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From: Eric Smith on 15 Feb 2007 19:43
Gregg Townsend wrote:
> Hmmm. There was an article in the January 1978 issue of Communications
> of the ACM entitled "The Evolution of the DECsystem 10". The authors
> were Bell, Kotok, Hastings, and Hill. According to Table I, the PDP-3
> was a "Paper machine", and the price column is left blank.

The PDP-2 designation was for a 24-bit machine that apparently was
never designed.

The PDP-3 archtecture (36-bit) was specified, and it was basically
a PDP-1 stretched to double the word width:

http://bitsavers.org/pdf/dec/pdp3/PDP-3_PrelimSpec.pdf

It is unclear whether DEC did any logic design for the PDP-3, though it
would have been quite easy to base a PDP-3 design on the existing PDP-1
design. A DEC customer built a PDP-3, and this is the machine whose
whereabouts are being questioned.

The second 36-bit architecture DEC designed was used for the PDP-6
and PDP-10, and is a *much* better architecture than that of the
PDP-3.
From: bob on 17 Feb 2007 19:49
Paul Repacholi wrote:
> "Paul A. Suhler" <suhler(a)ieee.org> writes:
>
>> So, the A-12 was the single seater for the CIA and the R-12 (better
>> known as the SR-71) was the two-seater for the USAF.
>
> Grief, this story changes every time you look at it!
>
> From What I know, the A-11 was a CIA funded single seater with metal
> vertical stabs and some other change I can't recall. The 12 was USAF
> funded, 2 seats, or at least the NASA doc on the F-12 showed the
> rear cockpit, in overflight recon and intercepter, YF-12A, forms.
>
> The R-12 moniker is a new one to me.
>
> The odd thing is, the A-11 was quite frequently mentioned all over the
> place along with the A-12 until some time in the 90s when the 11 seems
> to have had a pall of `not been' cast over it.
IIRc, there was another A12, a USN effort in the 80-90s, that was
cancelled. That maybe a source of confusion and coincides with yoru
dates Paul.
From: Erik Magnuson on 18 Feb 2007 15:34
Paul Repacholi wrote:
> "Paul A. Suhler" <suhler(a)ieee.org> writes:
>
>
>>So, the A-12 was the single seater for the CIA and the R-12 (better
>>known as the SR-71) was the two-seater for the USAF.
>
>
> Grief, this story changes every time you look at it!
>
> From What I know, the A-11 was a CIA funded single seater with metal
> vertical stabs and some other change I can't recall. The 12 was USAF
> funded, 2 seats, or at least the NASA doc on the F-12 showed the
> rear cockpit, in overflight recon and intercepter, YF-12A, forms.
>
> The R-12 moniker is a new one to me.
>
> The odd thing is, the A-11 was quite frequently mentioned all over the
> place along with the A-12 until some time in the 90s when the 11 seems
> to have had a pall of `not been' cast over it.

"A-12" is the correct identifier for the single seat recce Blackbird,
apparently the 12th design iteration. A-11 comes from LBJ's dyslexating
AMI (Advanced Manned Interceptor). The SR-71 designation was another LBJ
dyslexiation - the orginal was R/S-71 (Reconnaissance/Strike) with the
"71" to indicate it was following the R/S-70 which was the "new"
nomenclature for the B-70 (ca 1961 or so).

Taking a WAG, the F-12 designator was a shortening of F-112 - but again,
this is a WAG on my part and shouldn't be taken as gospel.

- Erik
From: John Dallman on 18 Feb 2007 21:56
In article <CPOdnQvc4pLsJUXYnZ2dnUVZ_g-dnZ2d(a)speakeasy.net>,
mekire(a)easyspeak.net (Erik Magnuson) wrote:

> "A-12" is the correct identifier for the single seat recce Blackbird,
> apparently the 12th design iteration.

Indeed. As a CIA project, it was outside the usual US military aircraft
designation systems. "A" stood for "archangel", the U2, from the same
Lockheed design group having had the code name of "angel".

> Taking a WAG, the F-12 designator was a shortening of F-112 - but
> again, this is a WAG on my part and shouldn't be taken as gospel.

Nope. They just used the same number when they were considering using it
as a USAF "fighter" - actually more of a high-speed missile platform
than a general-purpose fighter, given its astounding lack of
maneuverability.

--
John Dallman, jgd(a)cix.co.uk, HTML mail is treated as probable spam.
From: Paul Repacholi on 19 Feb 2007 02:37
jgd(a)cix.co.uk (John Dallman) writes:

> In article <CPOdnQvc4pLsJUXYnZ2dnUVZ_g-dnZ2d(a)speakeasy.net>,
> mekire(a)easyspeak.net (Erik Magnuson) wrote:

>> "A-12" is the correct identifier for the single seat recce Blackbird,
>> apparently the 12th design iteration.

> Indeed. As a CIA project, it was outside the usual US military aircraft
> designation systems. "A" stood for "archangel", the U2, from the same
> Lockheed design group having had the code name of "angel".

Thanks for that titbit. Do you have any idea where the name `Dragon Lady'
for the U-2 came from?

>> Taking a WAG, the F-12 designator was a shortening of F-112 - but
>> again, this is a WAG on my part and shouldn't be taken as gospel.

No, it was due to the USAF changing from A-???? to F-???? designations.

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