4 Oct
2009
4 Oct
'09
8:14 p.m.
I worked on one or two in the field back in the '70's, but don't remember
very much about system configurations. I don't remmember anything about the
main box.
I have a VT14 terminal, 14/30's, 14/35's, ICR11, ICR8, ICS11, ICS8, some in
quantity. I also have a large quantity of H1600's, H1500's, H1550's,
H1650's
and their corresponding distributuion panels. I'm taking these numbers from
memory so the numbers might be a little off and this list is by no means
complete. The documentation for most items is here and I offered it to Al
to scan a few years ago, but he has probably forgoten about it now.
If anyone has working knowledge of this equipment, please feel free to
contact me.
On Fri, Oct 2, 2009 at 5:04 PM, Charles H Dickman <chd_1 at nktelco.net> wrote:
I have never seen one alive, but I have the remains of
one: logic unit
boards, miscellaneous generic flip-chips, some I/O boards, etc.
Unfortunately, no backplane. This was the original PDP-14 (Straight-14?). It
was to have a core-rope ROM in the final installation vs. core. I think
there were later versions that had writable program storage.
Shoppa, Tim wrote:
The PDP-14 was not a conventional computer... it
was what we call today a
PLC
(programmable logic controller). Very adaptable to ladder logic and a bit
more.
Very primitive, but the right thing for discrete logic control.
I have some notes about it here: http://www.chdickman.com/pdp14/
I think Motorola had a 16pin dip logic unit that did basically the same
thing.
DEC was pretty swift in how they allowed the
PDP-14 to be configured via a
real computer (a -11 or -8). It wasn't the GUI of PLC configuration today or
even of the 80's, but it was a good start.
The parts I have came from a system that was to have run a stamping press.
In this case, the PDP-14 was basically a discrete I/O adapter for a PDP-8/e.
The overall model of PLC configured or monitored
by a computer still holds
true today, I think that DEC could have really taken this idea and run with
it but the overlap between industrial control and computers even today is
less than thorough. The computer geeks don't understand the industrial
control and process engineers for the most part (thus the common misuse of
Windows PC's where a PLC could do the job far better and without
point-and-drool.)
PLCs to control the process and PCs to monitor the process. I don't know
that I want Vista in charge. It might be only a tool, but that tool might be
very expensive.
IMHO if you are interested in PDP-14 you must
also be interested in early
Modicon PLC's, which were far more common, predate the PDP-14, used core
memory like the PDP-14, and which the PDP-14 was pretty much a clone of. I
think Modicon was also a Massachusets company like DEC.
The cool thing about MODICON is that a simple protocol that they devised
has been widely implemented. It has become a least common denominator
language for communication between devices and controllers.
-chuck