6 Apr
2013
6 Apr
'13
2:29 p.m.
On 04/06/2013 03:53 PM, Christian Gauger-Cosgrove wrote:
On 6 April 2013 13:59, David Riley <fraveydank at
gmail.com> wrote:
The 11/23 was sole in many variants and price points including raw boards
for OEM system integrators (Bridgeport machine tool for example).
the initial 11/23 was avaiable with and without MMU the non mmu part
was close to using the 11/2 also 16bit. Early MMUs had apparently a
bug and were limited to full performance 18bits. Later production was
full 22bit.
I actually have all varient of the LSI-11 (11/03), F11 (11/23) and a
few J11(11/73) plus the T11 (falcon KXT11).
I wouldn't swear to the fact that there
weren't 11/23s sold as 18-bit
systems; my fuzzy memory says that 11/23 might have been 18-bit while
11/23+ would have been 22-bit. Other people doubtless know better
than me; my other recollection is that the "plus" distinction has to
do with the KDF11-B board (which has the boot ROM and SLUs).
I don't know anything about how DEC sold their machines, but I do believe
they
did sell the 11/23 as an 18-bit system (even though the KDF11A is very
much capable of 22-bit), as I remember there is a "PDP-11/23" version of
the BA11-N box (with H9273-A, the BA11-N always has the H9273-A; except
special OEM boxes that might just have an H9275-A -- or a hobbyist (or company that was too cheap/clever to get a 23+ box)
who has upgraded their
BA11-N to an H9275-A); as well as a "PDP-11/03L" version of the BA11-N box
(the difference between the two being only the front plate, which on the
11/03-L version is all white, including the "background" of the logotype,
while the 11/23 has the "background" of the logo painted black (to make it
more visible)).
There were outside companies that built custom system s but DEC had
their own
groups (computer special systems CSS). Other that came to mind were
Charles River Data systems where the CPU was DEC and the rest was a mix of
compatible boards and other third party boards (Amperx, CRDS, CMD...)
and boxes.
The 11/23+ comes in the BA11-S box, which while also a 9-slot long
backplane, is the H9276-A backplane which is by default a Q22/CD backplane;
I don't think the H9275-A can fit into a BA11-S box, though.
Also the BA11 box is existent in not less than 5 or more flavors with
varying
backplanes, power supplies, and distribution panels. Many evolved over
time.
I have BA11S that (factory) have at least four different backplanes. I also
live 10 MI from DEC and worked there for 10 years.
The H9275 can be fitted, the standard connecting cables may or may not
match up but can be had made easily.
I've even put the backplane from the BA32 in a BA11. The form caxtor is
very standardized though the interconnect for power varies with molex or
terminal barrier strips being used.
I really want to get my hands on a PDP-11/03L version of the BA11-N box;
I'm still trying to replace my "lost" PDP-11 system, and at present all
I've got is a CPU and an H9275-A backplane. (I like the "all white" front
plate, looks nicer in my opinion.) Nevermind that though, I'm going astray
of the original topic.
The original had the black plate the later ones were white and part of
the then
"corporate cabs" in 30, 40, 50, 60 and 72 inch heights. The difference
was the later
racks had rounded corners to the side panels. Never mind the MINC
systems in
their own unique packages.
It's important to know DEC sold "packaged sytems", custom systems and
special
contract systems and the best example of the later being those for
Telephone
company. Any of those found in the wild may have morphed into something
very different from how it was sold.
Allison