I don't see the point of this project. It essentially turns the IBM PC into an embedded system where the only program you can run is the one you burn into the

I don't see the point of this project. It essentially turns the IBM PC into an embedded system where the only program you can run is the one you burn into the ROM. There is little, if any, advantage to avoiding the use of interrupts. While using unused MDA memory as general purpose memory is cute, it doesn't offer any advantage since you can't reasonably disable DRAM refreshes on the PC (and still get any usable work done), so you might as well use RAM you know will be present on all PCs. The entire point of the BIOS is so that programs could use BIOS calls and work on any PC or clone without needing to worry about the underlying hardware. Such programs still work today (if you can find a way to boot/run them) which is fairly astonishing 40 years later. The project states "The purpose of this project is to explore controlling the IBM PC hardware in non-standard ways." Okay, well, that's cute, but unless there's an advantage, why bother. If you're going to do that, you might as well make a demoscene demo...