Computing History Timeline
Grace Murray Hopper
Contents
Programming the first computers
Early compilers and validation
UNIVAC
In 1949, Grace Murray Hopper became an employee of the Eckert-Mauchly Computer
Corporation and joined the team developing the UNIVAC I. 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. Later versions were
released commercially as the ARITH-MATIC, MATH-MATIC and FLOW-MATIC compilers.
COBOL
She later returned to the Navy where she worked on validation software for the programming language COBOL and its compiler. COBOL was defined by the CODASYL committee which extended her FLOW-MATIC language with some ideas from the IBM equivalent, the COMTRAN. However, it was her idea that programs could 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), which is how it was normally done at that time. It is fair to say that COBOL was based very much on her philosophy.
Standards
In the 1970s, she pioneered the implementation of standards for testing computer systems and components, most significantly for early programming languages such as FORTRAN and COBOL. The Navy tests for conformance to these standards led to significant convergence among the programming language dialects of the major computer vendors. In the 1980s, these tests (and their official administration) were assumed by the National Bureau of Standards (NBS), known today as the National Institute of Standards and Technology (NIST).
Programming the First Computers
Perseverance was on of the personality traits that made Grace Murray Hopper a
great leader. On her arrival at Cruft Laboratory she immediately encountered the
Mark I computer. For her it was an attractive gadget, similar to the alarm
clocks of her youth; she could hardly wait to disassemble it and figure it out.
Admiral Hopper became the third person to program the Mark I. She received the
Naval Ordnance Development Award for her pioneering applications programming
success on the Mark I, Mark II, and Mark III computers.
A true visionary, Admiral Hopper conceptualized how a much wider audience could
use the computer if there were tools that were both programmer-friendly and
application-friendly. In pursuit of her vision she risked her career in 1949 to
join the Eckert-Mauchly Computer Corporation and provide businesses with
computers. There she began yet another pioneering effort of UNIVAC I, the first
large-scale electronic digital computer. To ease their task, Admiral Hopper
encouraged programmers to collect and share common portions of programs. Even
though these early shared libraries of code had to be copied by hand, they
reduced errors, tedium, and duplication of effort.
By 1949 programs contained mnemonics that were transformed into binary code
instructions executable by the computer. Admiral Hopper and her team extended
this improvement on binary code with the development of her first compiler, the
A-O. The A-O series of compilers translated symbolic mathematical code into
machine code, and allowed the specification of call numbers assigned to the
collected programming routines stored on magnetic tape. One could then simply
specify the call numbers of the desired routines and the computer would "find
them on the tape, bring them over and do the additions. This was the first
compiler," she declared.
Admiral Hopper believed that the major obstacle to computers in non-scientific
and business applications was the dearth of programmers for these far from
user-friendly new machines. The key to opening up new worlds to computing, she
knew, was the development and refinement of programming languages - languages
that could be understood and used by people who were neither mathematicians nor
computer experts. It took several years for her to demonstrate that this idea
was feasible.
Early Compilers and Validation
Pursuing her belief that computer programs could be written in English, Admiral hopper moved forward with the development for Univac of the B-O compiler, later known as FLOW-MATIC. It was designed to translate a language that could be used for typical business tasks like automatic billing and payroll calculation. Using FLOW-MATIC, Admiral Hopper and her staff were able to make the UNIVAC I and II "understand" twenty statements in English. When she recommended that an entire programming language be developed using English words, however, she "was told very quickly that [she] couldn't do this because computers didn't understand English." It was three years before her idea was finally accepted; she published her first compiler paper in 1952.
Admiral Hopper actively participated in the first meetings to formulate specifications for a common business language. She was one of the two technical advisers to the resulting CODASYL Executive Committee, and several of her staff were members of the CODASYL Short Range Committee to define the basic COBOL language design. The design was greatly influenced by FLOW-MATIC. As one member of the Short Range Committee stated, "[FLOW-MATIC] was the only business-oriented programming language in use at the time COBOL development started... Without FLOW-MATIC we probably never would have had a COBOL." The first COBOL specifications appeared in 1959.
Admiral Hopper devoted much time to convincing business managers that English language compilers such as FLOW-MATIC and COBOL were feasible. She participated in a public demonstration by Sperry Corporation and RCA of COBOL compilers and the machine independence they provided. After her brief retirement from the Navy, Admiral Hopper led an effort to standardize COBOL and to persuade the entire Navy to use this high-level computer language. With her technical skills, she lead her team to develop useful COBOL manuals and tools. With her speaking skills, she convinced managers that they should learn to use them.
Another major effort in Admiral Hopper's life was the standardization of compilers. Under her direction, the Navy developed a set of programs and procedures for validating COBOL compilers. This concept of validation has had widespread impact on other programming languages and organizations; it eventually led to national and international standards and validation facilities for most programming languages.
Recognition
Admiral Grace Murray Hopper received many awards and commendations for her accomplishments. In 1969, she was awarded the first ever Computer Science Man-of-the-Year Award from the Data Processing Management Association. In 1971, the Sperry Corporation initiated an annual award in her name to honor young computer professionals for their significant contributions to computer science. In 1973, she became the first person from the United States and the first woman of any nationality to be made a Distinguished Fellow of the British Computer Society.
After four decades of pioneering work, Admiral Hopper felt her greatest contribution had been "all the young people I've trained." She was an inspirational professor and a much sought-after speaker, in some years she addressed more than 200 audiences. In her speeches Admiral Hopper often used analogies and examples that have become legendary. Once she presented a piece of wire about a foot long, and explained that it represented a nanosecond, since it was the maximum distance electricity could travel in wire in one-billionth of a second. She often contrasted this nanosecond with a microsecond - a coil of wire nearly a thousand feet long - as she encouraged programmers not to waste even a microsecond.When Admiral Grace Murray Hopper died, the world lost an inspiration to women and scientists everywhere. Her outstanding contributions to computer science benefited academia, industry, and the military. Her work spanned programming languages, software development concepts, compiler verification, and data processing. Her early recognition of the potential for commercial applications of computers, and her leadership and perseverance in making this vision a reality, paved the way for modern data processing.
Bibliography
Wikipedia
http://en.wikipedia.org/wiki/Grace_Murray_Hopper
Grace Murray Hopper
http://cs-www.cs.yale.edu/homes/tap/Files/hopper-story.html
