@bytex64 @nina_kali_nina There was an effort in the early 2000s to produce a free BTRON implementation independent of Panasonic and PMC, known at various points as B-free, BTRON386, and EOTA, although this only ever produced what amounts to a Unix with an ITRON microkernel and a weird Forth-like shell; they never got around to actually implementing the BTRON subsystem for it (this will of course be in my OS museum VM as well)