HP 22S

The HP-22S is an electronic calculator from the Hewlett-Packard company which is algebraic and scientific. This calculator is comparable to the HP-32S. A solver was included instead of programming. It had the same constraints as the 32S, lacking enough RAM for serious use. Functions available include TVM and unit conversions. Only single letter variable names are allowed.

The HP-22S is a non-RPN calculator unlike most HP calculators. It was the most advanced non-RPN scientific HP calculator available when it was released.