So Microsoft just dropped what they're calling the earliest DOS source code ever discovered, and naturally, my first instinct was to try building it. If you had the same idea and hit a wall of cryptic assembler errors, you're not alone.

Here's how I got it compiling and running on a modern machine, and what I learned about 8086 assembly along the way.

The Problem: Ancient Assembly Meets Modern Toolchains

The DOS source code is written in 8086 assembly — we're talking circa early 1980s, before most of us were born (or at least before we were writing code). You can't just clone the repo and run make .…