I was bored and found a HP-27S

[John R]

(06-09-2014 10:38 PM)jebem Wrote:  Apparently its set of do it all features are enough to take on most of the other HP calculators of its time, almost as powerful as the 42S on scientific features, and showing the shortcomings of machines like the 32S series.

The 27S definitely seems like a hybrid of the 17B and 42S, with maybe 60% of its DNA from the former and 40% from the latter. Which means its numerical designation is particularly fitting, since (0.6 * 17) + (0.4 * 42) = 27.