That is why I said "based". "Based" means that you did not have to requalify a lot of the parts, that you could use a lot of the same Bill of Materials....it does not mean you use exactly the same PCB. In the case of the VAXstation/DECstation 3100 that meant we used the same serial io chips and did not provide the hardware flow control.
Yes! It's coming back to me, the 3100s were horrible for serial,
though I think they had fixed it for the 5000 series systems, since
the DECstation 5000 and the DECserver 5100 were identical, except the
DECStation had a graphics card and cost 10-20% _less_ than the
DECstation 5000. So we bought DECStations and used them as servers.
The server groups were different engineers, and the 5000s were designed after the DECstation 3100/2100 series.
Actually we MIGHT have caught the issue with the serial port for the DECstation 3100/2100 because I brought up the issue in a hardware meeting and was assured that it had been fixed because (and I can still hear this person's voice in my head) the DECstation was a REAL UNIX MACHINE. I should have found that person later and beaten him to death.
Actually, Cutler was already in trouble with management because
of the Prism project. Prism was the first try at building a RISC
machine (this was in the 1985-1986 time frame) and it was managed
by Dave Cutler. Unfortunately, Dave was not a good
administrator. He was doing a very bad job of managing the
project and doing a very bad job of keeping management up to date
on what was going on. Finally, management cancelled Prism and
that is when they decided to go with the MIPS architecture.
That is not what I experienced. I will not comment on Dave's skills as an administrator or manager of the project. I do know that he had the very ambitious project of doing the next-generation architecture and the next generation operating system. He wanted a micro-kernel based system with "personalities", one personality being VMS and the other personality being Unix. One issue he had was when there was a clash between personalities he would always favor VMS and therefore the Unix personality would not be "perfect". I felt this was a mistake, since Unix people did not tolerate things that did not smell like Unix. VMS people could have been led over to a new environment over time since DEC controlled the path with VMS.
The reason I know this is that I personally interviewed with David Cutler for the position of Unix Product Manager for his new operating system. The interview was going fine until I tried to explain to Dave why his strategy was wrong and he had to make the Unix side really compatible. Then things got ugly, as David really did not like to be told he was wrong.
Ken did have the bad habit of cutting off Dave's development money, then giving it back to him again. I seem to remember that Dave was still going full steam ahead while the PMAX was being developed, which is one reason why he was caught so flat-footed when PMAX was announced. It was kept REALLY SECRET. It probably did not help that Ken reportedly asked David in a gleeful tone if the new chip would be as fast as the PMAX....
"Will it be THIS FAST, Dave?" was the reported question.
It is also my belief that the Alpha chip came directly from Dave's work on the PRISM, and that Windows NT came directly from David's work on the microkernel with personalities. DEC never "decided to go with MIPS" except as a stop-gap measure for Unix. If DEC had "decided to go with MIPS" they would have ported VMS to it, and since that never happened, it was obvious that DEC had not embraced MIPS.
md