MIOS: IBM 5150 BIOS replacement project

This webpage describes the MIOS Project. MIOS is a chip-for-chip replacement of the BIOS (Basic Input Output System) on the IBM 5150 Personal Computer. On the IBM PC the BIOS is contained in a ROM IC Chip located on the motherboard at socket location U33. The IC is socketed and can be replaced with a custom ROM containing custom code.

The purpose of this project is to explore controlling the IBM PC hardware in non-standard ways. The purpose is not to replace the BIOS with another BIOS that does exactly the same thing! We are going to describe how MIOS works by describing the path we took for development.

Amazingly cool project. I’m not entirely sure for how long it’s been around, but that doesn’t make it any less awesome.