The HP-55 Enigma

[Steve Simpkin]

Well despite its limited programming model, it did get you an HP programmable calculator for about the same price as a HP-45 and half the price of a HP-65. It also had a cool (and accurate) timer function and a lot metric conversions which would be very useful when the U.S. changed to the Metric system, which we were assured would only be a matter of days away.

Of course 7 months later the HP-25 came out at half the price of the HP-55. It had 49 fully merged steps and more tests but fewer memories, no timer and no metric conversions. The price of the HP-55 was dropped to $335 about 2 months later.