HP-27S
The HP-27S was a pocket calculator produced by Hewlett-Packard, introduced in 1988, and discontinued between 1990 and 1993 (sources vary). 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 device featured standard scientific functions, including statistics and probability.
Also recorded as HP27S
HP-27S
Lukke · Public domain
- Name
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- calculator
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In this article
Overview
Overview
Equations could be stored in memory, and solved and integrated for specified variables. Binary, octal, and hexadecimal number bases could be used. Business features included a real-time clock and calendar with up to ten appointments (each with a 22 character message string), as well as functions such as time value of money calculations. The 27S was not programmable in the conventional way, but it included an advanced formula-storage system with programming features. Within stored formulas, sub-formulas could be defined and later referred to by name. Loops and conditional execution could also be embedded within formulas.
Here's a fairly well-preserved machine from 1987. The HP-27S is called the first algebraic pocket scientific calculator from HP. They are best known for the RPN logic.
striegel · HP 27S Scientific calculator, front, power on, end of keyboard test, on blue background
Key facts
Key facts
• Name — HP-27S • Type — Scientific • Entry — Infix • Manufacturer — Hewlett-Packard • Introduced — 1988 • Discontinued — 1990-1993 • Processor — Saturn (Lewis) • Frequency — 1 MHz • Precision — 12 display digits (15 digits internally), exponent ±499 • Display Type — LCD dot-matrix • Display Size — 2 lines, 22 characters, 131×16 pixels • Memory Rom — 64 KB of ROM • Memory User — 8 KB • Ports — IR (Infrared) printing • Supply — 3×1.5V button cell batteries (Panasonic LR44, Duracell PX76A/675A or Energizer 357/303) • Weight — 6 oz • Dimensions — 148×80×15mm
Hardware
Hardware
The 27S has the same physical form factor and 37-key keypad as other models in the Pioneer series. Introduced at the same time as the HP-17B, it shares the same internal hardware. The calculator had 6,900 bytes of usable memory, shared among variables and formulas. Ten storage registers R0 through R9 could each hold one number. Its hardware features included a dot-matrix display of two rows of 22 characters. Depending on context, either the top row was used to display the current expression or a message, or the bottom row was used to show menu options, which could be selected with the corresponding keys. An infra-red transmitter was also included, allowing the machine to be used with a compatible printer, such as the HP 82240B. A beeper could be used to sound date/time alarms.
Text attribution
Licensing
Text attribution
Part of the biographical narrative on this page reuses licensed material. Its origin, revision and licence are recorded here.
The biographical narrative on this page is based on the Wikipedia article HP-27S, revision 1353088050 (EN edition), by its contributors. VALÉORINE has edited that text and built its own documentary record around it. The reused material is available under CC BY-SA 4.0, and this page's reuse of it is offered under the same licence. Everything else on this page — the chronology, the holdings, the evidence, the plates and the connections — is VALÉORINE's own record. Sources and licences.
Notes from the source article
Cited by Wikipedia
Notes from the source article
These works are cited by the source article, in its own numbering. They are recorded as its citations, not as sources VALÉORINE has verified.
- 1.Hewlett-Packard Co. HP-42S RPN Scientific Calculator – Owner's Manual. 3. June 1988.
- 2.Hicks, David G. HP-27S. Museum of HP Calculators.
- 3.Bucknall, Julian. My first HP calculator: HP-27S. 2012-02-17.
- 4.Toth, Viktor. Hewlett-Packard HP-27S.
- 5.New HP calculators. Electronics& Technology Today. 7. March 1988.
- 6.Thimet, Tony. HP-27S.
The Encyclopedia exists whether or not anything is for sale. Corrections are recorded rather than overwritten, and every version of this record is kept. Published 16 August 2026.
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