Hewlett-Packard

To most calculator owners, the name Hewlett-Packard is synonymous with the highest quality in handheld calculating devices. HP can claim many of the firsts in this industry, including the first "shirt-pocket" scientific calculator (HP-35), the first pocket programmable calculator (the HP-65), the first pocket calculator with alphanumeric capability (the HP-41) and more. HP is also one of the few survivors of the "calculator wars" of the 1970s, remaining one of the preeminent calculator manufacturers in 1999. HP calculators are characterized by a very solid physical feel, robust design, great calculation accuracy, and reliable engineering solutions. HP magnetic card readers are a constant source of amazement for me: after their disintegrating transport wheels are repaired, they work like new even after 25 years. My first HP-65, for instance, has not yet had a single faulty read or write operation ever since I fixed its reader in the summer of 1999!

The Keystroke Product Line

The first pocket programmable calculator ever made, Hewlett-Packard's HP-65, already had a very sophisticated programming model. In addition to all the programming advantages offered by the RPN system, it also offered conditional and unconditional branching, labels, subroutines, and a partially merged instruction set. Perhaps it's no wonder that the programming model changed little over the years; its mature version, first introduced with the HP-67, remained largely the same over the years and was still used in HP's last series of RPN keystroke programmables, the Voyager series.

Classics/Topcats

HP's first product line of pocket/portable calculators. Strictly speaking, the HP-67/97/97S actually belong to the second generation: electronically, these machines use the technology of the "Woodstock" series. The appearance of the HP-67 places it in the Classic series, however.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-55HP-55RPN Scientific  10+2 LED digits  Keystroke entry (49 program steps)  Conditionals, Branching  20 numbers  Trigonometrics, Exponentials, Real-time clock 
Hewlett-Packard HP-65HP-65RPN Scientific  10+2 LED digits  Partially merged keystroke (100 program steps)  Conditionals, Branching, Subroutines, Labels  9 numbers  Trigonometrics, Exponentials, Magnetic cards 
Hewlett-Packard HP-67HP-67RPN Scientific  10+2 LED digits  Fully-merged keystroke entry (224 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  26 numbers  Trigonometrics, Exponentials, Magnetic cards 
No Image AvailableHP-95CRPN Scientific  10+2 LED digits  Fully-merged keystroke entry (200 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  17 numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory, Printer 
Hewlett-Packard HP-97HP-97RPN Scientific  10+2 LED digits  Fully-merged keystroke entry (224 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  26 numbers  Trigonometrics, Exponentials, Printer, Magnetic cards 
Hewlett-Packard HP-97SHP-97SRPN Scientific  10+2 LED digits  Fully-merged keystroke entry (224 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  26 numbers  Trigonometrics, Exponentials, Printer, Magnetic cards 

Woodstocks

HP's second pocket product line featured several machines in a very small, pleasant form factor. Unfortunately, the construction of the calculators provided for the uneven heating of the batteries during charging, leading to premature battery wear. The design of the charging circuit also made it possible for the calculator to receive excessive voltage when a battery pack was not properly inserted, causing the calculator's sensitive MOS circuits to fail.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-19CHP-19CRPN Scientific  10(8+2) LED digits  Fully-merged keystroke entry (98 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  30 numbers  Trigonometrics, Exponentials, Continuous memory, Printer 
Hewlett-Packard HP-25HP-25RPN Scientific  10(8+2) LED digits  Fully-merged keystroke entry (49 program steps)  Conditionals, Branching  8 numbers  Trigonometrics, Exponentials 
Hewlett-Packard HP-25CHP-25CRPN Scientific  10(8+2) LED digits  Fully-merged keystroke entry (49 program steps)  Conditionals, Branching  8 numbers  Trigonometrics, Exponentials, Continuous memory 
Hewlett-Packard HP-29CHP-29CRPN Scientific  10(8+2) LED digits  Fully-merged keystroke entry (98 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  30 numbers  Trigonometrics, Exponentials, Continuous memory 

Spice

The third, and last, LED series of calculators from HP were plagued by a different problem. Initially, the calculators' components were held together by pressure; electronic components were not soldered onto the machines' flexible circuit boards. This led to numerous reliability complaints, so eventually HP returned to a more traditional design. The Spice series also featured the first business-oriented programmable machines, as well as HP's most sophisticated scientific calculator to date, the HP-34C.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-33CHP-33CRPN Scientific  10(8+2) LED digits  Fully-merged keystroke entry (49 program steps)  Conditionals, Branching  8 numbers  Trigonometrics, Exponentials, Continuous memory 
Hewlett-Packard HP-33EHP-33ERPN Scientific  10(8+2) LED digits  Fully-merged keystroke entry (49 program steps)  Conditionals, Branching  8 numbers  Trigonometrics, Exponentials 
Hewlett-Packard HP-34CHP-34CRPN Scientific  10(8+2) LED digits  Fully-merged keystroke entry (210 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  21(1) numbers  Trigonometrics, Exponentials, Linear regression, Solver, Integration, Continuous memory 
Hewlett-Packard HP-38CHP-38CFinancial  10(8+2) LED digits  Fully-merged keystroke entry (99 program steps)  Conditionals, Branching  20(7) numbers  Exponentials, Linear regression, Financial, Continuous memory 
Hewlett-Packard HP-38EHP-38EFinancial  10(8+2) LED digits  Fully-merged keystroke entry (99 program steps)  Conditionals, Branching  20(7) numbers  Exponentials, Linear regression, Financial 

Voyagers

The first LCD product line from Hewlett-Packard contains some of the most successful, most popular calculators ever built. Of these machines, the HP-12C is still in production; the HP-15C remains one of the most sought after scientific calculator to date, and the HP-16C remains a favorite calculator for programmers. These machines were legendary for their amazingly low power consumption: many owners report that their machines still run on the original set of high-quality silver-oxide batteries after nearly 20 years!

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-10CHP-10CRPN Scientific  10(7+2) LCD digits  Fully-merged keystroke entry (79 program steps)  Conditionals, Branching  10(0) numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory 
Hewlett-Packard HP-11CHP-11CRPN Scientific  10(7+2) LCD digits  Fully-merged keystroke entry (203 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  20(0) numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory 
Hewlett-Packard HP-12CHP-12CFinancial  10(7+2) LCD digits  Fully-merged keystroke entry (99 program steps)  Conditionals, Branching  20(7) numbers  Exponentials, Linear regression, Financial, Continuous memory 
Hewlett-Packard HP-12C PlatinumHP-12C PlatinumFinancial  10(7+2) LCD digits  Fully-merged keystroke entry (400 program steps)  Conditionals, Branching  20 numbers  Exponentials, Linear regression, Financial, Continuous memory 
Hewlett-Packard HP-15CHP-15CRPN Scientific  10(7+2) LCD digits  Fully-merged keystroke entry (455 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  65(0) numbers  Trigonometrics, Exponentials, Linear regression, Integration, Complex, Continuous memory, Matrix 
Hewlett-Packard HP-16CHP-16CN/A  10(7+2) LCD digits  Fully-merged keystroke entry (203 program steps)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  203(0) bytes  Continuous memory, baseN 

Coconuts

A stunning calculator even by today's standards, more than 20 years after its introduction, the HP-41C remains one of the best handheld calculating devices ever conceived. The HP-41C line remained in production for over 10 years, practically defining the high-end calculator industry throughout the 1980s. Numerous machines remain in use today, no doubt due in part to versatility offered by the calculator's four expansion ports. The HP-41C has been used in the most exotic places, including the Space Shuttle or the cockpit of the Concorde. The calculator's major (and perhaps only) fault is a less than robust construction, with screwposts that easily crack, internal pressure contacts that can fail unexpectedly, and a flexible circuit assembly subject to corrosion.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-41CHP-41CRPN Scientific  12 LCD 14-segment characters  Fully-merged keystroke entry (441 bytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  63(0) numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory, Sound 
Hewlett-Packard HP-41CVHP-41CVRPN Scientific  12 LCD 14-segment characters  Fully-merged keystroke entry (2233 bytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  319(0) numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory, Sound 
Hewlett-Packard HP-41CXHP-41CXRPN Scientific  12 LCD 14-segment characters  Fully-merged keystroke entry (2233 bytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  319(0) numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory, Real-time clock, Sound 
Hewlett-Packard HP-41 Option 001HP-41 Option 001RPN Scientific  12 LCD 14-segment characters  Fully-merged keystroke entry (2233 bytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  319(0) numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory, Sound 

Pioneers

HP's last pocket calculator line to date that contains keystroke-programmable models also featured another legendary calculator: the HP-42S. Built on the success of the HP-41C line, offering a similar programming model, a healthy 8 kB of memory, and even simple graphical capabilities, the HP-42S remains the most sought after engineering calculator today, even more than 5 years after HP ended its production for reasons known only to pointy-haired bosses...
This product line also contains the only two non-RPN keystroke programmables from HP: the HP-20S and the HP-21S. And to prove that perhaps those bosses are not so pointy-haired after all, they recently revived this line of calculators with the HP-33S, a reincarnation of the HP-32S with a great deal more memory and, for the RPN-haters among you, an algebraic mode.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-20SHP-20SScientific  12(9+2) LCD digits  Fully-merged keystroke entry (100 program steps)  Conditionals, Branching, Subroutines, Labels  10 numbers  Trigonometrics, Exponentials, Continuous memory, Equation library 
Hewlett-Packard HP-21SHP-21SScientific  12(9+2) LCD digits  Fully-merged keystroke entry (100 program steps)  Conditionals, Branching, Subroutines, Labels  10 numbers  Trigonometrics, Exponentials, Linear regression, Continuous memory, Equation library 
Hewlett-Packard HP-32SHP-32SRPN Scientific  12 LCD characters  Fully-merged keystroke entry (390 bytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  27(0) numbers  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Integration, Complex, Continuous memory, baseN 
Hewlett-Packard HP-32SIIHP-32SIIRPN Scientific  12 LCD characters  Fully-merged keystroke entry (390 bytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  27(0) numbers  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Integration, Fractions, Complex, Continuous memory, baseN 
Hewlett-Packard HP-32SII SilverHP-32SII SilverRPN Scientific  12 LCD characters  Fully-merged keystroke entry (390 bytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  27(0) numbers  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Integration, Fractions, Complex, Continuous memory, baseN 
Hewlett-Packard HP-33SHP-33SRPN Scientific  2×14 LCD characters  Fully-merged keystroke entry (32 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  32(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Integration, Fractions, Complex, Continuous memory, baseN, Unit conversions 
Hewlett-Packard HP-35SHP-35SRPN Scientific  2×14 LCD characters  Fully-merged keystroke entry (31 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  31(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Integration, Fractions, Complex, Continuous memory, baseN, Unit conversions, Constants 
Hewlett-Packard HP-42SHP-42SGraphing  131×16 LCD pixels  Fully-merged keystroke entry (7 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  7(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Complex, Financial, Continuous memory, Sound, Matrix, baseN, Unit conversions 

The HP Solver

Hewlett-Packard first introduced a built-in equation solver with the HP-34C. This solver function, however, operated on a traditional keystroke program. It wasn't until the Champion and Pioneer product lines that HP began producing a series of (mainly business) calculators in which a built-in solver represented the primary (or only) means of programming: user-defined formulae were entered using algebraic syntax, and the built-in solver isolated variables and solved for them numerically.

Pioneers

In addition to featuring several popular keystroke-programmable calculators, the Pioneer product line also included business models and algebraic scientific calculators with HP Solver functionality.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-17BHP-17BFinancial  131×16 LCD pixels  Formula programming (6700 kilobytes)  Conditionals, Branching  6700(0) bytes  Exponentials, Linear regression, Solver, Financial, Continuous memory, Sound, Matrix 
Hewlett-Packard HP-17BIIHP-17BIIFinancial  131×16 LCD pixels  Formula programming (6700 kilobytes)  Conditionals, Branching  6700(0) bytes  Exponentials, Linear regression, Solver, Financial, Continuous memory, Sound, Matrix 
Unconfirmed sightingHP-17BII+Financial  2×22 LCD characters  Formula programming (32 kilobytes)  Conditionals, Branching  32(0) kilobytes  Exponentials, Hyperbolics, Linear regression, Solver, Financial, Continuous memory, Sound, Matrix 
Hewlett-Packard HP-22SHP-22SScientific  12(9+2) LCD digits  Formula programming (371 bytes)    371(0) bytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Continuous memory, baseN, Unit conversions, Equation library 
Hewlett-Packard HP-27SHP-27SScientific  131×16 LCD pixels  Formula programming (6912 bytes)  Conditionals, Branching  6912(0) bytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Financial, Continuous memory, Real-time clock, Sound, baseN 

Champions

The Champion calculator line featured "folding" calculators. Although these calculators remained popular, the folding design wasn't universally loved, due to its fragility and the difficulty of using the calculators when held in one hand (or even both hands).

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-18CHP-18CScientific  137×32 LCD pixels  Formula programming (6700 kilobytes)  Conditionals, Branching  6700(0) bytes  Trigonometrics, Exponentials, Linear regression, Solver, Financial, Continuous memory, Sound, Matrix 
Hewlett-Packard HP-19BHP-19BScientific  137×32 LCD pixels  Formula programming (6700 bytes)  Conditionals, Branching  6700(0) bytes  Trigonometrics, Exponentials, Linear regression, Solver, Financial, Continuous memory, Sound, Matrix 
Hewlett-Packard HP-19BIIHP-19BIIScientific  137×32 LCD pixels  Formula programming (6700 bytes)  Conditionals, Branching  6700(0) bytes  Trigonometrics, Exponentials, Linear regression, Solver, Financial, Continuous memory, Sound, Matrix 
Unconfirmed sightingHP-19BII+N/A  LCD          

Programming with Aplets

While Hewlett-Packard continued to produce the highest quality calculators, it also continued to lose market share to other manufacturers, Casio and Texas Instruments the most notable among them, who focused on the lucrative educational market. An attempt to regain a foothold in this area was represented by the HP-38G, a graphing calculator with a new, education-oriented programming model: HP Aplets. The two newer models, the HP-39G and the HP-40G, represent a continuation of this concept. Along with these models, HP also introduced a low-cost scientific calculator, the HP-30S.

A Brave New World

Although it is officially not considered a programmable, the HP-30S nevertheless has a formula memory.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-30SHP-30SScientific  10+2 LCD digits  Formula programming (80 bytes)    11 numbers  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Solver, Fractions, Continuous memory, baseN 

Charlemagne

HP's last series of calculator products went through a series of revisions throughout a product lifetime that extends over a decade. An offshoot of this product line was a series of graphing educational calculators.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-38GHP-38GGraphing  131×64 LCD pixels  HP Aplets (32 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  32(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Sound, Matrix 
Hewlett-Packard HP-39GHP-39GGraphing  131×64 LCD pixels  HP Aplets (256 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  256(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Sound, Matrix 
No Image AvailableHP-39G+Graphing  LCD pixels        Graphing 
No Image AvailableHP-39GIIGraphing  LCD pixels        Graphing 
Hewlett-Packard HP-39GSHP-39GSGraphing  131×64 LCD pixels  HP Aplets (256 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  256(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Sound, Matrix 
No Image AvailableHP-40GGraphing  131×64 LCD pixels  HP Aplets (256 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  256(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Symbolics, Continuous memory, Sound, Matrix 
No Image AvailableHP-40GSGraphing  LCD pixels        Graphing 

Reverse Polish Language Graphing Calculators

In 1988, Hewlett-Packard introduced a stunning new machine. The HP-28C was not just a graphing calculator, it was also a calculator featuring a whole new programming model: the Reverse Polish Language. RPL successfully combines the ease and intuitiveness, not to mention the efficiency of keystroke macro programming with a sophisticted object model that puts "high-end" object oriented programming languages like C++ to shame.

Champions

The Champion series, recognizable for the folding "clamshell" design, featured HP's first modern RPL graphing calculators.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-28CHP-28CGraphing  137×32 LCD pixels  Reverse Polish Language (2 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  2(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants 
Hewlett-Packard HP-28SHP-28SGraphing  137×32 LCD pixels  Reverse Polish Language (32 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  32(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants 

Charlemagne

The Charlemagne product line continues to feature the most top-of-the line of all HP calculator models produced to date, the HP-49G, with an astounding 1.5 MB of memory capacity, and a sophisticated symbolic algebra capability.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-48GHP-48GGraphing  131×64 LCD pixels  Reverse Polish Language (32 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  32(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants, Equation library 
Hewlett-Packard HP-48G+HP-48G+Graphing  131×64 LCD pixels  Reverse Polish Language (128 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  128(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants, Equation library 
Hewlett-Packard HP-48GXHP-48GXGraphing  131×64 LCD pixels  Reverse Polish Language (128 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  128(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants, Equation library 
Hewlett-Packard HP-48GIIHP-48GIIGraphing  131×64 LCD pixels  Reverse Polish Language (128 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  128(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants, Equation library 
Hewlett-Packard HP-48SHP-48SGraphing  131×64 LCD pixels  Reverse Polish Language (32 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  32(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions 
Hewlett-Packard HP-48SXHP-48SXGraphing  131×64 LCD pixels  Reverse Polish Language (32 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  32(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions 
Hewlett-Packard HP-49GHP-49GGraphing  131×64 LCD pixels  Reverse Polish Language (512 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  512(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants, Equation library 
No Image AvailableHP-49G+Graphing  131×80 LCD pixels  Reverse Polish Language (512 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  512(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants, Equation library 
Hewlett-Packard HP-50GHP-50GGraphing  131×80 LCD pixels  Reverse Polish Language (1536 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  512(0) kilobytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Fractions, Complex, Symbolics, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN, Unit conversions, Constants, Equation library 
No Image AvailablePrimeGraphing  CLCD pixels        Graphing, Continuous memory 

Pocket Computers

The introduction of low-power C-MOS circuits, low-power liquid crystal displays, and high component density made it possible in the early 1980s to pack the power of an entire personal computer in a pocket-sized package. Hewlett-Packard joined the bandwagon with its BASIC-programmable computer/calculator products, that also inherited the flexible expandability of the HP-41 product line. Later, HP was among the first to produce MS-DOS compatible pocket computers, and remains a preeminent manufacturer of handheld Windows CE devices today.

BASIC computers

HP's BASIC-programmable handheld product line featured the HP-71B, the world's first pocket device featuring an ANSI-compatible floating point library.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-71BHP-71BScientific  22 LCD characters  BASIC (16 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  16(0) kilobytes  Trigonometrics, Exponentials, Continuous memory, Real-time clock, Sound, Magnetic cards 
Hewlett-Packard HP-75CHP-75CBASIC Programmable  32 LCD characters  BASIC (16 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  16(0) kilobytes  Trigonometrics, Exponentials, Continuous memory, Real-time clock, Sound, Magnetic cards 
Hewlett-Packard HP-75DHP-75DBASIC Programmable  32 LCD characters  BASIC (32 kilobytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  32(0) kilobytes  Trigonometrics, Exponentials, Continuous memory, Real-time clock, Sound, Magnetic cards 

MS-DOS computers

The HP-95LX was one of the world's first pocket computers offering true MS-DOS compatibility; the HP-200LX, although discontinued years ago, remains a popular PDA even today.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP-95LXHP-95LXGraphing  240×128 LCD pixels  Spreadsheet data (1 megabytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  1(0) megabytes  Trigonometrics, Exponentials, Linear regression, Graphing, Solver, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN 
Hewlett-Packard HP-100LXHP-100LXGraphing  640×200 LCD pixels  Spreadsheet data (1 megabytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  1(0) megabytes  Trigonometrics, Exponentials, Linear regression, Graphing, Solver, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN 
Hewlett-Packard HP-200LXHP-200LXGraphing  640×200 LCD pixels  Spreadsheet data (1 megabytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  1(0) megabytes  Trigonometrics, Exponentials, Linear regression, Graphing, Solver, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN 
Hewlett-Packard HP-700LXHP-700LXGraphing  640×200 LCD pixels  Spreadsheet data (1 megabytes)  Conditionals, Branching, Subroutines, Labels, Indirect addressing  1(0) megabytes  Trigonometrics, Exponentials, Linear regression, Graphing, Solver, Financial, Continuous memory, Real-time clock, Sound, Matrix, baseN 

One Of A Kind

The Xpander was a dream that never happened: an educational product based on the Windows CE 3.0 operating system.

- Model Type Display Programming model Programming features Memory Special functions
Hewlett-Packard HP XpanderHP XpanderGraphing  240×320 LCD pixels  Formula programming (8 megabytes)  Subroutines  8(0) megabytes  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Solver, Integration, Continuous memory, Matrix 

Other Models

Hewlett-Packard models that were not yet added to any of the categories listed so far are shown below.

- Model Type Display Programming model Programming features Memory Special functions
No Image AvailableHP-30BRPN Scientific  LCD digits  ( program steps)  Conditionals, Branching, Subroutines    Trigonometrics, Exponentials, Solver, Financial, Continuous memory 
No Image AvailableHP-9GGraphing  35×23 LCD pixels  Formula programming (400 program steps)  Conditionals, Branching, Subroutines, Labels  26 numbers  Trigonometrics, Exponentials, Hyperbolics, Linear regression, Graphing, Fractions, Complex, Continuous memory, baseN, Unit conversions, Constants 

Variants/OEM Versions

Some Hewlett-Packard calculators were sold in Japan under the brandname Yokogawa-Hewlett-Packard (YHP). Model numbers remained the same.