The HP-45 is the second scientific pocket calculator introduced by Hewlett-Packard, adding to the features of the HP-35. It was introduced in 1973[1] with an MSRP of US$395[2] (equivalent to $2,711 in 2023).[3] Especially noteworthy was its pioneering addition of a shift key that gave other keys alternate functions.
The calculator was code-named Wizard,[4] which is the first known use of a code name for a calculator.
It also contained an Easter egg that allowed users to access a not-especially accurate stopwatch mode.[5][6] An accurate version of the stopwatch mode was officially featured in the 1975 successor of the HP-45, the HP-55.
The display of the HP-45 hidden timer showing 00 hours 00 minutes 07 seconds and 58/100 second.
HP-45 functions
Arithmetic
+, −, ×, ÷
Trigonometry
sin, arc sin; cos, arc cos; tan, arc tan (decimal degrees, radians or grads).