifically is that they sidestep the distribution problem entirely.
  • treelover 2 hours ago
    I like the concept! What tools did you use to build it?
    • Jaso1024 1 hour ago
      stack was mainly vite (react) + typescript pretty much (canvas 2d for the visuals)
  • schlecht_ 2 hours ago
    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.
    • Jaso1024 2 hours ago
      Sure, you should be able to rn though, is this after completing the level (wanna fix this bug)?
      • schlecht_ 2 hours ago
        Sure, but I can't seem to find the git?
        • Jaso1024 2 hours ago
          I haven't pushed to github (Will do this soon), but I believe that i've fixed the issue (also, by wanna fix this bug I meant I want to fix this bug, (but would def also appreciate help if ur interested, the mechanics of this game ended up being a bit more complex than I initially envisioned lol))
          • schlecht_ 2 hours ago
            No problem. I am currently on the third level I think and my laptop fan ramps up, so I closed the tab and it stopped. Also, how can I delete e.g. transistors again?
            • Jaso1024 2 hours ago
              I see, I'll try to reduce the load, i'm using canvas 2d so that could be causing it. you can delete by selecting then pressing the delete button (will also allow right click to delete in the next push, since i do this for wires)
    • Jaso1024 2 hours ago
      Fixed!
  • NooneAtAll3 57 minutes ago
    how do I remove/delete elements?
    • Jaso1024 55 minutes ago
      click and press delete, realizing this wasn't obvious, a fix to add a similar delete mechanism to how wires are deleted is coming
      • NooneAtAll3 38 minutes ago
        > press delete

        I don't see any button labeled that

        • Jaso1024 34 minutes ago
          oh, as in delete on the keyboard. it shoudl also work just to right click now (might need to refresh)
  • tithos 2 hours ago
    Cool concept, but it should be mobile friendly
    • Jaso1024 2 hours ago
      Good point (I didn't really consider this), might be a bit difficult tho tbh, but i'll push this soon
  • nottorp 3 hours ago
    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.
  • SilentM68 2 hours ago
    This is very cool!

    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.

  • PunchyHamster 32 minutes ago
    ...why capacitor has 3 pins ?
    • Jaso1024 22 minutes ago
      Yeah, I had added it to make it compatible w/ my simulation system, just changed how I was handling the levels altogether, if it still has 3 try doing a hard refresh (Ctrl + Shift + R on windows, cmd + shift + R on macos)
  • skyskys 2 hours ago
    wow looks really cool, although seems kinda useless at first look.
  • testaccount28 1 hour ago
    not playing past the truth tables bs
    • Jaso1024 45 minutes ago
      optional now!
    • Jaso1024 47 minutes ago
      lol (plz come back), will be optional in 30 min (lemme push)
  • bingbong06 3 hours ago
    [dead]
  • aritzdf 1 hour ago
    Launching on Product Hunt is useful for a burst of early feedback, but the retention from PH users is usually low — they're browsers, not committed users. Better to get 10 people who really need the thing than 500 upvotes.
    • Jaso1024 1 hour ago
      i didn't launch on product hunt