On Tue, Oct 18, 2016 at 11:13 PM, Evan Koblentz via vcf-midatlantic < vcf-midatlantic@lists.vintagecomputerfederation.org> wrote:
Way back when the old MARCH opened its first exhibit at InfoAge (2005), the InfoAge powers that be lent us a collection to curate from an IEEE life fellow named Dimitry Grabbe. Among the collection was a board of tubes which Mr. Grabbe said was a half-adder module from the ENIAC.
We soon figured out that Grabbe was wrong. The board says Engineering Research Associates. ERA had no part in ENIAC. Remington Rand bought ERA around the same time as RR also bought Eckert-Mauchly Computer Company. ERA + EMCC jointly became the UNIVAC division of Remington Rand.
Thus my working theory has been that the part is from an early-model UNIVAC, although there was a slight chance it was an ENIAC replacement part.
ERA was in Minnesota. Their alumni group has been nice to us. Two of their members spoke at VCF East 7.0, they gave us some artifacts (most notably a UNIVAC 1 technical manual), and there are links to us at http://vipclubmn.org/Exhibits.html#Others.
Tonight I stumbled onto this link: http://vipclubmn.org/Articles/ERA2unisysWeb.pdf
Go to page 4 of the PDF (page 2 of the document) -- look at the picture on the shelves on the right -- it's a plugboard of tubes from a UNIVAC 1103, circa 1955.
That is EXACTLY the part we have from Grabbe!
They describe it as the "basic logic element". I don't know where Grabbe got "half adder" but, as experienced/smart as he was, I trust the guys who built the computer.
It's already in our new display case and soon there will be an accurate sign with it. :)
Here's a picture of an 1103 in full glory: https://upload.wikimedia.org/wikipedia/commons/2/2c/UNIVAC-1 103-BRL61-0905.jpg
that's a cool story FYI, ERA is also where the fledgling, enthusiastic engineer by the name of Seymour Cray had his start -- and the rest is history. A really good book about their behind the scenes work from their WWII start and later on to CDC is called 'Engines of the Mind' Dan