Every Dell or HP laptop you've ever owned traces back to a $1 million trick a little Texas startup pulled on IBM in 1982. They copied IBM's computer without ever looking at IBM's code. This week Perplexity made the same trick free for anyone through Halloween. Here's how it worked. Back then, almost everything inside an IBM PC was stuff you could buy off the shelf. The one piece IBM actually owned was a tiny chunk of code called the BIOS, about 8 kilobytes, which tells the computer how to talk to its own keyboard, screen and disk drive. IBM even printed that code in the back of its manual. That sounds generous until you realize anybody who read it could get sued for copying it. So Compaq's lawyers split the engineers into two rooms. The first group read IBM's code and wrote down in plain English what every piece of it did. Rod Canion, one of the cofounders, said it felt like deciphering hieroglyphs. They passed those notes out through a window. The second group had never seen a single line of IBM code, and they wrote a brand new BIOS using only the notes. It took 15 senior programmers about nine months. It worked. The Compaq Portable sold 53,000 units and brought in $111 million its first year, and Compaq went on to become the youngest company ever to crack the Fortune 500. A company called Phoenix pulled off the same move in 1984 and sold its version to anyone who asked, and suddenly anybody could build an IBM-compatible PC. HP ended up buying Compaq in 2002. Fast forward to this April, when a developer who goes by morluto put a free tool called REA on GitHub. You point an AI coding agent at an app, no source code needed. The agent pokes around inside it, writes down evidence of how it works, and then builds its own working version from those notes. Read that again and you'll see Compaq's two rooms and the window, squeezed into one piece of software. Developers gave it more than 230,000 GitHub stars in six months. This week Perplexity built it into Computer as a skill and gave morluto credit by name. Their first demo was a Figma-style design tool with layers, auto-layout, sign-in, syncing across devices, and multiple people editing at the same time. Compaq needed a million dollars and a room full of senior engineers to do this one time, for one chip. Perplexity is covering up to 10,000 credits per person so anyone can try it on the app of their choice until October 31. The part I keep coming back to is what happened next in the 80s. Once anyone could build an IBM-compatible machine, the winners were whoever moved fastest. Compaq beat IBM to the first 386 PC in 1986, and by the 90s it was the biggest PC maker in the world. Software is walking into its own version of that moment. When an agent can study an app and rebuild it, what protects a product like Figma is the teams already working inside it and how quickly the next feature ships, and the code underneath gets cheaper to recreate every month. Compaq's three founders put in $1,000 each to start the company. Their whole edge came from a stack of notes slid through a window, and now anyone with a Perplexity account gets that window for free until Halloween.