State of Grace - Embedded.com

State of Grace

Twenty years ago Grace Hopper gave me a nanosecond.

Admiral Hopper is renowned as one of the first women in computing, and was certainly one of the most influential of all computer scientists. One of her 1953 inventions — the compiler — is probably today the most important tool we embedded folks use. Can you imagine being stuck coding in assembly today?

Grace Hopper

Born 97 years ago this week on Dec 9, 1906, she was the third person to join the research team of Professor Howard H. Aiken, who had requested her months earlier and greeted her with the words, “Where the hell have you been?” Then he pointed to the Mark I electromechanical computing machine: “There's the machine. Compute the coefficients of the arc tangent series by next Thursday.”

I once had a boss who gave requirements just as casually. In a half-century the computers have changed beyond all recognition but the personalities not at all.

Active, energetic, she reminded me of Buckminister Fuller, another visionary I had the honor of meeting, and another who is now departed and missed. Though pushing 80 at the time, she was far more dynamic than most of us much younger folks attending her presentation. She gave each of the 20 or so of us there a piece of telephone wire — the solid copper kind with thin, color-coded insulation — that was about a foot long. “It takes electricity one nanosecond to propagate through that wire,” she lectured, hoping (successfully) to awe us with the miniscule nature of one nanosecond.

Nowadays, of course, a nanosecond is a huge quantity. My $1,000 desktop cycles at 2.6 GHz, or about 385 picoseconds. Promises of 20 GHz CPUs in the near future will push that to 50 picoseconds. I wonder what the Admiral would have thought of these advances, for she died on January 1, 1992, when desktop machines ran at a paltry ten megahertz (100 nanosecond cycle times) or so.

Yet today I still use her example when explaining the concept of a nanosecond to non-techies. I hold my hands a foot apart, mentally calibrating the distance to the remembered wire. That trivial bit of copper disappeared years ago, probably crinkled into a ball of lab-bench waste. I miss it, for it forged a bit of a connection to the earliest days of computing, and to one of the industry's most interesting people.

The first bug

Admiral Hoper is also credited with finding the first software bug — a moth fried in relay contacts of the Mark I computer. Like original sin, that's another legacy we've inherited — and one none of us relish.

Happy birthday, Grace — we miss you!

Jack G. Ganssle is a lecturer and consultant on embedded development issues. He conducts seminars on embedded systems and helps companies with their embedded challenges. Contact him at . His website is .


Ms. Harper gave me a nano-second too! Her lecture at my jr. high school (late '70s?) was perhaps my earliest introduction to the beginnings and advancement of computers. Even then, she had the forsight to mention the recipe for pico-seconds. Pico-seconds just are not as handy to give away at a lecture. However, if you want to make pico-seconds, just give the knob of your pepper mill a turn. You'll make lots of little pico-seconds.

– Greg Feneis

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.