On Mon, Jan 20, 2020 at 1:04 PM Larry McVoy <lm@mcvoy.com> wrote:
I know those Nat Semi chips very well, or did at the time.  I so wanted to
love those chips, the instruction set felt like whoever did the PDP-11
did the 320xx chips.
It was clear, the NS folks, like the Moto folk, knew the PDP-11 and VAX.   It was a nice architecture and should been a win but...

 
But they couldn't produce chips without bugs and that killed them. 
I really think it was they were the third man and too late.   Between Apple on the Mac and Apollo, Masscomp and eventually Sun, the 68000 and later 68010 had volume.   8086 family had volume with the PC.

As Jon can tell you, Tektronix decided the use the NS chip and tossed a working 68000/68010 design (Magnolia - which would later ship at 4400) for a completely new workstation.  But it meant starting from scratch.   Big mistake... 

If they had just shipped Magnolia at the beginning, I'm not sure either Masscomp or Sun would have been birthed.   Apollo and Triple-Drip were already there, but thy would have had the first UNIX workstation on the market, with a super graphics system.  Sigh....

 
It's a crying shame, I liked the instruction set
WAY better than the VAX.  The VAX seemed really messing compared to
the PDP-11, the 320xx chips seemed clean.  Might be rose colored
glasses but that's my memory.
I would not say way better, but much cleaner.  To DEC's credit, the idea of the VAX was to take the PDP-11 forward and keep things running.   Funny, DG did that better in the end, but that was the idea at least.   NS was trying to make the VAX without the rough edges, mistakes DEC had made.  Prof. Yale Patt consulted on both Instructions sets BTW, which may be why they look so similar.