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I built a web-based dot matrix printer that prints from Windows 3.11

7 June, 2026 · 85,736 views · 163 likes · 10 reposts

🖨️ It took over a year and lots of help from Claude Code but I have now been able to create a real dot matrix printer on the web that prints from Windows 3.11 in your browser:

Here's the test page: pieter.com/assets/dosbox/serial-test/

I couldn't get the LPT1 port to work but COM2 did work (the dial up model already uses COM1), the JS receives the COM2 serial data (just raw print data) and then prints it

Next is to make the dot matrix printer better looking (kinda 3d like on pieter dot com) and have the paper also flowing in 3d out of the printer and integrate it on the pieter.com page

My idea was that it might work because we also capture the COM1 data (from the dial up modem) and send it to a Websocket as a dial up connection, so we should be able to capture the COM2 traffic too but I didn't know how, but now I do

IT WORKS!! 😊

Oh to use it, one thing, you have to go to control panel, printers, set as default printer, and close! Then go to Notepad and you can print

Rough draft but the print will come from this printer here or well that's the goal

Why??? I don't know I just have to make it

🖨️ Little progress: I generated a dot matrix printer with GPT Image 2 and then some Photopea'ing to make the paper go through

And I got COM1 to work for dial up internet to pieter.net (my ISP) while COM2 still works for the printer (that was a challenge)

Which means I can now print anything from the internet, like Hacker News!

Some todo fixes:

You can try it the current WIP here: pieter.com/assets/dosbox/serial-test/

🖨️🖼️ Big progress: it can now print images too

I had to install a different printer driver, Claude Code recommended Epson FX-86e which supported images

Then I printed an image, it helped me dump a .bin from the printer raw data output, then it decoded the .bin and figured out how to draw images on a canvas (in the printer) from that data

So crazy I'd have no clue how to do this without AI ever!

Here's the WIP pieter.com/assets/dosbox/serial-test/

Next is integrating it to the frontpage

Ok deployed it on pieter.com and integrated into the full site

Only thing is perspective is a bit off, so I'll try edit the printer with GPT Image 2 to get a slightly left view of it so it fits better

But it works, fucking crazyyyyy

By far my most autistic project ever 🤓🤓🤓

pieter.com

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