On 2025-12-21 6:16 p.m., Brian L. Stuart via cctalk wrote:
So Santa had his sleigh out for some test drives
tonight. For
ballast (the real gifts won't be loaded until Wed night), he used
a big stack of engineering drawings from the 1940s. Fortunately
for us, his "spirited" driving included one turn that was too
tight and out flew the drawings, where they landed on my lap.
Well this is not the first mishap,remember the movie "Santa Claus
Conquers the Martians"
For
anyone who's as eager as I am to geek out over
1940s computer
design, I share them with you here:
http://cs.drexel.edu/~bls96/eniac/drawings/
That was the first computer I knew of was from the 1950's Book of knowledge.
There are over 900 drawings in the set. Most of these
images come
from scans of microfilm taken of the patent trial exhibits. There
are also about 100 copies that the Smithsonian had imaged and put
up on their web site. I've processed them all to approximate
something like we remember from our technical drawing classes in
college (well those of us old enough to have taken them). The
quality varies widely, but a large subset are readable down to
the measurements for the panels and the component values in the
circuits.
If you've read Kathy Kleiman's excellent book (Proving Ground)
about the original ENIAC programmers, you may have found yourself
wondering what the block diagrams from which they figured out how
to program the machine looked like. Well, those are among the
drawings here. So feel free to try your hand at figuing out how
to program it from them.
One subset of the drawings is conspicuous by its absence, the
PX-15 series. From what I can tell, those were drawings of a
delay line memory unit that was never built. Those drawings were
not part of the trial exhibits and were not microfilmed. However,
some physical copies do exist, and I am hoping to get back into
the archives to scan them at some point in the future.
Beyond that, there are a number of drawing numbers that are
skipped, and I suspect that these are drawings that do (or did)
exist, but were not microfilmed for whatever reason. So if anyone
has or comes across any drawings that are not on this list, or
better copies of those that are, feel free to send scans my way.
For anyone wanting to grab copies of the full set, it should be
pretty easy to extract a file name list from the index.html file.
I'll leave the sed command for extracting the list as an exercise
for the reader.
For printing, all of them are sized in the PDF files for 8.5x11
or 11x17 paper. Be warned, printing all of them without duplexing
and folding the 11x17s to fit into a normal binder, ends up
filling 2 4-inch binders.
By the way, if anyone has access to the adapter shown in drawing
PX-4-119, I think there's an error in the drawing and I'd like to
check to see if either there really is or if I'm missing
something.
Thanks and have fun,
BLS
To help with the programming.
https://www.cs.drexel.edu/~bls96/eniac/simulator.html
Ben.