You are correct, but at the time UNIX was the only open OS available, which was the reason the company selected UNIX.
Major computer companies all had their own proprietary operating systems, which gave them exclusivity as to who could use it.
UNIX was available for almost nothing from AT&T, as Johnson and Ritchie re-wrote UNIX in C and gave it a real commercial start.
It had been bouncing around in labs and in colleges since the late 60s.
My first encounter with UNIX was in the late 70s when I was selling CRTs to AT&T into the labs in North Carolina and they were running a version of UNIX on both DEC and UNIVAC systems and making them communicate and share both programs and data.
I was a sales guy, not a techy, but even I knew the major implications of this beginning of open operating systems across the entire industry.
It was the beginning of the end for all major computer companies, Burroughs, NCR, UNIVAC, Honeywell, RCA and many that I can't remember became the walking dead.
“It was the beginning of the end for all major computer companies, Burroughs, NCR, UNIVAC, Honeywell, RCA and many that I can’t remember became the walking dead.”
I remember those guys dying out but it wasn’t because of UNIX, was it?