ENIAC is considered the world's first computer. An amazing machine--primitive by today's standards. Then again, most things created in 1946 are primitive by today's standards. Sixty years of progress will do that to you.
Here's a very interesting post on ENIAC. It's from Photon Courier, which I'm proud to have on my blogroll.
I remember listening to a talk by Commodore (I love that rank) Grace Hopper, USN, for some class I took at West Point. I don't even remember which course. Anyway, Commodore Hopper talked about her work on ENIAC, a fascinating first-person story from a "little old lady" told as only a little old lady could. What I remember most about this talk was her description of a nanosecond. She couldn't grasp how small a timeframe a nanosecond was, so she calculated how far light (or electricity) would travel in a nanosecond. It came out to about 11.8", and she cut a wire that long to help her "see" a nanosecond. As we left the auditorium, she handed each of us a "nanosecond".
I've long since lost mine. Shame.