HEXCALC

Hewlett-Packard

Industry	Computer hardware
Founded	January 1, 1939 (1939-01-01)
Headquarters	Palo Alto, California , United States

The HP 200LX Palmtop PC (models F1060A, F1061A, F1216A), originally developed under the codename Felix, is a personal digital assistant launched by Hewlett-Packard in August 1994. This device stood out as a DOS-compatible handheld computer equipped with a monochrome graphic screen, a QWERTY keyboard, a serial interface, and a PCMCIA expansion slot. The designation "LX" signifies "Lotus Expandable".

Description

The HP 200LX is designed with a compact clamshell form factor featuring a miniature QWERTY keyboard alongside a numeric keypad, measuring approximately one-quarter the size of a conventional laptop. It is powered by two AA alkaline or Ni-Cd rechargeable batteries, delivering around 30 to 40 hours of operation, with recharging facilitated through a 12 V DC power adapter.

Under the hood, it utilizes an Intel 80186-compatible "Hornet" processor running at roughly 7.91 MHz, which can be overclocked to about 15.8 MHz. Memory options include 1, 2, or 4 MB configurations, with 640 KB allocated as RAM and the remainder serving as expanded memory (EMS) or storage space. Third-party memory upgrades can increase capacity up to 64 MB, thereby freeing the PCMCIA slot for modem or Ethernet card usage; supported network cards include models from Silicom, Accton, Netgear FA411, and Sohoware ND5120. The system boots MS-DOS 5.0 from ROM and maintains IBM PC/XT compatibility, enabling it to run most Intel 8086/8088/80186-targeted applications with CGA graphics support and certain 80286 programs that do not require protected mode.

Connectivity options consist of a Type II PCMCIA slot (operating at 5 V with a maximum current of 150 mA), an Infrared Data Association (IrDA) SIR-compatible infrared port, and a full serial port accessible via a proprietary mini connector.

The integrated ROM-based software package includes Lotus 1-2-3 Release 2.4 spreadsheet, calendar functions, a phone directory, terminal emulation capabilities, Lotus cc:Mail client, along with scientific and business calculators. With sufficient CompactFlash storage and an attached serial mouse, it is capable of running Microsoft Windows 3.0 in Real Mode—albeit constrained by hardware limitations—and supports Word 1.x and Excel 2.x applications compatible with MS Office file formats.

Its monochrome LCD delivers CGA-compatible graphics at a resolution of 640×200 pixels with four grayscale levels but does not include backlighting; aftermarket electroluminescent backlight solutions became available after 2004.

While standard CGA displays typically use hardware code page 437 fonts exclusively, the HP 95LX model supported code page 850. Starting from the HP 100LX onward, the LX series introduced user-selectable text mode ROM fonts for code pages 437 and 850 along with software-definable RAM fonts allowing additional code page support. Lotus 1-2-3 employs the Lotus International Character Set (LICS), which maps characters to code page 850 for both display and printing purposes.

HP 100LX

The HP 100LX Palmtop PC (model numbers F1020A for the 1 MB version and F1022A for the 2 MB variant), also known as project Cougar, was introduced before the HP 200LX in 1993. Offered in International English, U.S. English, French, German, and Spanish editions—with localized keyboards and language-specific messages—it shares the Hornet CPU and MS-DOS 5.0 operating system but includes earlier versions of the built-in applications.

HP Palmtop FX

Introduced in 1993, the HP Palmtop FX represents a variation of the HP 100LX, featuring up to 2 MB of flashable memory. This model supported writable FAT flash disk images through a dedicated utility. Allegedly created for a Korean insurance firm, it provided users with improved storage adaptability.

HP 200LX AIA

The HP 200LX AIA was a specialized edition of the HP 200LX with 2 MB and double-speed capabilities, manufactured exclusively for American International Assurance (AIA) to fulfill specific corporate requirements.

HP 1000CX

Known internally as project Puma, the HP 1000CX Palmtop PC came in two versions: F1203A with 1 MB released in March 1995 and F1222A with 2 MB launched in February 1997. This economical alternative to the 200LX lacked built-in software except for MS-DOS 5.0 embedded in ROM. It found extensive use in companies such as Coca-Cola for customized logistics solutions. Its design featured a black clamshell case, setting it apart from the dark green color scheme of the 200LX.

HP OmniGo 700LX

The HP OmniGo 700LX Communicator Plus (F1206A), codenamed Columbia, was developed by HP’s calculator division based in Singapore. It combined a modified motherboard from the HP 200LX with a Nokia 2110 GSM phone, connected via a second PCMCIA slot using a piggyback configuration. Announced in late 1995 and shipped starting March 1996, this device targeted professionals requiring wireless communication on the move. Production ceased once the Nokia 2110 became outdated. The OmniGo 700LX anticipated features later common in smartphones such as the Nokia Communicator 9000.

HP 95LX

Launched in April 1991 under project Jaguar, the HP 95LX Palmtop PC (F1000A with 512 KB and F1010A with 1 MB) laid the foundation for palmtop design. Powered by a NEC V20 CPU running at 5.37 MHz, it operated on MS-DOS 3.22 and included Lotus 1-2-3 Release 2.2 pre-installed. Its quarter-CGA resolution LCD and MDA-compatible graphics limited compatibility with many PC applications but delivered essential spreadsheet capabilities tailored for business users.

HP OmniGo 100

The HP OmniGo 100 Organizer Plus (models F1305A and F1310A) was conceived as an advanced successor to the LX series, incorporating functionality from the HP-12C calculator. It featured a graphical user interface navigated by pen input or keyboard but lacked support for running unmodified DOS software. Its main operating environment was DOS-based PEN/GEOS version 2.1, which included Graffiti handwriting recognition on top of Datalight ROM-DOS 6.22. Despite these features, it failed to replace calculators effectively, as Palm devices and Pocket PCs dominated the PDA market. The unit contained 1 MB of RAM and was powered by a Vadem VG230/V5H system controller paired with a 16 MHz NEC V30HL CPU compatible with the Intel 80186 instruction set.

Current usage

Although HP discontinued this line in favor of their Windows CE offerings beginning with the HP 300LX, the HP OmniGo 100 retained interest due to its MS-DOS foundation, which supported extensive desktop software including bundled applications like Lotus 1-2-3 and Quicken. Compared to Windows CE devices, DOS applications were typically smaller and more efficient, while utilities such as Software Carousel enabled multitasking across multiple programs.

Third-party services continue to provide upgrades and repairs to prolong device usability.

Particularly favored in Japan for its compactness and DOS compatibility, the HP 200LX inspired an open-source project initiated by to create a successor based on the AMD Élan SC400 platform in 2001. Nonetheless, only one prototype emerged before the company declared bankruptcy in 2003 amid disputes over lost deposits. Project leaders attributed setbacks to component shortages driven by mobile phone industry demands.

Typical issues

• Cracks frequently appear on the right hinge of the injection-molded case top, caused by inadequate molding flow. Repairs often involve reinforcing the area using industrial-strength super glue or epoxy combined with metal braces.
• The latch that secures the case opening can malfunction but is straightforward to repair by inserting a slim rubber or silicone piece to act as a spring.
• To avoid battery leaks that may harm the LCD flat video cable, only premium-quality AA rechargeable batteries should be used.
• Older models might experience loss of pixel columns due to detachment of the display chip pins; re-soldering these pins can often restore proper function.
• Intensive use can cause the spacebar or enter keys to become detached, necessitating a keyboard replacement.
• The flexible strip linking the screen and motherboard is prone to tearing from friction and generally requires replacement when damaged.
• Non-responsive keys are commonly caused by deteriorated graphite pads on the keyboard ribbon losing contact. Repair methods include applying conductive silver paint or copper tape to reestablish connectivity. Corroded motherboard pads can be cleaned and smoothed using fine steel wool. These repairs demand careful handling of electronic components during reassembly.

Deviations from full IBM PC compatibility

• The HP 100LX/200LX’s digital-to-analog converter does not support audio tone playback; instead, it is utilized for monitoring battery status and charging.
• This device does not include the BIOS service (INT 13h) required for hard disk access. Partial device driver development has enabled booting MINIX 2.0 on it.

Additional information

• The HP 200LX was employed during NASA’s Discovery OV103 Mission STS-95 (John Glenn’s last flight) as part of an Electronic Nose experiment created by Jet Propulsion Laboratory (JPL) and California Institute of Technology (Caltech), overseen by Dan Karmon at JPL.
• It is capable of playing video and audio files via software developed by Stefan Peichl, albeit at limited quality, and supports audio recording. No PCMCIA sound cards are compatible, but Yamaha MU10 MIDI sound modules function through the serial port using Voyetra or GSPlay MIDI applications. Terrence Vergauwen utilizes a PCMCIA parallel port card in conjunction with an OPL3LPT (Adlib-compatible) sound card for gaming purposes.
• Both software and hardware solutions exist that allow the HP 200LX to connect to the Internet.
• Serial numbers for HP 100LX, 200LX, 1000CX, and OmniGo 700LX devices follow this structure:

XXYWWNNNNN

XX = country of manufacture (e.g., SG = Singapore)

Y = last digit of production year (e.g., 6 = 1996)

WW = week number within that year

NNNNN = sequential unit number produced during that week

Hidden features

The HP 200LX contains multiple easter eggs, including:

Secret gallery

Within the built-in game "Lair of Squid," entering "gallery" (translated according to language settings) during startup opens a maze segment showcasing photos of key software developers:

• Andy Gryc
• Pat Megowan
• Everett Kaser
• Bill Johnson
• Lynn Winter
• Susan Wechsler
• Eric Evett

The final screen displays a message expressing gratitude:

Self-test limerick

In the HP 200LX self-test mode—activated by pressing with the device off and selecting the display option—pressing fourteen times reveals a limerick poem:

Second self-test poem

Within the HP 200LX self-test interface, pressing , then holding while pressing 13 times unveils a mysterious poem that conveys the software team's business obstacles:

Third self-test poem

Using the same self-test mode, pressing , then holding while pressing 13 times displays a metaphorical poem chronicling the progression of HP LX palmtops—highlighting project codenames Jaguar (95LX), Cougar (100LX), and Felix (200LX), with Felix marking the addition of Quicken support:

Concealed development feature in 'More Applications'

Inside the HP 200LX System Manager, by holding and pressing four times followed by once (after launching 'More Applications' via the blue key), users can access comprehensive information about System Manager-compatible (.EXM) software and other internal data—presumably designed as a developer utility rather than a hidden surprise.

Undocumented hexadecimal calculator

The HP 200LX houses a hidden calculator app called HEXCALC, created by Andrew Gryc. This tool facilitates arithmetic and logic operations in binary, octal, decimal, and hexadecimal formats. It is accessible through the applications menu under:

• Name: He&x Calc
• Location: D:\BIN\HEXCALC.EXM

See also

• HP 110 / HP 110 Plus
• DIP Pocket PC / Atari PC Folio / Atari Portfolio
• Poqet PC
• Poqet PC Prime
• Poqet PC Plus
• ZEOS Pocket PC
• Ben NanoNote
• Sub-notebook (HP OmniBook)
• Netbook
• Palmtop PC
• Ultra-mobile PC

Further reading

• The Evolution of the HP Palmtops – An HP engineer's account of developing the HP 95LX and HP 100LX.
• The First Real Palmtop – A review of the pioneering handheld computer.
• The story of the 1991 HP DOS Palmtop – Transition from advanced calculator to full DOS-compatible device.
• Rob Tillotson's Review of the HP 200LX.
• Sy's evaluation of the HP 200LX.
• Articles covering NASA's STS-95 E-Nose experiment.
• Application of off-the-shelf HP 200LX by "Shade Tree Engineer."
• The Electronic Nose and Quadrupole Mass Spectrometer Array details.
• Findings from the Space Shuttle STS-95 Electronic Nose mission.
• HP 200LX profile featured at Old-Computers.com Museum.

External links

• 200LX Software S.U.P.E.R. – Collection of over 1500 programs and 200 databases for the 200LX
• HP Palmtop Paper Online – Marketplace and repair resources
• HP Palmtop Ring Homepage
• Skolob's Hewlett Packard 95LX Palmtop Page – Information and FAQs about the HP 95LX
• Networking on an HP palmtop – Compatibility overview for Sohoware ND5120 network card