Posts: 185
Threads: 20
Joined: Apr 2007
Quote:
Interesting. I hadn't realized unit conversions (English-Metric, that is) had been built in to calculators that early. Looking at the HP-55 features, I was surprised to learn that it included BTU-Joules and LBF-Newtons, whereas most calcs lesser than say, the 28 series, limit themselves to length, mass, volume, and temperature, and only one of each of the aforementioned.
The HP-45 also had a few conversions: cm/in, kg/lb, ltr/gal. But in this case it offered the conversion factors only, one still had to multiply or divide appropriately. The 55 did the math at the push of the button.