Grace Murray Hopper (December 9, 1906 – January 1, 1992) was an American computer scientist and United States Navy Rear Admiral. A pioneer in the field, she was one of the first programmers of the Harvard Mark I computer, and developed the first compiler for a computer programming language. She conceptualized the idea of machine-independent programming languages, which led to the development of COBOL, one of the first modern programming languages. She is credited with popularizing the term "debugging" for fixing computer glitches (inspired by an actual moth removed from the computer). Owing to the breadth of her accomplishments and her naval rank, she is sometimes referred to as "Amazing Grace". The U.S. Navy destroyer USS Hopper (DDG-70) is named for her, as was the Cray XE6 "Hopper" supercomputer at NERSC.
UNIVAC
In 1949, Hopper became an employee of the Eckert-Mauchly Computer Corporation as a senior mathematician and joined the team developing the UNIVAC I.[12] In the early 1950s the company was taken over by the Remington Rand corporation and it was while she was working for them that her original compiler work was done. The compiler was known as the A compiler and its first version was A-0.[15]:11
In 1952 she had an operational compiler. "Nobody believed that," she said. "I had a running compiler and nobody would touch it. They told me computers could only do arithmetic."[16]
In 1954 Hopper was named the company's first director of automatic programming, and her department released some of the first compiler-based programming languages, including MATH-MATIC and FLOW-MATIC.[12]
COBOL
In the spring of 1959, a two-day conference known as the Conference on Data Systems Languages (CODASYL) brought together computer experts from industry and government. Hopper served as the technical consultant to the committee, and many of her former employees served on the short-term committee that defined the new language COBOL (an acronym for COmmon Business-OrientedLanguage). The new language extended Hopper's FLOW-MATIC language with some ideas from the IBM equivalent, COMTRAN. Hopper's belief that programs should be written in a language that was close to English rather than in machine code or languages close to machine code (such as assembly language) was captured in the new business language, and COBOL would go on to be the most ubiquitous business language to date.[17]
From 1967 to 1977, Hopper served as the director of the Navy Programming Languages Group in the Navy's Office of Information Systems Planning and was promoted to the rank of captain in 1973.[14] She developed validation software for COBOL and its compiler as part of a COBOL standardization program for the entire Navy.
Anecdotes
Throughout much of her later career, Grace Hopper was much in demand as a speaker at various computer-related events. She was well known for her lively and irreverent speaking style, as well as a rich treasury of early war stories. She also received the nickname "Grandma COBOL".
- While she was working on a Mark II Computer at a US Navy research lab in Dahlgren, Virginia in 1947, her associates discovered a moth stuck in a relay and thereby impeding operation, whereupon she remarked that they were "debugging" the system. Though the term bug had been in use for many years in engineering[36][37] to refer to small glitches and inexplicable problems, Admiral Hopper did bring the term into popularity.[38] The remains of the moth can be found in the group's log book at the Smithsonian Institution's National Museum of American History in Washington, D.C.[39]
- Grace Hopper is famous for her nanoseconds visual aid. People (such as generals and admirals) used to ask her why satellite communication took so long. She started handing out pieces of wire which were just under one foot long (11.80 inches), which is the distance that light travels in one nanosecond. She gave these pieces of wire the metonym "nanoseconds."[22] She was careful to tell her audience that the length of her nanoseconds was actually the maximum speed the signals would travel in a vacuum, and that signals would travel more slowly through the actual wires that were her teaching aids. Later she used the same pieces of wire to illustrate why computers had to be small to be fast. At many of her talks and visits, she handed out "nanoseconds" to everyone in the audience, contrasting them with a coil of wire nearly a thousand feet long, representing a microsecond. Later, while giving these lectures while working for DEC, she passed out packets of pepper which she called picoseconds.
Jay Elliot described Grace Hopper as appearing to be "'all Navy', but when you reach inside, you find a 'Pirate' dying to be released".[40]
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