HP-32S

The HP-32S was an inexpensive yet powerful calculator. It had a single line display but with many annunciators to convey additional information. It had a fairly uncluttered keyboard due to its menu system yet it was packed with such features as: Basic scientific functions including hyperbolic functions. Statistics. Probability. Solver (Solved RPN functions.) Numeric integration (of RPN functions.) Binary, octal, decimal and hexadecimal bases. (With windowing to view long binary numbers.) Complex Arithmetic functions (see below.) 390 Bytes of user memory. Variables instead of numbered registers (see below.) Programmability (see below.) Obvious error messages (like Divide By 0.)