Women computers of WWII(Source: Physicist Feminist blog)
However, additional wartime pressure created the need for faster computing. Prof. John Mauchly thought of building a machine to calculate ballistic tables. It was the ENIAC. Engineers at IBM too had built the MARK-I(Automatic Sequence Controlled Computer) by February, 1944. MARK-I could solve a wide variety of problems viz; integral calculus, solutions to simultaneous equations, derivatives etc. In these crisis times, Thomas Watson, the then president of IBM gifted MARK-I to Harvard University in May, 1944.
The NDRC(National Defense Research Committee) established in 1940, engaged the nation's scientific and engineering talent in war-research. NDRC contracts were awarded to universities like Harvard, MIT, generous grants were given. Harvard alone had bagged more than one hundred research projects. One such project was the Bureau of Ships Ordnance Computation Project. The Navy also leased the MARK-I and paid a rent of $800 per month.
The MARK-I had just seventy-two words of storage. Some extremely large problems had to fit in just 72 words of storage. Given these constraints, it was challenging to operate the MARK-I. Hopper found the slowness of programs frustrating. Everybody wrote their own programs to solve a specific problem. Hopper was always looking to speed up the writing of code. She maintained a catalog of sub-routines, which could be reused. Later, if someone wanted to perform the same task, they'd copy the routine into their own program.
Soon, more complex calculations required additional storage space. The MARK-II was built with Two Hundred words of storage. The Mark-II was an electromechanical computer and had 13,000 relays. One day, the MARK-II stopped working, as one of the relays had failed. A moth was caught between the contacts and the operator carefully pulled it out with tweezers. It was taped in the logbook, as the first actual bug found. Hopper and her team may have coined the term computer bugs, meaning a failure.
EMCC had won the contract for building UNIVAC for the Census Bureau and development was underway. The UNIVAC was the first computer to have both commercial and scientific applications. Before UNIVAC, information was recorded on paper tapes in the form of punched-holes. With UNIVAC, information was stored on magnetic metal tapes and mounted on a UNISERVO, which converted it into electrical pulses to be fed to the computer at 12,000 digits/second. Since this speed was much faster than could be achieved manually, the tapes were prepared ahead of time on a UNITYPER. A UNITYPER has a regular type-writer keyboard, a numeric keyboard and a bunch of special keys. The UNIPRINTER was the output device, that essentially read the output magnetic tape and printed it.
A video of the UNIVAC - the Giant Electronic Brain(Source: youtube.com)
In 1952, elections were held in the United States. As the counting of votes began, input vote statistics were fed into the UNIVAC. With 7 per cent of the votes counted, the UNIVAC extra-polated the data and correctly predicted a land-slide victory for Dwight Eisenhower. Nobody believed it could be right, until the results were declared. The UNIVAC had become famous. Insurance company Metropolitan Life(Metlife) used a UNIVAC to print premium notices and processing payroll. Statefarm Mutual Automobile Insurance company used the UNIVAC in its business.
When you prepare for an examination, you'd visit the college library, read, gather infomation and refer different books, journals and then compile your notes. Similarly, the sub-routines in a library have got to be linked to main program before you can run it. Hopper and her team created a software A-0, known to us as compiler to link the sub-routines to the driver-module to make a complete finished program. A-0 was the world's first compiler.
Hopper and her team developed the subsequent versions A-1, A-2 and A-3 of the compiler. The A-2 compiler allowed the programmer to code the problem in a pseudo-language instead of machine language. This paved the way for modern-day programming languages.
There was a pressing need to have a common business language to write programs that ran on any computer. A meeting was convened on 28-29 May, 1959 and it had 7 representatives from the US DoD, 11 users and 15 computer manufacturers. This meeting led to the creation of the CODASYL(Conference on Data Systems Language) committee. Three different groups - short, intermediate and long-range were formed. Grace Hopper was one of the two technical advisers to the CODASYL executive committee. A six-person sub-comittee of the short-range group created the first COmmon Business Oriented Language(Cobol) specifications in October, 1959. Cobol drew inspiration from FLOW-MATIC, its fore-runner. Grace Hopper the inventor of FLOW-MATIC, is the mother of Cobol.