Snowdrop OS: a homebrew operating system from scratch, in x86 assembly language

Snowdrop OS was born of my childhood curiosity around what happens when a PC is turned on, the mysteries of bootable disks, and the hidden aspects of operating systems. It is a 16-bit real mode operating system for the IBM PC architecture. I designed and developed this homebrew OS from scratch, using only x86 assembly language.

↫ Snowdrop OS’ website

I have created and included a number of utilities, including a file manager, text editor, graphical applications, BASIC interpreter, x86 assembler and debugger. I also ported one of my DOS games to it. After all, what kind of an operating system doesn’t have games?

It seems like every talented programmer will, at some point, think to themselves: I should write my own operating system. Most of these efforts strand pretty quickly – and that’s fine! – but Sebastian Mihai’s effort did not, and it has grown into a very capable operating system, especially given the constraints stemming from the chosen architecture – 16bit realmode x86 – and programming language – x86 assembly. Snowdrop OS is an incredibly impressive labour of love, and comes with a unique extra I haven’t seen before: a daily development log covering over 600 days of development.

No, this won’t take over the world, but I love that is exists. More of this, please.

2 Comments

  1. 2025-01-22 8:34 pm
  2. 2025-01-22 9:16 pm

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