In February 1972, the first relatively affordable and hand-held electronic calculator was made available, for scientists only, priced at $395. Hewlett Packard's HP-35 was the first handheld calculator to perform advanced mathematical functions.
I was in my senior year at NYU Engineering and since my freshman year, I had a totally plastic, cheap, plastic slide rule since I could not afford any of the earlier 1970s calculators like the Canon Pocketronic, Sharp EL-8 or Busicom LE-120A devices that the “rich” kids had. That slide rule got me through my quizzes and tests at NYU to earn me my degree just as well as those fancy, expensive ones by the “Whiz kids”. It was better than an abacus which would have been my second choice or maybe Napier’s Bones from the 1600s, invented by John Napier which was based on a numerical scheme called the Arabian Lattice.
Some people called the slide rule a slipstick, but it was a mechanical “computer” to the EEs on campus at the NYU University Heights campus in the Bronx (Although our campus computer was a Sperry Univac that filled an air-conditioned room with tape drives, punch card programs and we studied Fortran IV programming language in those days). We were allowed to use it during tests because the calculations were the least of your worries in engineering school, it was analyzing and setting up the schematic diagrams using that 1845 German physicist, Kirchoff’s Voltage and Current Laws and later on setting up matrices.
Anyway, it is said that in 1620, William Gunter developed the forerunner to the slide rule—-a logarithmic rule for multiplication and division using dividers.
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