I’ve been making a little toy operating system for the 8086 in the last few days. Now that was a lot of fun!

I don’t plan on making that code public. This is purely a learning project for myself. I think going for real-mode 8086 + BIOS is a good idea as a first step. I am well aware that this isn’t going anywhere – but now I’ve gained some experience and learned a ton of stuff, so maybe 32 bit or even 64 bit mode might be doable in the future? We’ll see.

It provides a syscall interface, can launch processes, read/write files (in a very simple filesystem).

Here’s a video where I run it natively on my old Dell Inspiron 6400 laptop (and Warp 3 later in the video, because why not):

https://movq.de/v/893daaa548/los86-p133-warp3.mp4

(Sorry for the skewed video. It’s a glossy display and super hard to film this.)

It starts with the laptop’s boot menu and then boots into the kernel and launches a shell as PID 1. From there, I can launch other processes (anything I enter is a new process, except for the exit at the end) and they return the shell afterwards.

And a screenshot running in QEMU: