I built a web-based virtual null modem to play Quake I in MS-DOS in multiplayer online β @levelsio (Pieter Levels)
← all postsI built a web-based virtual null modem to play Quake I in MS-DOS in multiplayer online<br>10 June, 2026 Β· 2,282 views Β· 15 likes Β· 0 reposts<br>AIGamesTechStuff I madepieter.com<br>πToday I created a virtual web-based null modem so now you can finally play Quake I (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 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 I?" 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 I 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!
pieter.com/assets/dosbox/nullmodem-test/index.html
How it works
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