[Info-vax] Dave Cutler, Prism, DEC, Microsoft, etc.

[Rich Alderson]

koehler at eisner.nospam.encompasserve.org (Bob Koehler) writes:

> In article <mddljhj4ohn.fsf at panix5.panix.com>, Rich Alderson
> <news at alderson.users.panix.com> writes:

>> There's no such thing as "the PDP"!  DEC built 4.5 different architectures
>> which it labeled PDP-<number>, you know.

>    I think you underestimate the number of architectures known as PDP,
>    although a lot of them vary more by word size that top level
>    concepts.

18 bit: PDP-1, and PDP-4/-7/-9/-15.  The latter were upwards code compatible,
        but not the PDP-1.  That's 1.5 in my count. 

12 bit: PDP-5, PDP-8, -8s, -8i/l, -8e/f/m, -8A.  That's another 1, for a total
        of 2.5.

36 bit: PDP-6, PDP-10 = KA10, KI10, KL10, KS10.  That's another 1, for a total
        of 3.5.

16 bit: PDP-11 in all its forms and variations.  That's another 1, for a total
        4.5.

You're probably talking about the PDP-14 and PDP-16, and you're right, I didn't
count them as separate computer architectures.  I still don't.  If instead you
are counting the minimal variations among members of those families as separate
architectures, then we have a fundamental disagreement on what that word means
in this context, and have nothing substantial to discuss.

So yeah, 4.5 computer architectures called PDP-<x>.

-- 
Rich Alderson                  "You get what anybody gets. You get a lifetime."
news at alderson.users.panix.com                           --Death, of the Endless