North Star Horizon

From: Bill/Carolyn Pechter <pechter_at_shell.monmouth.com>
Date: Sun May 17 03:53:16 1998

> <> PDP11/74,
> <
> <Did DEC ever market these, or were they (all four of them, or
> <whatever) just a last ditch effort to save the PDP-11/70 line?
>
> No, never marketed. Accoring to some they were built with existing
> parts. It was not persued because it would eclipse the vax and the
> 11/70 design was not emi/rfi complient and would be very difficult to
> make it so. At the time the 16 bit mini market was seen to be getting
> smaller in favor of the 32bit superminis.

Actually they were slightly different. (Different front panel,
cache memory and memory control, different backplane.) They were
pretty much the same old 11/70 cpu with CIS on em. KB11-AD=11/45,11/50
11/55 CPU. KB11-B,C=11/70 CPU, KB11-CM=11/74 CPU. I seem to remember
references to the KB11-E somewhere.

When AT&T needed the last available 11/70's for use in their
operations (SCAMOS, COSMOS etc) they bought every last one DEC could
supply. DEC was buying them up from customers on Vax trade-ins, refurbing
them and selling them to "the Telephone Company" so they could
avoid having to get them redesigned and rereleased with new FCC
specs.

DEC split up the remaining internal 11/74's and shipped them to regional
offices to use them as internal use only 11/70 replacements (ours was
the regional sales order processing RSTS/E 7.2 system. We just hoped
it would never die, because we had no spares for the beast beyond the
straight 11/70 spares kit.

>
> Allison
>

Does anyone know what the "Unicorn" system was. I hear it was an even
later 11 prototype using the what would later become the VAX 11/780
SBI as it's bus. My friend saw the theory of ops on the memory while
building the earliest 11/780's -- but no one has any references to a
Unicorn being created.

There was also the design of the Bluefish 11/68 follow up to the 11/60
and 11/74 (but that was never built).


Bill

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Received on Sun May 17 1998 - 03:53:16 BST