HP-67
| Industry | Electronics, Computing |
|---|---|
| Founded | January 1, 1939 |
| Headquarters | Palo Alto , United States |
| Products | HP-67 programmable calculator, HP-97 desktop calculator |
The HP-67 is a handheld calculator programmable via magnetic cards, introduced by Hewlett-Packard in 1976 with a retail price of $450. Its desktop counterpart, the HP-97, which includes an integrated thermal printer, was offered at $750. Together, these devices are commonly referred to as the HP-67/97 series.
Presented as advanced replacements for the HP-65, the HP-67 and HP-97 were built upon the "20-series" platform (which includes models like the HP-25 and HP-19C) unveiled the previous year. Both units share identical functionality, and programs stored on magnetic cards are compatible across the two models.
Features
The HP-67/97 calculators provide an extensive range of scientific, engineering, and statistical capabilities, encompassing trigonometric calculations, logarithms, exponentials, coordinate system transformations, averages, and standard deviation computations.
These devices incorporate 224 memory words of eight bits each, enabling "fully merged keycodes" that optimize program storage efficiency. Their programming environment supports up to 20 labels, subroutines nested three levels deep, four flag registers, eight comparison operations, along with sophisticated indexing and looping mechanisms.
Their 15-digit LED display surpasses earlier models in width; notably, the decimal point occupies a unique digit position. The HP-67’s keyboard allows up to four functions per key accessible through prefix keys labeled "f," "g," and "h" (color-coded gold, blue, and black). In contrast, the HP-97’s larger keypad assigns two functions per key. When transferring magnetic card programs between these calculators, software automatically translates key codes and simulates the HP-97’s printing output on the HP-67’s display.
Powering the HP-67 are three AA-sized nickel-cadmium rechargeable batteries. The HP-97 requires a bulkier battery pack coupled with a charger to meet the energy demands of its thermal printer.
Memory and programming
The data memory consists of 26 registers: ten "primary registers" accessible directly, an additional ten serving as an alternate set, and six more accessible via user-defined keys A through E plus an index register. This configuration allowed programmers to treat all 26 registers as a single indexed array. Data stored in memory was volatile and lost upon power-off. The alternate register set also facilitated statistical calculations.
Equipped with an integrated magnetic card reader/writer, these calculators could save programs and data onto cards and merge information from multiple cards. This magnetic card format was subsequently adopted by the HP-41C model, ensuring backward compatibility through software emulation. Hewlett-Packard provided a collection of pre-recorded magnetic card packs tailored for applications in fields such as surveying, medicine, civil engineering, and electrical engineering. Users could protect cards from being overwritten by physically removing a designated corner.
Beyond official support and software from HP, an active user community known as PPC produced the PPC Journal and developed modifications like the "Blackbox," which enabled limited pseudo-alphanumeric display capabilities.
A specialized version featuring an additional backward-facing display—the EduCALC 67 GD—was manufactured by Educational Calculator Devices.
HP-97S
In 1977, Hewlett-Packard released the HP-97S, an upgraded desktop variant that included an extra parallel I/O port (providing 40 lines for ten 4-bit BCD digits plus five control lines) designed to connect with external equipment. This model was priced at $1,375.