HP 49g+

HP 49/50 series

Company type	Product line
Industry	Consumer electronics
Predecessor	HP 48 series
Founded	1999
Headquarters	Palo Alto , United States
Products	Graphing calculators (HP 49G, hp 49g+, hp 48gII, HP 50g)
Owner	Hewlett-Packard

The HP 49/50 series represents a line of graphing calculators developed by Hewlett-Packard, which succeeded the HP 48 series. This lineup comprises five distinct models that offer both algebraic and RPN input options. They are capable of performing numeric as well as symbolic computations via an advanced CAS, integrating enhancements derived from the HP 48's ALG48 and Erable frameworks.

These calculators are highly regarded for their sophisticated features, catering to professionals across fields such as engineering, scientific research, surveying, mathematics, linear algebra, physics, statistics, numerical analysis, and computer science. Although production has ceased, persistent demand maintains their strong resale market value.

HP 49G

Introduced in August 1999, the HP 49G (models F1633A, F1896A) incorporated robust mathematical capabilities and interfaces from the HP 48 series within upgraded firmware. It supported on-device compilation and decompilation of both SysRPL and Saturn assembly language.

Significantly, the 49G was HP's inaugural calculator to feature flash memory alongside firmware that could be updated. It came with a durable sliding hard case, replacing the softer protective pouches used previously. Its internal hardware shares similarities with the HP 39G and HP 40G models.

The last official firmware release was version 1.18, followed by unofficial updates reaching up to version 1.19-6. Additionally, emulator versions designed for successor models' ARM-based CPUs were backported to support the original 49G up through firmware iteration 2.09.

In 2003, HP made the CAS source code available under the LGPL license, including an interactive geometry application and compatibility utilities for newer devices. Nevertheless, licensing terms prohibit redistribution of recompiled firmware binaries.

hp 49g+

Launched in August 2003, the hp 49g+ (F2228A) featured a distinctive metallic gold exterior and maintained full backward compatibility with the HP 49G. Developed and produced by Kinpo Electronics on behalf of HP, it introduced a new processor architecture along with USB Mini-B and IrDA infrared communication interfaces, SD card memory expansion capabilities, and a marginally larger display.

This model operates using an emulation layer for legacy Saturn processors rather than executing directly on the ARM920T core. The firmware largely mirrors that of the HP 49G but incorporates patches that substitute certain code segments with "Saturn+" instructions running natively on ARM hardware to enhance performance. This design ensured binary-level compatibility with most HP 49G software and source-level compatibility with numerous HP 48 series programs.

Despite the overhead introduced by emulation, the 49g+ achieves performance gains ranging from three to seven times faster than the HP 49G. It also supports native execution of ARM programs, completely bypassing emulation when utilized. For advanced development on this platform, a port of the GNU C compiler (HPGCC) is available.

hp 48gII

Unveiled on October 20, 2003, the hp 48gII (F2226A) was not intended as a direct successor to the HP 48 series, despite its naming convention. Essentially, it is a variant of the 49g+ equipped with an ARM processor but features reduced memory capacity, lacks SD card expansion, operates at a lower clock speed, includes a smaller screen, and utilizes non-flashable firmware. This model targeted users requiring robust mathematical functionality without extensive program installations. The initial release in 2003 offered 128 KB of RAM and operated on three AAA batteries. A revised edition in 2007 (based on the Apple V2 platform) doubled RAM to 256 KB, added a USB Mini-B port, enhanced keyboard design, and increased battery requirements to four AAA cells.

HP 50g

Introduced in 2006 and discontinued in 2015, the HP 50g (F2229A) represents the final evolution of the 49/50 calculator series, succeeding the HP 49g+. It retains the classic HP aesthetic with a black casing complemented by white, orange, and yellow function keys. The rear shell features a textured finish to enhance handling. To accommodate users with color vision deficiencies, high-contrast editions in blue and white were released during 2009/2010 and again in 2011/2012.

The HP 50g preserves the form factor of its predecessor, the 49g+, but upgrades power requirements to four AAA batteries instead of three. It encompasses all functionalities of the 49g+ along with the complete equation library from the HP 48 series, integrated from firmware versions 2.15/2.16 onward. Additionally, it includes the periodic table library that was initially introduced as a plug-in for the HP 48S. For connectivity, it offers USB Mini-B, an infrared IrDA port with a limited effective range of approximately 10 cm, and a proprietary asynchronous serial port operating at 3.3 V TTL levels; this port requires an adapter to interface with RS-232 standards.

The keyboard design incorporates hinged keys—a feature first introduced late in the production run of the 49g+—addressing previous user feedback on key responsiveness. Firmware remains largely compatible with that of the 49g+, benefiting from ongoing automatic updates during its development phase.

Officially launched worldwide by HP in September 2006, the HP 50g was the company’s last calculator model to support RPL. Later devices such as the HP Prime transitioned exclusively to RPN-based systems like Advanced RPN.

Programming

Calculators in the HP 49/50 series accommodate both algebraic input and a stack-oriented programming language known as RPL, which merges concepts from Reverse Polish Notation (RPN) and the Lisp paradigm. RPL extends stack-based programming by introducing lists and functions, allowing unevaluated code fragments to be passed or returned on the stack.

At the highest level is User RPL, a language that employs built-in postfix commands with optional control structures such as loops and conditional execution. Each instruction verifies its stack arguments and emits errors if they do not meet expected criteria.

Beneath User RPL lies System RPL (SysRPL), which omits argument validation and is optimized for specific data types (for example, differentiating between short and long integers). This results in SysRPL programs running significantly faster and granting access to more advanced capabilities unavailable in User RPL. Developers can write System RPL code directly on the calculator using MASD, an integrated compiler that also supports assembly programming for the Saturn CPU and—on models like the 49g+ and 50g—compiles ARMv4T assembly when running updated firmware. A variety of tools exist to support this programming ecosystem.

Assembly language programming is supported for both the Saturn processor and, on 49g+/50g units, ARM assembly as well as C, typically via desktop-based compilers. For additional resources, see programs developed for the HP 48 series. None of these calculators provide native support for programming in HP PPL.

HPGCC for the 49g+/50g

HPGCC is a compiler based on the GCC released under the GNU General Public License (GPL), specifically designed for ARM-powered calculators such as the HP 49g+ and HP 50g. Earlier versions offered support for other ARM models including the 48gII and HP 39g+/39gs/40gs but were discontinued due to limited user interest and compatibility challenges. HPGCC functions as a cross-compiler: it executes on personal computers but generates executable code tailored for HP calculators.

By default, HPGCC produces ARM Thumb mode code, which minimizes binary size with negligible impact on performance. It implements most of the ANSI C standard alongside device-specific libraries that facilitate interaction with calculator features such as the RPN stack, memory management, and buzzer control. Although GCC itself imposes no restrictions on compiled output licensing, HPGCC’s accompanying libraries are distributed under a modified GPL license requiring that linked programs also be GPL-licensed unless classified as "non-profit" software.

Versions of HPGCC are available for Linux, Windows, and Mac OS X platforms. The Windows release includes Programmer's Notepad as a simple integrated development environment (IDE).

Emulators

A variety of emulators have been developed for the HP 49G calculator. Among them, the Debug4x IDE incorporates EMU48, which replicates most functions of the 49g+/50g models; however, it lacks the ability to execute ARM-based software.

The x49gp emulator, designed for ARM architecture, offers full emulation of the 49g+/50g ARM processor and is compatible with programs compiled using HPGCC versions 2 and 3. It is available on Linux and Mac OS X, but it requires manual compilation from source code.

Additionally, the commercial m48 program supports the HP 49G platform. Emulators for smartphones remain limited; for instance, the HP 50g has been accessible on iPhone and iPad devices since 2012. There is also an emulator for Windows Mobile, while Android emulators exist but generally lack ARM compatibility.

In 2012, Hewlett-Packard launched the HP 50g Virtual Calculator for Windows (versions 3.1.29/3.1.30), which includes firmware 2.16 and supports StreamSmart 410.

Firmware updates

Firmware upgrades are supported on the 49/50 series to improve functionality or resolve software issues. Hewlett-Packard supplies official update packages, and unofficial firmware versions can be found on platforms like hpcalc.org.

Further reading

• [1]
• [2]
• [3] Searchable
• (Catalog of known firmware bugs, both resolved and outstanding.)
• (Discussion regarding unresolved firmware problems.)
• (Forum discussion thread addressing firmware concerns.)

External links

• Official Hewlett-Packard support pages for HP 49G, hp 48gII, hp 49g+, and HP 50g
• Comprehensive resources for HP 49/50 series at www.hpcalc.org
• HP 50g software collections by Software49
• HP 50g software offerings by Heuson-Software