I never got beyond writing a FAT12 boot sector (it could load and pass control to a 16-bit binary in the root directory, with any amount of fragmentation) and a CPUID app that can detect anything from 808x up to the first 64-bit CPUs. Then my poor health got in the way. I hope to resume coding this year - health hasn't improved, but has stabilised. I did plan to write a simple 32-bit OS that can detect and initialise a wide range of hardware, and I hope to at least get that underway. Might write a DOS based IDE in nasm, and convert my windowing code to nasm as well (in MSVC 1.52, I wrote a windowing system for DOS that could load 1024 child windows and switch between them, I forget how much memory it needed, but it could work on a 386 at a usable speed).