HP-45

HP-45. The HP-45 was a groundbreaking scientific calculator introduced by Hewlett-Packard in 1973 as the successor to the revolutionary HP-35. It was the world's first handheld calculator with a programmable memory and an expanded suite of scientific functions, solidifying Hewlett-Packard's dominance in the professional electronics market. The device featured a distinctive Reverse Polish Notation (RPN) logic system and became an essential tool for engineers, scientists, and students worldwide.

History and development

Following the immense success of the HP-35, Hewlett-Packard engineers, led by figures like Thomas E. Osborne, sought to create a more powerful model. Development aimed to address user feedback requesting additional functions and memory, while maintaining the robust build quality of its predecessor. The project culminated in an announcement at the National Radio Astronomy Observatory and a subsequent launch at the Joint Computer Conference in 1973. Its release was strategically timed to outpace competitors like Texas Instruments and Commodore International in the burgeoning personal computing arena.

Features and specifications

The HP-45 was notable for its Red LED display and its use of the proprietary HP Nut microprocessor. It offered 9 addressable memory registers, a significant upgrade from the HP-35, and included key new functions such as degrees-minutes-seconds conversions, rectangular-to-polar coordinate conversions, and a dedicated percent key. Physical features included a sleek anodized aluminum case and a keyboard made of injection-molded keys. Power was supplied by a built-in rechargeable battery system, with an optional AC adapter available.

Programming and functions

While not fully programmable in the sense of later models like the HP-65, the HP-45 introduced a form of programmable memory through its 9 storage registers and Last X register. This allowed users to chain complex calculations. Its mathematical core supported advanced functions including hyperbolic functions, factorial computation, and statistical operations like mean and standard deviation. The unwavering use of Reverse Polish Notation (RPN) eliminated the need for parentheses and increased operational efficiency, a hallmark of Hewlett-Packard calculators.

Impact and legacy

The HP-45 had a profound impact on technical professions, effectively making the slide rule obsolete and becoming a standard issue for organizations like NASA and the United States Army. It cemented Hewlett-Packard's reputation for high-quality, innovative consumer electronics and established a loyal user base within the engineering community. The model directly paved the way for the fully programmable HP-65 and the legendary HP-41C. Today, it is a highly sought-after item among collectors of vintage computing technology.

Technical details

Internally, the calculator utilized three ROM chips and one RAM chip, with logic design overseen by William E. Wickes. The HP Nut processor ran at a clock speed of approximately 200 kHz. The display consisted of a 15-digit Red LED screen capable of showing numbers in scientific notation. Its precision was up to 10 digits for internal calculations, using binary-coded decimal arithmetic. The device's electrical design was patented in the United States Patent and Trademark Office, and it complied with emerging Federal Communications Commission regulations on digital device emissions.

Category:Calculators Category:Hewlett-Packard Category:1973 introductions