The HP-65 is the first magnetic card-programmable handheld calculator. Introduced by Hewlett-Packard in 1974 at an MSRP of $795, it featured nine storage registers and room for 100 keystroke instructions. It also included a magnetic card reader/writer to save and load programs. Like all Hewlett-Packard calculators of the era and most since, the HP-65 used Reverse Polish Notation (RPN) and a four-level automatic operand stack.
The HP 33s (F2216A) was a scientific calculator marketed by Hewlett-Packard. It was introduced in 2003 as the successor to the HP 32SII, and discontinued on the introduction of its successor the HP 35s in 2007.
The HP-41C series are programmable, expandable, continuous memory handheld RPN calculators made by Hewlett-Packard from 1979 to 1990. The original model, HP-41C, was the first of its kind to offer alphanumeric display capabilities. Later came the HP-41CV and HP-41CX, offering more memory and functionality.
The HP-42S RPN Scientific is a programmable RPN Scientific hand held calculator introduced by Hewlett-Packard in 1988.
The HP-27S was a pocket calculator produced by Hewlett-Packard, introduced in 1988, and discontinued between 1990 and 1993. It was the first HP scientific calculator to use algebraic entry instead of RPN, and though it was labelled scientific, it also included features associated with specialized business calculators.
The HP-10B (F1636A) is a student business calculator introduced in 1987. The model of this calculator proved to compete well with the higher end RPN HP-12C.
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. Marketed as a student calculator, the 22S uses infix notation rather than the reverse polish notation used on some higher-end HP calculators of the same era.
The HP-32S was a programmable RPN scientific calculator introduced by Hewlett-Packard in 1988. It was succeeded by the HP-32SII scientific calculator.
The HP-12C is a financial calculator made by Hewlett-Packard (HP) and its successor HP Inc. as part of the HP Voyager series, introduced in 1981. It is HP's longest and best-selling product and is considered the de facto standard among financial professionals. There have been multiple revisions over the years, with newer revisions moving to an ARM processor running a software emulator of the original Nut processor. Critics claim that its 1980s technology is antiquated, but proponents point out that it is still the de facto and de jure in high finance.
HP calculators are various calculators manufactured by the Hewlett-Packard company over the years.
Programmable calculators are calculators that can automatically carry out a sequence of operations under control of a stored program. Most are Turing complete, and, as such, are theoretically general-purpose computers. However, their user interfaces and programming environments are specifically tailored to make performing small-scale numerical computations convenient, rather than general-purpose use.
The Hewlett-Packard Voyager series of calculators were introduced by Hewlett-Packard in 1981. All members of this series are programmable, use Reverse Polish Notation, and feature continuous memory. Nearly identical in appearance, each model provided different capabilities and was aimed at different user markets.
The HP-25 was a hand-held programmable scientific/engineering calculator made by Hewlett-Packard between early January 1975 and 1978. The HP-25 was introduced as a cheaper alternative to the ground-breaking HP-65.
The HP-15C is a high-end scientific programmable calculator of Hewlett-Packard's Voyager series produced between 1982 and 1989.
The HP-16C Computer Scientist is a programmable pocket calculator that was produced by Hewlett-Packard between 1982 and 1989. It was specifically designed for use by computer programmers, to assist in debugging. It is a member of the HP Voyager series of programmable calculators. It was the only programmer's calculator ever produced by HP, though many later HP calculators have incorporated most of the 16C's functions.
The HP-28C and HP-28S were two graphing calculators produced by Hewlett-Packard from 1986 to 1992. The HP-28C was the first handheld calculator capable of solving equations symbolically. They were replaced by the HP 48 series of calculators, which grew from the menu-driven RPL programming language interface first introduced in these HP-28 series.
The HP 35s (F2215A) is a Hewlett-Packard non-graphing programmable scientific calculator. Although it is a successor to the HP 33s, it was introduced to commemorate the 35th anniversary of the HP-35, Hewlett-Packard's first pocket calculator. HP also released a limited production anniversary edition with shiny black overlay and engraving "Celebrating 35 years".
The HP 20b Business Consultant is a financial calculator published in 2008 by Hewlett-Packard. Its function is similar to HP 10bII and includes scientific and statistical functions.
The HP-55 was a programmable handheld calculator, a lower-cost alternative to the HP-65. Introduced by Hewlett-Packard in 1975, it featured twenty storage registers and room for 49 keystroke instructions. Its outward appearance was similar to the HP-65, but its silver band went through between the display and the keyboard like HP-45, and the functions of some keys were different from HP-65, and it did not have a magnetic card reader/writer. Like all Hewlett-Packard calculators of the era and most since, the HP-55 used Reverse Polish Notation (RPN) and a four-level automatic operand stack.
The HP-30 or Spice series are RPN Scientific hand-held calculators introduced by Hewlett-Packard in 1978. Some models are programmable.
