Grace Hopper

Humans are allergic to change. They love to say, “We’ve always done it this way.” I try to fight that. That’s why I have a clock on my wall that runs counterclockwise.
Grace Hopper

Grace Murray Hopper (1906-1992)
Grace Murray Hopper (1906-1992)

Rear Admiral Dr. Grace Murray Hopper (1906-1992) was a Ph.D. in mathematics, who devoted almost her entire life to computers and programming. She was one of the most incisive strategic futurists in the world of computing in the middle of the 20th century. Perhaps her best-known contribution to computing was the invention of the first compiler, the intermediate program that translates English language instructions into the language of the target computer.

Hopper started her career in computing in 1943, when she entered the Computation Project at Harvard University, to join the research team of Howard Aiken. Aiken, known to be rough-spoken, greeted her with the words, “Where the hell have you been?”, then pointed to his electromechanical Mark I computer, saying “Here, compute the coefficients of the arc tangent series by next Thursday.”

Hopper quickly plunged in and learned to program the machine, putting together a 500-page Manual of Operations for the Aiken’s computers in which she outlined the fundamental operating principles of computing machines. Later she joined the newly formed Eckert-Mauchly Corporation and remained associated with its successors (Remington-Rand, Sperry-Rand, and Univac) until her official retirement in 1971. There was a funny story from 1947 about Hopper finding the first computer “bug”: a dead moth that had gotten into the Mark I and whose wings were blocking the reading of the holes in the paper tape. In fact, the word “bug” had been used to describe a defect since at least 1889 but Hopper is credited with coining the word “debugging” to describe the work to eliminate program faults.

In 1952, Hopper completed her first compiler (for the Sperry-Rand computer), known as the A-0 System. As she said later, she did this, because she was lazy and hoped that the programmer may return to being a mathematician.

The A-0 System actually was a set of instructions that could translate symbolic mathematical code into machine language. In producing A-0, Hopper took all the subroutines she had been collecting over the years and put them on a tape. Each routine was given a call number so that the machine could find it on the tape. As described by Hopper—”All I had to do was to write down a set of call numbers, let the computer find them on the tape, bring them over and do the additions. This was the first compiler.”

After the A-0, Grace Hopper and her group produced versions A-1 and A-2, improvements over the older version. The A-2 compiler was the first compiler to be used extensively, paving the way for the development of programming languages.

The A-0 System was hardly accepted and dissuaded by the establishment, but Hopper followed her philosophy of “Go ahead and do it. You can apologize later.”. She was disappointed —”I had a running compiler, and nobody would touch it because, they carefully told me, computers could only do arithmetic; they could not do programs. It was a selling job to get people to try it. I think with any new idea because people are allergic to change, you have to get out and sell the idea.”

Hopper also originated the idea that computer programs could be written in English. She viewed letters as simply another kind of symbol that the computer could recognize and convert into machine code. Hopper’s compiler later evolved into the FLOW-MATIC compiler, which will be the base for the extremely important language—COBOL. FLOW-MATIC was aimed at business applications, such as calculating payroll and automatic billing. By the end of 1956, Hopper had UNIVAC I & II understanding of twenty English-like statements using FLOW-MATIC.

Biography of Grace Hopper

Grace Murray in the middle 1920s
Grace Murray in the middle 1920s

Grace Brewster Murray was born on 9 December 1906 in New York. She was the eldest of three children. Her parents, Walter Fletcher Murray (1873-1947) and Mary Campbell Van Horne (1883-1960) were of Scottish and Dutch descent and married in May 1903 in Manhattan. Walter Murray (Yale B.A. 1894, Phi Beta Kappa) was an insurance broker, as his father was before him. Mary Campbell was the daughter of the senior civil engineer of New York City, had always loved mathematics, and instilled this love in her first daughter. Grace had a sister, Mary Campbell (1909–2000), and a brother, Roger Franklin (1911–1998).

In an era when girls were expected to play house, Grace loved climbing trees, hiking, sailing, and reading. She also played basketball, hockey, and water polo, what a strange activity for girls?! She did have a dollhouse but was more interested in building toy furniture for it than in playing with dolls. She even built an elevator for it.

Grace’s parents encouraged her curiosity. They took her to museums, libraries, concerts, and lectures. Grace liked figuring out how things worked. When she was 7, she took apart her alarm clock. Gears and cogs flew out of the clock, but she couldn’t make sense of the mechanism. Instead of giving up, she dismantled all the other alarm clocks in the house, determined to discover how they worked.

Grace Hopper programming a computer
Grace Hopper programming a computer

Unfortunately, when Grace was 8, her father became ill and had to have both legs amputated. He never complained. His bravery inspired Grace to face challenges head-on. If her father could be so brave, Grace felt that she could conquer anything.

Grace’s father worried that he might not always be able to provide for his daughters. He wanted them to get a good education and be able to support themselves. He encouraged them to go to college and envision careers. Grace attended two private schools in New York: The Graham School and Miss Mary Schoonmaker’s School for Girls, then started at Vassar College, a private liberal arts college in Poughkeepsie when she was 17. She graduated from Vassar in 1928 with honors in physics and math and went on to study mathematics at Yale. Getting a master’s degree in 1930, then a Ph.D. in mathematics in 1934, the little girl who’d spent her days tinkering with clocks would become one of the greatest computer minds of her generation.

In 1930 Grace headed back to Vassar College to become a professor in math while also completing a Ph.D. at Yale. While attending Vassar College, Grace met Vincent Foster Hopper (1906–1976), a tall and handsome coeval, who was a professor of literature at New York University. They married in June 1930, but the family didn’t have children and in 1941 separated (finally divorcing in 1945). Although Grace never remarried, she retained his surname.

1959: Grace Hopper on the cover of Time magazine
1959: Grace Hopper on the cover of Time magazine

After the United States’ entry into World War II, Hopper decided to join the war effort. She was initially rejected because of her age and diminutive size (she was 16 pounds underweight for her height of five feet and six inches), but she persisted and eventually received a waiver to join the U.S. Naval Reserve (Women’s Reserve). In December 1943, she took a leave of absence from Vassar, where she was an associate professor, and completed sixty days of intensive training at the Midshipmen’s School for Women at Smith College in Northampton, Massachusetts. After receiving her commission (lieutenant junior grade), Hopper was assigned to the Bureau of Ships Computation Project at Harvard University, where began her long journey in the amazing world of computers.

Following a remarkable career that spanned more than 42 years, Rear Admiral Hopper, nicknamed “Amazing Grace” by her subordinates, took retirement from the Navy in August 1986. Following her retirement from the Navy, Hopper was hired as a senior consultant to Digital Equipment Corporation (DEC).

On New Year’s Day, 1 Jan 1992, Hopper died in her sleep of natural causes at her home in Arlington County, Virginia, at 85 years of age. She was interred with full military honors in Arlington National Cemetery.