Wow. Remember that this on a machine that isn't actually designed to play digitized sound at all! (Though ways to hack the chip to do just that have certainly existed for a while, as mentioned in the article.)
There's an elegant simplicity in these old pieces of hardware, it's relatively easy to study them exhaustively and if you're clever enough you might find a new way to fit the pieces of the puzzle to do something nobody had though possible before. If you want to hack a modern PC you'll probably first have to spend a few years reverse-engineering the various parts to figure out how they work exactly and what you can do with them. Even getting a basic understanding of the low level details of a modern GPU is quite a massive undertaking.