Dan Cross <crossd at gmail.com> writes:

> On Wed, Dec 18, 2019 at 1:52 PM Paul McJones <paul at mcjones.org>
> wrote:
>
>     Computer History Museum curator Dag Spicer passed along a
>     question from former CHM curator Alex Bochannek that I thought
>     someone on this list might be able to answer. The paper "The M4
>     Macro Processor” by Kernighan and Ritchie says:
>    
>     > The M4 macro processor is an extension of a macro processor
>     called M3 which was written by D. M. Ritchie for the AP-3
>     minicomputer; M3 was in turn based on a macro processor
>     implemented for [B. W. Kernighan and P. J. Plauger, Software
>     Tools, Addison-Wesley, Inc., 1976].
>    
>     Alex and Dag would like to learn more about this AP-3
>     minicomputer — can anyone help?
>
>
> [I recommend that follow-ups go to coff, which is Cc'ed here]
>
> I took a short stab at this, but can find little beyond references in
> the aforementioned M4 paper.
>
> I did, however, run across this: https://www.cia.gov/library/
> readingroom/document/cia-rdp78b04770a000100110018-1
>
> This appears to be a declassified letter written to the US Air Force
> at Bowling Green Air Force Base in regards to spare parts fo the AP-3
> computer; dated October 19, 1966. The list of parts seem reasonable
> for a minicomputer, and it further seems reasonable to believe that
> this may be related to the same type of computer referenced in the M4
> paper. However, details of the sending party have been redacted, and
> there is nothing pointing to the identity of the manufacturer.

Good find. The part numbers suggest Bendix.

> Sadly, that's all that seems available. I wonder if, perhaps, Doug
> McIlroy (Cc'ed directly to float this to the top of his stack) can
> shed more light on the topic?
>
>         - Dan C.
>
>
>

-- 
Alex.