DALLAS — Jerry Merryman, one of the inventors of the hand-held electronic calculator who is described by those who knew him as not only brilliant but also kind with a good sense of humor, has died. He was 86.

He’s one of the three men credited with inventing the hand-held calculator while working at Dallas-based Texas Instruments. The team was led by Jack Kilby, who made way for today’s computers with the invention of the integrated circuit and won the Nobel Prize. The prototype built by the team, which also included James Van Tassel, is at the Smithsonian Institution.

“I have a Ph.D. in material science and I’ve known hundreds of scientists, professors, Nobel Prize-winners and so on. Jerry Merryman was the most brilliant man that I’ve ever met. Period. Absolutely, outstandingly brilliant,” said Vernon Porter, a former TI colleague and friend.

Merryman told NPR’s “All Things Considered” in 2013, “It was late 1965 and Jack Kilby, my boss, presented the idea of a calculator. He called some people in his office. He says, we’d like to have some sort of computing device, perhaps to replace the slide rule. It would be nice if it were as small as this little book that I have in my hand.”

The Smithsonian says that the men had made enough progress by September 1967 to apply for a patent, which was subsequently revised before the final application in June 1974.