I was hoping to get some insight into the roots of NT. At the time my understanding was that it resulted from the split between IBM and MSFT and that MSFT was a

I was hoping to get some insight into the roots of NT. At the time my understanding was that it resulted from the split between IBM and MSFT and that MSFT was already developing NT based on their derivative of OS/2. That was IIRC before Dave Cutler went to MSFT. Later on that (OS/2 -> NT) seems to have been scrubbed from history and NT is now derived from VMS. I'm curious where the truth lies. It was well documented at the time that early NT error messages occasionally identified themselves as OS/2. I'm over an hour in and not sure how close I'm getting to that. At about 1:09:00 Cutler states that they "developed NT on OS/2" but I think he meant their toolchain was hosted on OS/2 (and they couldn't wait to get off of it.)