Thanks, Bill. That's a great resources you've put together. BLS On Sun, Dec 21, 2025 at 08:41:20PM -0500, Bill Degnan via vcf-midatlantic wrote:
Thanks. I added a link to the ENAIC drawings here: https://vintagecomputer.net/browse_thread.cfm?id=147 This is my list of vintage computing-related links.
On Sun, Dec 21, 2025 at 8:15?PM Brian L. Stuart via vcf-midatlantic <vcf-midatlantic@lists.vcfed.org> 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. 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/
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