Monday, July 13, 2009

Slide Rules and Calculators

I came across this message I had posted in 2007 in another location.

We learned to use slide rules and were required to use them in high school physics (which I took as a junior). Or, it might have been in chemistry which I took as a sophomore. In the physics class, we also had a four-banger calculator at the front of the room that we could use, until someone dropped it. It was large with plasma-segment digits for the display (the big, glowing, orange ones).

We understood well what two- and three-digit precision was. Slide rules also made it pretty easy to understand logarithms. I still think about a slide rule scale when estimating the log of a number from 1 to 10.

My slide rule was a relatively cheap Sterling model, but I was a high school student after all.

When I was a senior, I was given a TI SR-51 calculator as my first calculator. Of course the SR meant ``slide rule.'' It had all of the functions found on a slide-rule and also did hyperbolic trig functions.

The next year, when I was a freshman at Ga Tech, there were still people on campus with slide rules on their belts. Of course, we carried our calculators on our belts, too. The cases had a loop for that purpose.

My roommate, who was an older PhD student, used a slide rule throughout my time at Tech, even in the late 70s. I don't think he actually had a calculator, but I don't remember for sure.

P.S. The SR-51 died before it was two years old and I bought an HP-25 and then upgraded to an HP-25C soon thereafter.