A Tribute to

Dr. J. Presper Eckert

Co-Inventor of ENIAC






The Past Year and a Half


         Pres's Childhood


The Moore School


The Eckert-Mauchly Computer Corporation




Cool Stuff






The Last Page


Accumulator Decade Plug-in Unit

This is a photo from the University of Pennsylvania's web site:

This is the primary computing element from the ENIAC. There is an interesting description of Pres' effort to design this modular component in Scott McCartney's book ENIAC: The Triumphs and Tragedies of the Worlds First Computer. The "ring counter", as it's also known, being offered for sale was used in the famous Honeywell vs. Sperry patent trial. Included in the auction is an original blue line drawing of the plug-in unit with changes hand-marked on it in. Here are some details from from the ring counter:

PI Unit Detail-2.JPG (19531 bytes) PI Unit Detail-3.JPG (27610 bytes) PI Unit Detail-Name.JPG (29015 bytes)

Here I am holding the ring counter.  I had to get a photo of me with it before I packed it up and shipped it to Boston for the sale;

Dan with Ring Counter.JPG (46442 bytes)
Photo by Francis X. Czabator 2000 

All text and images unless otherwise noted 2000 Daniel F. McGrath, Jr.