PDP-11/20 vd one that just says pdp 11 what are the date differences?? OEM?
jnc at mercury.lcs.mit.edu
Mon Feb 22 14:42:21 CST 2016
> From: Bill Degnan
>> Yes, detailed histories might (and many do) indicate that the name
>> "PDP-11/10" was originally allocated to what later became the 11/15
> what detailed histories are these that you refer to that say there was
> never a single KA11 11/10 sold, not one installed?
I didn't say that they said "there was never a single KA11 11/10 sold, not
So I just spent an hour looking through all the standard DEC histories (e.g.
Bell, Mudge, McNamara, "Computer Engineering: A DEC View of Hardware Systems
Design", etc, etc, etc, etc, etc) and I was unable to find _anything_ about
either the 'first' -11/10; or even the -11/15, for that matter! So I don't
know where I saw the mention of the 'first' -11/10 being what later became
I _did_ find a mention of the 'first' -11/10 in the 1970 "PDP-11 Handbook"
(pg. 1), with the specs as in the 1969 price list. Unlike the -11/15, which
did have differences in the CPU itself, it seems that the 'first' -11/10
differed from the -11/20 only in the memory that came with it - i.e. the CPU
was the identical KA11 as in the -11/20.
So, do you know of any engineering document or photograph of one of those
'first' -11/10's? My bet is that there probably are none - because the
machine likely never existed. (Although DEC may have sold a few, what was
shipped was probably an -11/20 - with a front panel reading 'PDP-11', which
may be why the earliest -11/20's said that - with the configuration listed
for the 'first' -11/10.)
To repeat: To the extent that one allocates the name "-11/10" to anything, it
should, by virtue of the existence of _many actual physical instances_,
_marked as such_, be to the KD11-B machine.
PS: Amusing factoid: I have a PDP-11/20 price list from April 1, 1972 which
lists a "PDP-11/21"! (Versions are -CA, -CB, -CE, -CF.) It's repeated
multiple places throughout the list, which leads me to believe it's not a
typo.) No idea what that was all about.
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