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Retro CRT terminal screen in CSS + JS

Edwin on February 21, 2020

As a fun project, I decided to create a terminal interface that has the look and feel of an old CRT monitor. The terminal is responsive, but it m...

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maveric • Nov 7 '20

Edwin,

I love this. By far the most in-depth, well written fallout game (as well as the terminal, but I found it looking for the fallout game) I've seen yet. The fact that it's in such an amazing package of the terminal with scanlines, typing, other command framework. It's great.

I'd like to use this for our airsoft events that we host (you read that right) and would like to know how to properly attribute you. I also have a question about why / how to fix - in the fallout game, when the typer is updating the lives (updateLives()) and you move the cursor it cancels the typer and can sometimes mess up the ending of the game (assuming waiting for a promise that gets wonkey?)

If you're willing, let me know your thoughts on the typer, but please let me know how to best give you credit to our players.

Edwin • Nov 7 '20

Hey, thanks man! I'm really happy to hear that other people use my code for all kinds of stuff! I have not really thought about how to give credit, maybe just link to my dev.to profile for now. I was working on a portfolio site, this might be the motivation to actually finish it. :)

About the updateLives function, I assume you want to wait for the updateLives function to finish before doing the next thing. I see that this function does not return anything, that may cause the issue?

async function updateLives() {
    let span = document.querySelector(".lives");

    let blocks = Array(lives)
        .fill(0)
        .map(() => "■ ")
        .join("");

        // Added return here
    return await type("Text", { clearContainer: true }, span);
  }

Then you can wait for the function to finish by using async/await:

async function doStuff() {

  //...
  await updateLIves();
  // should wait for updateLives to finish

maveric • Jun 17 '21

I'm not sure if you are still reading comments on this article but we had our airsoft event last month and these were a HIT. I loaded it up on some rPi's and battery packs with wifi that redirected all traffic to the pi.

I built a local backend API that took in the "command" and tested it against our list and sent back either brogue or fallout to run based on our new command names. Then hooked into the win/losses and sent that back to the api so we could have dynamic win/loss messages based on the game that was played. It added something completely new to the airsoft world and we will absolutely be bringing it back in future games.

Edwin • Jun 18 '21

That's so cool! I picture this as a "retro arcade" that you use during the downtime of the airsoft event? Thanks for the update!

maveric • Jun 18 '21

Nope. :P We've got the pi's people connect with with their phone and a few toughbooks they've got to be in front of. You've got to have people pull security (to keep enemies away) or play the game under fire in order to get the information out of it to complete your mission and keep things progressing. The "hacking terminal" is very much a part of the live fire scenario game.

Edwin • Jun 18 '21

That is freakin' genius! Sort of "hacking" mini-games during the event, that's so creative! Reminds me of this "scavenger hunt" game that we used to play on my university campus.

I'm currently playing a game called "Control" which also has some terminal based mini-games, might add it to this project. (no promises tho)

maveric • Nov 7 '20 • Edited

I've made that change, and the execution does not seem to change. I have a "console.log" immediately following the call to updateLives that in fact will not show until it completes. But if I move the mouse, the

wordSpan.addEventListener("mouseenter", handleWordHover);

gets called (as it's on all elements) and seems to interrupt the promise. If I move the mouse, I never get that console.log statement for that call. If that game ends with that interrupted, it won't show the game end typer properly.

I have not been able to find any resources on this type of interaction - an event listener popping off during an await that messes it up - and this whole async/await was not a paradigm when I was coding last. Trying to catch up.

Your help/suggestions would be greatly appreciated but I know this was just a side/learning project, not something you intended to support and won't be offended if you chose not to.

Edwin • Nov 7 '20

If I could look at the code somehow I can help debugging. Can you put it online somewhere like a codesandbox?

maveric • Nov 7 '20 • Edited

The sandbox is at:
codesandbox.io/s/hungry-booth-wyl1...
It really is just your code that I've made some minor bug fixes and personal debug/figure out code to. The same thing happens on the sandbox from this write up as well if it's easier to look at code I haven't put any hack-it-to-figure-it-out code into.

Edwin • Nov 8 '20 • Edited

Oh, it was easier than I thought.

I defined the interval variable at the top of the io.js module. Everytime you call type() it will overwrite the interval. I use setInterval to process the queue of characters one by one. So if type() is called while another is still running, only the last one will finish.

Moving the interval variable inside the type() function ensures every promise will execute asynchronously like you expect. Not sure why I wrote it like this in the first place, probably because I thought I would only need 1 typer at the same time, lol.

maveric • Nov 8 '20

That's fantastic. I'm very glad it was an easy find for you and greatly appreciate you looking into it for me. Works like a charm. That would have taken me ages to find, as I was going down the "how's the promise getting messed up" path.

I've got a lot to learn, but you've got great code for me to follow, so thanks again.

Chafalleiro • Aug 5 '22

Hello I borrowed your code, also added some SVG effect to do a barrel distortion of the screen that you can find interesting. Credited in the credits menu, I hope the crediting is correct.

chafalleiro.github.io/retromator/v...

Edwin • Aug 5 '22

This looks perfect! 🤩

Chafalleiro • Aug 6 '22

Thank you very much :) Certainly you post helped me a lot.

fhgaha • Feb 21 '23 • Edited

im trying to repeat. almost done but cant find what "sphere_wide_1.png" look like

H-Baguette • Jan 2 '21

Hey! I'm trying to use this code to make a small terminal for a game, but... for whatever reason, it's saying the :after elements are invalid names, and thus none of it shows up. I'm also having an issue of my scanlines appearing over my border image.

Edwin • Jan 2 '21

Can you show me the code somehow? Codesandbox or github? I'm not sure what you mean.

H-Baguette • Jan 3 '21

I managed to fix most of those issues, plus a few more I was having after adapting it for my own purposes, but I'm still having the issue with the scanlines appearing over the corners of the border image. The code's probably gonna look confusing and spaghettified to all hell, but I can add you to the Github repo, if you want to take a look.

Sungbin Lee • Jun 15 '23

Hey Edwin, Just wanted to say a big thank you for your amazing article. Thanks for sharing your knowledge. It's been a huge inspiration for my project! github.com/sungbinlee/TicTacToeWit...

Edwin • Jun 15 '23

Hello Sungbin Lee, that's a cool project, glad I could be of help! :D

RIZ • Jul 21 '23

Hey Edwin,

I'd like to say i love the way you designed your terminal and I'm glad it's being used to help other people. I was just wondering if it's possible to convert the terminal into a text editor tool instead given that I cannot freely text as i receive "unknown command" error whenever i type.

I'm not tech saavy at all so I'm unsure how to utilise Sandbox or any of the other tools used to code. Any feedback would be greatly appreciated

Edwin • Jul 24 '23

Hey RIZ, I made a new command text-editor command, it saves what you typed in your browser.

tlijm.csb.app/?command=text-editor

RIZ • Jul 27 '23

yeah, i've been playing around with it and it works perfectly. i appreciate the support edwin and will continue to follow and support your work.
have a nice one mate :)

Doug Davison • Jul 16 '23

It would be cool to use this to build various screens for use during an RPG session. I could see a need for building a custom intro screen for each terminal's welcome screen and login, and then menu items that do various things or open log journal records.