He, Mr. Kilby and Mr. Van Tassel initially built a prototype, which spanned an entire room at their Texas Instruments lab. Then, over the next two years, they packed the same circuit design into a hand-held casing using microchips.
The device had 18 keys, and it could handle addition, subtraction, multiplication and division, printing calculations on a tiny spool of paper. It reached the market in 1970 after Texas Instruments licensed the technology to Canon, carrying a $400 price tag. Soon a second partner, Bowmar, introduced a $250 version called the Bowmar Brain.
Over the next few decades, these devices got smaller and prices continued to drop, and the pocket calculator became a nearly ubiquitous household item. It lost its place in American homes only after the arrival of the Apple iPhone and other smartphones a decade ago.
In addition to his wife, Mr. Merryman is survived by his daughter, Melissa Merryman; his stepdaughter, Kim Ikovic; and two granddaughters. His two previous wives, Vernette (Posey) and Sally (Simon) Merryman, died before him.
During his brief stint at Texas A&M, Mr. Merryman entered a contest alongside 600 other students. They competed to see who was best at using a slide rule, the wood and plastic device that helped with multiplication, division, trigonometry and other mathematical calculations.
After buying a used slide rule for $6, Mr. Merryman won the contest with a nearly perfect score. “Hearne Student ‘Pulverized ′em’ in A&M Contest,” the headline in the local paper read.
Just a few years later, he helped make the slide rule obsolete.