When Excel Became a PC: The Incredible Creation of an Enthusiast

Some people look at Excel and think of calculations. Others see it as a playground for building 16-bit PCs.

We’ve already seen some crazy stuff in the world of digital DIY, like this computer built in Minecraft. Imagine: a 1 Hz processor, a graphics card with only 6 KB of video memory, and a screen limited to two colors.

But here we go to another level. One enthusiast actually built a 16-bit PC in Excel, and it works! A computer built in Excel is a small technological marvel with characteristics that defy belief.

3 Hz, 128 KB RAM…

We’re talking about a 16-bit machine running at a clock frequency of 3 Hz, a normal speed, but incredible when you imagine it’s running under Excel. It is equipped with 128 KB of RAM, which is quite surprising for this type of project. A 128 x 128 pixel screen can display up to 16 different colors. And all of this, built and run in a spreadsheet as physical as Microsoft Excel.

The cool trick of this project is the creation of Excel-ASM16, an assembly language designed specifically for this Excel PC. With 23 separate instructions, it handles basic functions such as variables or labels and binary files. This may be standard for assembly language, but it’s quite impressive when you consider that all of this runs on a 16-bit processor in Excel.

For those who really want to understand how it works, you should definitely watch the Inkbox video. They explain everything: how they used Excel features to run on a 16-bit CPU.