On Wed, 30 May 2001, Thor Lancelot Simon wrote:

> I'm pretty sure the 784 existed, though not for long.  I recall finding
> the part number for the "11/784" badge in one of the big thick white
> books when I worked at DEC many years ago.  I've also spoken to people
> who said that they'd run into 3- and 4- processor systems in the field
> that were running VMS in asymmetric multiprocessing mode using the MA780,
> and one person in particular I met at a long-ago conference who proudly
> said that *his* site had one of the few machines with an actual DEC 11/784
> badge.

Would be interesting if anyone *really* could confirm this. :-)

>  As I said, I think that was Ontario Hydro.  Also, I think the
> multiprocessor PDP-11 they had was an 11/70M (a Massbus PDP-11); the 11/74
> is just a Qbus J11 machine with a Unibus behind a bridge; it was general
> wisdom in the late -11 era that swapping a 70 for an 84 (the 74 is just a
> slower 84), as DEC liked to suggest, was often not a good idea because of
> the lost I/O bandwidth.  Or are you talking about a multiprocessor J11
> machine?  That'd be interesting.

Nope. The 11/74 is a four cpu 11/70 machine, with shared memory, buses,
and some interprocess device. There is no such thing as an 11/70M. The CPU
in the 11/70 is normally a KB-11C. The multiprocessor version is the
KB-11Cm, and there were plans for a KB-11E, which would be multiprocessor,
and also have CIS.

The J-11 looks like it have all the bits required to go multiprocessor,
but DEC never did anything with this as far as I know.
The 11/74 on the other hand I *do* know about...

The story about Ontario Hydro goes something like this:

A DECUS meeting, where DEC reps. are talking to customers, trying to
convince them to upgrade their machines. One of the big arguments is the
savings in power consuption. The Ontario guy says: "Maybe you didn't hear
where I come from. I'm from Ontario Hydro"...

Ontario Hydro also reputedly was one of the test sites for the 11/74, and
was said to have just invented the word "no" when the field test came to
an end, and DEC requested that the machines should be returned.

I've tried to dig out the facts behind this, and people at DEC claims that
this isn't true. All field test 11/74s were in fact returned at the end of
the test period. None remained out in the field.

	Johnny

Johnny Billquist                  || "I'm on a bus
                                  ||  on a psychedelic trip
email: bqt@update.uu.se           ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol