[vcf-midatlantic] MOBIDIC replica project

Evan Koblentz evan at vcfed.org
Tue Nov 28 13:19:19 EST 2017

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 

"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 

 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:



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