that still amazes me to this day, learned to program on DEC stuffAdd to your list Digital Equipment Corporation.
And their one-time competitor Data General! Somewhere in my archives I have a copy of Tracy Kidder's very good book, "The Soul of a New Machine" (1980), about the development of the DG Eclipse! DG went from 1968 to 1999, while DEC, the former company of DG's founders lived from 1957 to 1998. That niche of mini-mainframes and distributed processing just got squeezed into nothingness.
that still amazes me to this day, learned to program on DEC stuff