On Wed, 2025-09-03 at 20:48 +0000, Brian L. Stuart via cctalk 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
Contact Dag Spicer <spicer(a)computerhistory.org> at the Computer History
Musum in Mountain View.