@shanselman if your friends at IBM have source somewhere, it would be pretty cool if they could also open source IBM DOS/V 4.0J … it’s very different from other DOSes (and even the non-Japanese IBM DOS 4), and it would be a huge boon to preservation since there are not many copies of DOS/V 4.0 out there (and what is out there seems incomplete - I don’t think there’s a “last patch release” complete copy of DOS/V 4.0 that’s public; you have to mix and match).