Also, just as an aside, IBM punch cards are getting harder to find and pricy.
Sent from my iPhone > On Sep 3, 2025, at 13:56, Brian L. Stuart via cctalk <[email protected]> > wrote: > > Apologies in advance to anyone who gets this multiple times. > I know a number of you are on more that one of these lists. > > I'm looking for some information on a couple of the early > IBM unit record devices, in particular the Type 512A and > the Type 518. Ideally, I'd like to get the mechanical > dimensions in enough detail to create a CAD model. > > The background is that I'd like to improve the model that > I'm using in my ENIAC simulator and I'm involved with a > school in Arizona that's working on a project to build a > full-scale model of the ENIAC. There's a letter from > IBM in the ENIAC archives that suggest the use of the > 512A and the 518. So I'm pretty sure those are the ones > they used, but I haven't really been able to find any > details about them. We've found a fair amount of > information on the Type 513, and from photographs, the > punch used on the machine seems similar to the 513, but > is smaller. > > Thanks in advance, > BLS >
