[ih] byte order, was Octal vs Hex, not Re: Dotted decimal notation

[Clem Cole]

On Tue, Dec 29, 2020 at 9:41 PM Brian E Carpenter via Internet-history <
internet-history at elists.isoc.org> wrote:

> > You'd probably have to find a PDP-11 designer...
>
> There was only one, really, Gordon Bell. I'm sure he didn't work alone
>
His two main grad students at CMU were Harold McFarland and Bill Strecker,
and much of the original work on the PDP-11 was done there. I was always
under the impression that McFarland was the higher bit, but I believe
Strecker designed a great deal of logic also.   IIRC it was Dave Cane (who
did the SMI and later the BI and of course lead the 750 team), once told me
that McFarland's most important contribution was the Unibus protocols (Dave
had joined the HW team to work on the memory system for the 11).

FWIW: Wulf and his students work on compilers and his paper
on instruction sets regularity were definitely in the team's mind and of
course the original BLISS-11 compiler was done at CMU during that same
time.  So some credit really needs to go to those folks too on the ISA.

As for byte swapping, I remember that Stecker once gave us a
lecture/seminar about the PDP-11 project in the early/mid-70s when I was a
student.  The question was tossed to him about why the 11 was byte-swapped
and he replied that it had saved 10ns in the carry look-ahead logic on what
would be the 11/20 processor design.  My memory is that it was Bill Wulf
who countered -  "but you cost us hours in programmer time."
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