Inkbox has created a 16-bit CPU that was built and runs inside Excel at a 3Hz clock rate and has 128KB of RAM, a 16-color 128×128 pixel display, and a custom assembly language that all runs in the popular spreadsheet. In fact, you can even try out the CPU with files the creator has made available via GitHub.

Microsoft Excel may be everyone’s favorite spreadsheet application, but Excel’s functions are actually quite flexible for a variety of purposes. If you were determined enough, you could use Excel’s conditional formatting functionality to create a functioning CPU within Excel. This bit of theoretical knowledge is also common knowledge, but no one really cares to demonstrate it.

That is, no one until January 27th, 2024. Inkbox decided to post a detailed 16-minute video (embedded below) on how they built a fully functioning CPU within the constraints of Microsoft Excel. Inkbox did this without applying any Visual Basic scripts or plugins, too— this is pure Excel work that could be duplicated on any PC you happen to have that runs Excel. And before anyone asks— no, it can’t play Doom.

Read more on Tom’s Hardware here and see Inkbox’s video below: