HP-44A
| Industry | Computer hardware |
|---|---|
| Founded | January 1, 1939 |
| Products | HP-71B pocket computer |
The HP-71B was a portable computing device programmable in BASIC, manufactured by Hewlett-Packard between 1984 and 1989.
Description
Compared to its predecessor, the HP-75, the 71B was more compact and cost-effective. It offered a single-line liquid crystal display capable of showing 22 characters, along with 64K of system ROM and 17.5K available for user programs. The initial retail price in 1984 was US$595. Power was supplied either by four AAA batteries or an AC adapter. Expansion was possible through four plug-in ports designed for adding ROM-based applications or increasing user memory. Optional modules included a magnetic card reader and an HP-IL interface (model HP 82401A), which facilitated connections to printers, storage devices, and electronic test instruments.
Notably, the 71B was the first handheld device to support the IEEE 854-1987 floating-point standard, which is independent of radix. Its programming features encompassed a real-time clock, programmable timers, subroutine invocation with parameter passing, and recursive functions. This calculator marked HP's initial use of the Saturn processor, which later became the core of the popular HP-48 series and many other HP calculator lines.
The magnetic card reader saw limited adoption due to its constrained storage capacity—only two tracks holding 650 bytes each. More substantial storage solutions were available through HP-IL peripherals such as the 82161A cassette drive and the 9114A diskette drive; although portable, these units were bulkier compared to the 71B itself. Additionally, third-party memory expansion modules were designed to fit into the card reader slot.
Other aftermarket accessories included a bar code wand and application ROMs compatible with the memory expansion ports. A configuration combining the bar code wand with specialized software found extensive use in data collection efforts by the British Department of Health and Social Security (DHSS).
Unlike models such as the HP-75 or HP-41, the 71B could function as a device within an HP-IL loop controlled externally, allowing multiple units to intercommunicate or share peripherals. When paired with an HP 82402 Dual HP-IL controller, a single 71B could connect to two separate HP-IL loops simultaneously—acting as controller on one loop while serving as a device on the other.
An optional plug-in ROM provided compatibility with software developed for the HP-41 series, emulating its environment at approximately five times the original speed.
Internal Design Specification
A unique feature of the HP-71B was Hewlett-Packard’s public release of comprehensive Internal Design Specification (IDS) documents that revealed nearly complete engineering details. Four IDS volumes covered software aspects within the 71B’s ROM, including full assembly language source code alongside thorough design notes. Additional IDS materials addressed hardware components, the Forth/Assembler add-in ROM, and the HP-IL controller add-in module.
External links
- HP-71B at the MoHPC
- HP Journal, July 1984 Issue dedicated to HP-71B design and packaging (featuring exploded diagrams)
- HP-71B images hosted on MyCalcDB, a repository for calculators from the 1970s and 1980s
- HP-71B Compendium – detailed information about this handheld computer
- HP-71 Reference Manual