Thanks for the kind words Sam. I don't have the capacity to share the process in a fun and interesting way, but I wrote this in C on a modern desktop PC, used http://gamedev.allusion.net/softprj/kos/ as an interface to the Dreamcast hardware. There's forums where people still discuss DC dev, and the 'Simulant' discord server is very active with dreamcast developers.
Also: amazing glasses in your pic