Today, we look for the first modern digital computer. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

The Sperry-Rand Corporation sued Honeywell in 1967. Honeywell was making digital computers, and Sperry claimed Honeywell owed them a royalty. After WW-II, Sperry had bought the patent rights to ENIAC, the first digital electronic computer. Honeywell came back at Sperry with a countersuit. They made the extraordinary claim that Sperry's patent was invalid -- that the digital computer had already been invented before ENIAC.

Honeywell won its case six years later, and Allan Mackintosh tells us that they did it by correcting history. They found their way back to the winter of 1937. A young physics instructor at Iowa State named John Atanasoff was struggling with the problem of mechanizing computation. Things were going badly this particular evening. Finally, in frustration, he jumped into his car and sped off into the night. Two hundred miles later, he pulled up at a roadhouse in Illinois for something to drink.

And there it came to him. A machine could easily manipulate simple on-off electrical pulses. If computations were done in the "either-or" number base of 2 -- instead of base 10 -- a machine could do calculations naturally. Sitting in that road house, 200 miles from home, he made the crucial step in inventing the digital computer.

Two years later Atanasoff and a colleague named Berry started to build a computer. But in 1942 they were drafted, and the almost-complete computer was set aside without being patented. Meanwhile, the government started work on the ENIAC digital computer. ENIAC differed in some ways, and it was bigger.

Besides, an unfinished, unpatented machine doesn't make a very strong claim in a priority dispute. But there's a catch here. One of the major inventors of ENIAC -- John Mauchly -- had known Atanasoff. They'd corresponded. Mauchly had even visited Atanasoff in Iowa for a week in 1941. In the end, it was clear that the ideas that made ENIAC had come from Atanasoff.

Atanasoff did all his work with only $6000 of grant money. But the military funded the ENIAC project. They wanted to make artillery firing tables, and they put a half-million dollars into ENIAC -- a huge sum in 1942.

So the next time you use your pocket calculator -- the next time you spend 30 seconds doing what would have taken all afternoon -- think about a man clearing his mind one winter night in 1937. Think about a man gazing at a yellow line for five hours, until he was suddenly able to see through the dark.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

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