Grace Hopper: Computer Scientist

Grace Hopper: Computer Scientist — page 7 — useful punch cards containing information for UNIVAC Some of the team members were people she had worked with before EMCC was building the first UNIVAC computer which was to be used by the US Census Bureau Hopper and her team made the UNIVAC project a success The computer was able to work with both numerical and alphabetical data inputs It was also the first computer to separate input and output The new computer featured a code that was closer to Hopper’s vision of how humans and computers could communicate John Mauchly wrote the C-10 code assembly language for the UNIVAC I and it has been the basis of most codes since Hopper recalled years later A was add M was multiply B was bring C was clear it was a beautiful code 2 The first UNIVAC computer was delivered to the US Census Bureau in 1951 TEACHING COMPUTERS TO UNDERSTAND HUMANS Hopper continued to think about how to make it faster and easier for humans to work with computers In May 1952 Hopper presented a paper at a meeting of the Association for Computing Machinery in Pittsburgh Pennsylvania The paper outlined a new and radical idea Why not teach machines how to assemble their programs instead of having humans input every step of each program Hopper’s paper suggested 10

Grace Hopper: Computer Scientist — page 8 — that computers could be given sets of instructions on how to perform simple common tasks She called these simple tasks subroutines In many ways programmers were already working in this way Programmers often used the same short sets of instructions to create more complex programs Yet each time they created a new program they had to input the subroutines yet again which took a lot of time and often resulted in mistakes Hopper proposed that these subroutines could be thought about like books in a library Each subroutine told the computer how to do something By organizing the subroutines into a catalog users could tell the computer which subroutines it needed to look up and in what order to do its job Hopper finished her description of this new program generator by The US Census Bureau Computer-Innovation Pioneer EMCC’s first UNIVAC computer was funded by the US Census Bureau Beginning in 1790 the bureau was charged with tracking population demographics to determine how congressional seats should be allocated Yet by 1880 there were more people in the United States than could be effectively counted by the bureau’s manual data-processing abilities As it was 1,500 clerks worked more than seven years to produce the bureau’s report The bureau turned to engineer Herman Hollerith for assistance in tabulating results of the 1890 census Hollerith developed a system to record a person’s identifying information as a series of holes punched in cards which could then be read by machines Hollerith went on to become one of the founders of the company later known as International Business Machines IBM The Census Bureau used UNIVAC to tabulate part of the 1950 population census along with the entire 1954 economic census 11

Grace Hopper: Computer Scientist — page 9 — calling it a compiler That was because it compiled subroutines into a program the same way librarians compile books from a collection into a bibliography Hopper was so excited about her ideas that she made 200 copies of her presentation and left them at the back of the room for people to take However half of them were still there when it was time to leave ADDRESSING THE SKEPTICS Hopper refused to let the lukewarm response stop her from promoting her idea She continued to talk about the benefits of her new system She talked about writing and testing computer programs in hours instead of weeks She noted how the programs would be more accurate too That was because programmers already would have cleaned up any mistakes in the subroutines Some people were excited by Hopper’s ideas Others remained skeptical The skeptics told Hopper that computers could only do arithmetic They could never write their own programs Even Hopper’s employer Remington Rand which had purchased EMCC in 1950 had little interest in Hopper’s ideas Hopper and her colleagues had to work on the project in their spare time By the summer of 1952 they had their first functioning compiler which they named A-0 The A stood for Algebraic They began testing the compiler by pitting it against the work of human programmers One experiment 12

Grace Hopper: Computer Scientist — page 10 — took the UNIVAC with the A-0 compiler less than 49 minutes It took the human programming team 880 minutes to do the same task Compiler versions A-1 and A-2 soon followed Each was a little better than the one before Hopper and her team found themselves talking to buyers of UNIVACs about the benefits of these compilers Computer compilers take the programming language that is produced by people and convert it into the binary language that the machine is able to understand Computers within the same model family would have Meet the UNIVAC UNIVAC was the first mass-produced commercial computer introduced in 1951 A total of 46 UNIVAC I the first generation computers were built In today’s dollars the machine would have cost 7 million The room-sized UNIVAC was 25 feet 7 6 m tall and 50 feet 15 m long and weighed approximately 17,000 pounds 7,711 kg It used 5,600 vacuum tubes 18,000 crystal diodes and 300 relays 3 It was the first computer to have digital magnetic tape though it also could use punch cards Digital magnetic tape was a long narrow strip of plastic film that was coated with a magnetic material Information could be stored on the magnetic tape Users could erase data and reuse the tape to record new data A UNIVAC machine accurately predicted the winner of the 1952 presidential election before the polls closed It did so by running a program that compared the 1952 returns to previous election returns and outcomes to predict which way the election was trending the same low-level language and could use the same compiler This meant that with the use of a compiler a program could work on different machines of the same model That meant less 13

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