/AI3h ago

Builder Uses AI to Enable Quake 1 Multiplayer in Browser via Virtual Null Modem

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@levelsio@levelsio#840inAI

🔌Today I created a virtual web-based null modem so now you can finally play Quake 1 (from 1996) in multiplayer in the browser with other people online!

This week I was able to create a virtual printer that listens on the COM2 port to make a web-based printer work in Windows 3.11, like on you can actually print to, it was one of my ideas when I started http://pieter.com but it was always too difficult to make, I had no idea where to start, but this week AI was able to do it!

Today I woke up and thought "if we can listen to COM2 via JS, how about listen to COM1 from Quake 1?" then we could forward the COM1 data via Websockets and to another user to create a virtual null modem

(A null modem was a cable you'd use to connect two computers to each other directly in the 90s, if you couldn't afford buying a network card you'd use this to network, but you could only play with one other computer not multiple)

So I built it, it took about an hour and works! I wanted to get Quake 1 in DOS to work with multiplayer for 2 years but I could never get it to work, but now it did it

This project is a good benchmark of how capable AI is becoming, figuring stuff out that humans would take months within an hour

You can try it here, I don't know how it will match lots of people but let's see, you have to exit to DOS first (ALT-F4 or FN-Option-F4 on Mac), then type CD games, then CD quake, then quake, then ESC, then Multiplayer, then either Create New Game or Join Game, and use Direct Connect, keep settings same and you're in!

https://pieter.com/assets/dosbox/nullmodem-test/index.html

@levelsio@levelsio

🖨️ Next in the printing saga: I installed Print Shop Deluxe 2.0 from 1994

It lets you print these giant banners, I vaguely remember doing this too

And it works with our web-based matrix printer!

You can try it on http://pieter.com, make sure you select the vertical ones, as I didn't get the horizontal printing to work (yet)

5:28 AM · Jun 10, 2026 · 30.1K Views
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Many users praised the builder's use of AI to create a browser-based null modem for Quake multiplayer because it revives old games in a magical way and evokes 90s nostalgia.

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@levelsio@levelsio

Here's how a null modem looks like :DD

@levelsio@levelsio

🔌Today I created a virtual web-based null modem so now you can finally play Quake 1 (from 1996) in multiplayer in the browser with other people online!

This week I was able to create a virtual printer that listens on the COM2 port to make a web-based printer work in Windows 3.11, like on you can actually print to, it was one of my ideas when I started http://pieter.com but it was always too difficult to make, I had no idea where to start, but this week AI was able to do it!

Today I woke up and thought "if we can listen to COM2 via JS, how about listen to COM1 from Quake 1?" then we could forward the COM1 data via Websockets and to another user to create a virtual null modem

(A null modem was a cable you'd use to connect two computers to each other directly in the 90s, if you couldn't afford buying a network card you'd use this to network, but you could only play with one other computer not multiple)

So I built it, it took about an hour and works! I wanted to get Quake 1 in DOS to work with multiplayer for 2 years but I could never get it to work, but now it did it

This project is a good benchmark of how capable AI is becoming, figuring stuff out that humans would take months within an hour

You can try it here, I don't know how it will match lots of people but let's see, you have to exit to DOS first (ALT-F4 or FN-Option-F4 on Mac), then type CD games, then CD quake, then quake, then ESC, then Multiplayer, then either Create New Game or Join Game, and use Direct Connect, keep settings same and you're in!

https://pieter.com/assets/dosbox/nullmodem-test/index.html

3hViews 6.4KLikes 27Bookmarks 1
BOOKMARKS4
@levelsio@levelsio

How it works

@levelsio@levelsio

🔌Today I created a virtual web-based null modem so now you can finally play Quake 1 (from 1996) in multiplayer in the browser with other people online!

This week I was able to create a virtual printer that listens on the COM2 port to make a web-based printer work in Windows 3.11, like on you can actually print to, it was one of my ideas when I started http://pieter.com but it was always too difficult to make, I had no idea where to start, but this week AI was able to do it!

Today I woke up and thought "if we can listen to COM2 via JS, how about listen to COM1 from Quake 1?" then we could forward the COM1 data via Websockets and to another user to create a virtual null modem

(A null modem was a cable you'd use to connect two computers to each other directly in the 90s, if you couldn't afford buying a network card you'd use this to network, but you could only play with one other computer not multiple)

So I built it, it took about an hour and works! I wanted to get Quake 1 in DOS to work with multiplayer for 2 years but I could never get it to work, but now it did it

This project is a good benchmark of how capable AI is becoming, figuring stuff out that humans would take months within an hour

You can try it here, I don't know how it will match lots of people but let's see, you have to exit to DOS first (ALT-F4 or FN-Option-F4 on Mac), then type CD games, then CD quake, then quake, then ESC, then Multiplayer, then either Create New Game or Join Game, and use Direct Connect, keep settings same and you're in!

https://pieter.com/assets/dosbox/nullmodem-test/index.html

3hViews 4KLikes 24Bookmarks 4
Enes Poyraz@ens_pyrz

@levelsio I like those kinds of experiments. I am currently porting Contra (NES) from ASM to C and then from C to WebAssembly. I can't code in C. I never did a Project in WebAssembly. Claude did all of this. It works:

3hViews 35
Tasuku Miura@surfer_tas

@levelsio what about downloading a tiny image over a 56k modem.

the wait was always worth it.

2hViews 21Likes 1
Maliik Bryan@Don_adijah

@levelsio Doing the transport as a virtual null modem instead of just opening a websocket is full commitment to the bit. I built browser multiplayer on an authoritative Colyseus server and honestly the 1996 stack has fewer moving parts.

2hViews 55
jimSBr@jimsbr

@levelsio Okay, this is epic

3hViews 40
Lunari@0x_lun

@levelsio emulating a null modem over the web so two browser tabs can play quake together is genuinely unhinged and i respect it

3hViews 35
panaizzz@panaizzz

@levelsio Lool i need to try this with my brothers

3hViews 34
Humbulani@HumbulaniNd

@levelsio This approach definitely works for you very well. You already have solid distribution inplace. A nobody may build all these and still have 0 users.

2hViews 30
Evgeny Sorokin@_EvgenySorokin

@levelsio And how am I supposed to work after seeing this? 🫠 as cool as it is crazy

3hViews 30
Ricardo@ricardovg

@levelsio The null modem didn't work for me. CL_Connect : Connect failed

I typed HELP,got into single player, and eventually it quit with an error saying a modified game requires a registered version.

(Using Brave browser)

1hViews 23
Bruno Serrate@SerrateDevs

@levelsio I rlly like that you can just port old games to web and just work lol The other day I was googling to play Star Fox 64 and just pop up a web version of it

3hViews 23
Jean@JohnStrongHodl

@levelsio memories revived, but printer one was even more something else :D

3hViews 6Likes 1
Thiago Cardoso@tncardoso

@levelsio Team Fortress almost confirmed!

1hViews 20

@levelsio the “what if i just tried this?” moments are undefeated

3hViews 18
Nathan Tulu@nathan_tulu

@levelsio QQ is this legal? I have a 2000's game I would like to create private server too.

50mViews 12
Dave Overton@daveove

@levelsio Ok, I’m having so many flashbacks to 90’s PC era now!

2hViews 10
Vlad Vereskoun@Vlad_Vereskoun

@levelsio SO nostalgic! We plugged our 2 pcs together with my friend and played Warcraft 2. I had to carry my system block and my heavy monitor to his place but it was worth it as real modem connection for multiplayer was a nightmare back then

28mViews 9
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