[vcf-midatlantic] MOBIDIC replica project

Douglas Crawford touchetek at gmail.com
Tue Nov 28 13:39:20 EST 2017

Great idea.
The intersection of computer development and Fort Evans in the MOBIDIC 
is particularly relevant for the museum!

On 11/28/2017 1:19 PM, Evan Koblentz via vcf-midatlantic wrote:
> I want us to build a MOBIDIC replica at the museum.
> Background for any newer list members who aren't aware: MOBIDIC -- 
> Mobile Digital Computer -- was a first-gen (1956) transistor computer 
> designed by the staff of Camp Evans, which is the Army Signal Corps 
> secret electronics R&D facility that's now the InfoAge Science Center, 
> which hosts the VCF museum among many other groups.
> MOBIDIC was not the "first" mobile computer. For example, the National 
> Bureau of Standards (today called NIST) made DYSEAC in 1953. However 
> DYSEAC was a one-time prototype, whereas Sylvania (in Massachusetts, 
> under contract to Camp Evans) built six MOBIDIC computers all of which 
> were successfully used in field operations for several years. Sylvania 
> also made two 9400 computers which were faster versions of the MOBIDIC 
> design.
> "Mobile" is relative. :)  Each MOBIDIC was installed in two 30-ft. 
> trailers. One for the computer itself, one for power, cooling, etc., 
> with the trailers attached by cables/hoses when in use.
> None of the six MOBIDICs or two 9400s exist today.
> Our museum has a beat-up scale model of the computer trailer. Computer 
> History Museum (our friends out in California) have a better model. 
> There are various pictures on the Internet. There are large amounts of 
> public/private documents from the Army/Sylvania about details of the 
> electronic design, architecture, components, programming, etc., most 
> of (all?) of which I obtained while writing my book "Abacus to 
> smartphone: The evolution of mobile and portable computers" published 
> in 2015 (www.abacustosmartphone.com).
> From this information, I believe a replica MOBIDIC could be 
> constructed. At least, a fullish-scale model could be made, and we 
> could let visitors walk inside to see it. At best, someone could 
> emulate the software so the model could "work". (I can't fathom 
> building a complete truly "working" exact clone.)
> Conveniently, there are two 50s/60s-era Army-green trailers parked at 
> InfoAge. They're under control of the electronic warfare group, whose 
> leader (John C.) is a super-nice guy. We get along well. A while ago I 
> asked him if we could use one trailer for this purpose. We "just" need 
> the know-how and money to do it.
> So if we do this, the replica would only be of the computer trailer, 
> not of the support trailer. I envision plenty of signs explaining to 
> visitors that this trailer is HALF an installation.
> I have some ideas about how to fund the project, but there's no point 
> getting into that until we understand how much work is really involved 
> and what it would cost.
> * I wrote "fullish-scale", not full-scale, because I haven't measured 
> the length of the available trailers. It would be close.
> Online images:
> https://en.wikipedia.org/wiki/MOBIDIC#/media/File:MOBIDIC_cutaway.jpg
> https://www.usarmygermany.com/Units/7th%20Army%20SUPCOM/Partials_7th%20ICC%201.htm 

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