HP-20S

Last updated

HP-20S
HP-20S.jpg
The HP-20S
Type Programmable scientific
Manufacturer Hewlett-Packard
Introduced1989
Discontinued2000
Cost$50
Calculator
Entry mode Infix
Precision12 display digits (15 digits internally), exponent ±499
Display type LCD seven-segment display
Display size1 line
CPU
Processor Saturn (Bert)
Frequency640 kHz
Programming
Programming language(s)key stroke
Firmware memory10 KB of ROM
Program steps99
Other
Power supply3×1.5V button cell batteries (Panasonic LR44, Duracell PX76A/675A or Energizer 357/303)
Weight4.2 oz (120 g)
Dimensions148×80×15mm

The HP-20S (F1890A) is an algebraic programmable scientific calculator produced by Hewlett-Packard from 1987 to 2000.

Contents

A member of HP's Pioneer series, the 20S was a low cost model targeted at students, using the same hardware as the HP-10B business calculator. Compared with the higher-end 32S and 42S scientific calculators, the 20S includes much more basic functionality. As a student calculator, it also uses infix notation rather than the Reverse Polish notation found in higher-end HP calculators.

Despite these limitations, the 20S is keystroke programmable, supporting up to 99 program lines of fully merged instructions and ten memory registers.

Hardware

Introduced at the 1989 Consumer Electronics Show, the HP 20S had an initial retail price of 50 USD. Introduced simultaneously was the HP-10B, based on the same hardware but targeting the business calculator market. The retail price set a new bar for HP, who credited their delivery of a low-price product to tight integration between their research, development and manufacturing departments. [1]

The 20S has the same physical form factor and 37-key keypad as other models in the Pioneer series. The CPU is an HP Saturn (Bert) chip clocked at 640 kHz. With only 256 bytes of RAM, the 20S is at the bottom end of the HP Pioneer range.

While higher end scientific models in the Pioneer series were fitted with dot-matrix displays that allowed their functionality to be organized into menus (the 22S, 32S and 42S being examples), the 20S has only a more primitive 12-digit seven-segment display. Advanced functionality is therefore accessed by a pair of shift keys, with almost every key on the keypad assigned secondary and tertiary functions.

The initial design used blue and orange shift keys, but a visual refresh in 1999 changed the color scheme to green and purple.

Critical evaluation

A 1994 evaluation of contemporary calculators criticized some of the features and quirks of the HP 20S. [2] Some points of criticism included:

Despite these criticisms, the same source had praise for the calculator's accuracy (rounding errors produced by other calculators did not occur), and for the quality of the HP 20S user manual.

Program library

The 20S contained six preloaded programs in ROM for common mathematical operations. These programs could be loaded to RAM and used and edited as user programs.

The program library was used by HP as a key feature for advertising the 20S. [3]

HP-21S

HP-21S Hp-21s.jpg
HP-21S

The HP 21S is a variant of the 20S designed specifically for statistical calculations. HP's stated goal in releasing the 21S was to eliminate the need for statistics tables, just as the HP-35 had previously eliminated for trigonometric and log tables. [4] [5]

The majority of the features of the 20S are still present, including keystroke programming support and the typical trigonometric, logarithmic and exponential functions found on most scientific calculators. However, the 21S has several features specifically to support statistical analysis:

To accommodate the extra functionality, the 21S sacrifices some of the 20S's functionality; specifically it does not support base arithmetic and unit conversions, along with hyperbolic functions.

Libraries

See also

Related Research Articles

<span class="mw-page-title-main">Scientific calculator</span> Calculator designed to calculate problems in science, engineering, and mathematics

A scientific calculator is an electronic calculator, either desktop or handheld, designed to perform calculations using basic and complex mathematical operations and functions. They have completely replaced slide rules and are used in both educational and professional settings.

<span class="mw-page-title-main">HP-65</span> Programmable handheld calculator with magnetic card reader

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.

<span class="mw-page-title-main">HP 33s</span>

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.

<span class="mw-page-title-main">HP-41C</span> Hewlett-Packard handheld RPN calculator

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.

<span class="mw-page-title-main">HP-42S</span>

The HP-42S RPN Scientific is a programmable RPN Scientific hand held calculator introduced by Hewlett-Packard in 1988. It has advanced functions suitable for applications in mathematics, linear algebra, statistical analysis, computer science and others.

<span class="mw-page-title-main">HP-27S</span>

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.

<span class="mw-page-title-main">HP-22S</span>

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.

<span class="mw-page-title-main">HP-32S</span>

The HP-32S was a programmable RPN Scientific Calculator introduced by Hewlett-Packard in 1988 and discontinued in 1991. It continued the tradition of the HP-15C programmable RPN Scientific Calculator. But some functions of the HP-15C were omitted and some were reduced in functionality, so to some extent it is more correct to say that the HP-32S expanded upon the HP-34C. It supported complex math, statistics, probability, and other functions.

<span class="mw-page-title-main">HP-12C</span> Financial calculator made by Hewlett-Packard

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.

<span class="mw-page-title-main">HP calculators</span> Calculator product line by Hewlett-Packard

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.

<span class="mw-page-title-main">HP-25</span>

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.

<span class="mw-page-title-main">HP-15C</span> Programmable scientific calculator produce by Hewlett-Packard

The HP-15C is a high-end scientific programmable calculator of Hewlett-Packard's Voyager series produced between 1982 and 1989.

<span class="mw-page-title-main">HP-16C</span> Programmable calculator produce by Hewlett-Packard

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.

<span class="mw-page-title-main">HP-28 series</span> Series of graphing calculators produced by Hewlett-Packard

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.

<span class="mw-page-title-main">HP-27</span>

The HP-27 was a hand-held scientific and financial, but not programmable, calculator made by Hewlett-Packard between 1976 and 1978.

<span class="mw-page-title-main">HP 35s</span> Programmable scientific calculator produced by Hewlett-Packard

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".

<span class="mw-page-title-main">HP 20b</span>

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.

<span class="mw-page-title-main">HP-55</span>

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.

<span class="mw-page-title-main">HP 30 series</span>

The HP-30 or Spice series are RPN Scientific hand held calculators introduced by Hewlett-Packard in 1978. Some models are a programmable.

References

  1. "More calculators". Analog Computing Magazine. JE Publishers. May 1989. p. 14. Retrieved 2022-02-23.
  2. Harold Thimbleby (1994-07-25). "A new calculator and why it is necessary". The Computer Journal. 38 (6): 418–433.
  3. "For $49.95, no other calculator comes with a program library". Scientific American . 260 (2): 13. February 1989.
  4. "Calculator Replaces Statistics Tables". Science . 244 (4904): 593. 1989-05-05.
  5. "New calculator is said to eliminate statistics tables in college courses". Educational Technology. 29 (5): 4. May 1989.