The old Nova instruction set, which lived on into the 16-bit and eventually 32-bit Eclipse instruction set, did have some curiosities: only four registers, and as I recall you couldn't do indirect byte addressing. The book does say that the architect on West's team had a much more VAX-like instruction set in mind for a project he didn't get to do.
That said, I was once at a customer's site that had an original "blue and white" MV/8000 (the MV series in general were brown-clad). If I remember correctly what the admin said, they boot up the new 32-bit OS, AOS/VS, for part of the day, and an older 16-bit OS, either RDOS or AOS, for the rest. I wish I remembered this more clearly.
And of course the VAX-style instruction set that West's architect envied fell out of style, didn't it?
That said, I was once at a customer's site that had an original "blue and white" MV/8000 (the MV series in general were brown-clad). If I remember correctly what the admin said, they boot up the new 32-bit OS, AOS/VS, for part of the day, and an older 16-bit OS, either RDOS or AOS, for the rest. I wish I remembered this more clearly.
And of course the VAX-style instruction set that West's architect envied fell out of style, didn't it?