28 Jun
2010
28 Jun
'10
10:27 a.m.
"Walter F.J. Mueller" <w.f.j.mueller at gsi.de> wrote:
> Johnny Billquist <bqt at softjar.se> wrote:
> > I wasn't aware that any prototypes ever were produced and came as
> > far as being functional. I thought it was just paper work that
> > had bee done.
>
> The 11/74 wasn't marketed, as pointed out in this thread, but a
> few systems were build by DEC. A picture of such 11/74 system
> was made available by Tim Shoppa, see
>
> http://www.trailing-edge.com/~shoppa/1174Xopen.jpg
>
> You'll nicely see the four CPUs.
Yes, I know of these systems. However, that is not an
11/74 on that
picture, but an 11/70mP. There is a difference...
As pointed out, the 11/70mP was marketed as an 11/74, but it's a
different CPU.
The easiest way to see that this is a picture of an
11/70mP is by
looking at the lower rotary switch, which only have four positions, and
not eight (which the 11/74 have). So no CIS on this machine.
The only 11/74 picture I've seen so far is the
silk screen panel picture
posted a few days ago. Unfortunately I've already forgotten the name
(I'm lousy with names, sorry) of the person who posted it, and who also
worked on the 11/74 CIS microcode.
The machine on that picture is probably CASTOR:: by
the way.
The people who work with/maintain CASTOR:: call it a 11/74, FWIW.
They never used the term "11/70mP" in front of me for sure. I would occasionally
elicit comments about multiprocessing on 73's or 93's but it always came back to
"our 11/74 does it THIS WAY" because that was the working example.
I'm not saying that "11/70mP" is wrong, indeed it's used in some of the
drawings and memos to describe what was commonly called the 11/74.
CIS was real important to some DECcies circa late 70's for some Cobol requirement but
coming from the real-time side none of us ever cared. We'd just run across machines
that had this unneeded option.
Tim.